MA-SEM-II-Evolutionary-Psychology-munotes

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FOUNDATION OF EVOLUTIONARY
PSYCHOLOGY - I
Unit Structure
1.0 Objectives
1.1 Introduction
1.2 Landmarks in the History of Evolutionary Thinking
1.2.1 Darwin‘s Theory of Natural Selection
1.2.2 Darwin‘s Theory of Sexual Selection
1.2.3 The Role of Natural Selection and Sexual Selection in
Evolutionary Theory
1.3 Movements and Controversies in Evolutionary Thinking
1.4 Common Misunderstandings about Evolutionary Theory
1.5 Origins of human nature, evolutionary game theory
1.6 The Three Products of Evolution
1.7 Levels of Evolutionary Analysis in Evolutionar y Psychology
1.8 Two Strategies for Generating and Testing Evolutionary Hypotheses
1.9 Evolutionary game theory
1.10 Summary
1.11 Questions
1.12 Summary
1.0 OBJECTIVES After studying this chapter, the reader will be able to understand
 Darwin‘s Theory of Natural Selection
 Darwin ‘s Theory of Sexual Selection
 Movements and Controversies in Evolutionary Thinking
 Common Misunderstandings about Evolutionary Theory
 Origins of human nature, evolutionary game theory
 Key products of evolution
 Concept of ―evolved psychological mechanism.‖
 Methods for testing evolutionary hypotheses
 Data sources for testing evolutionary hypotheses.
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2 1.1 INTRODUCTION Evolutionary psychology is a theoretical approach to psychology that
attempts to explain useful mental and psychological traits —such as
memory, perception, or language —as adaptations, i.e., as the functional
products of natural selection.
Evolutionary psychology is focused on how evolution has shaped the mind
and behaviour. Most research in evolutionary psychology focuses on
humans.
Evolutionary P sychology proposes that the human brain comprises
many functional mechanisms, called psychological adaptations or
evolved cognitive mechanisms designed by the process of natural
selection. Examples include language acquisition modules, incest
avoidance mec hanisms, cheater detection mechanisms, intelligence and
sex-specific mating preferences, alliance -tracking mechanisms, and so on.
Evolutionary psychology has roots in cognitive psychology and
evolutionary biology.
It also encompasses behavioural ecology, a rtificial intelligence, genetics,
ethology, anthropology, archaeology, biology, and zoology. It is also
linked to socio -biology.
What Is Evolutionary Psychology?
The human body evolved over thousands of years, slowly calibrating to
the African savannah on which 98 percent of human ancestry lived and
died. According to evolutionary psychologists, the mind is shaped by the
pressure to survive and reproduce; emotions, communication skills, and
language ability are adaptations that enabled ancestors to thrive.

Many of the behaviours humans exhibit have been tools for self -
preservation: People jealously guard their romantic partners, and
competition for mates has always been harsh. Everyone cherishes their
closest kin; preserving genes is in one‘s best interest. Humans also crave
social in teraction to encourage cooperation , further increasing the chances
for survival. Many of these behaviours are innate; often how people react
and i nteract with one another is spelt out in DNA.
Helping to Explain Who We Are :
Our emotional complexity helps differentiate us from other members of
the animal kingdom. Evolutionary psychology seeks to explain how our
emotions and other aspects of being hum an served the advantages of our
ancestors. Like other social primates, we experience emotions beyond
primal fear and anger —through evolving as a group, we have
developed empathy and altruism , which allow us to commiserate with
each other‘s situations and act in ways that are not self -serving.
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3 Foundation of Evolutionary Psychology - I We have also developed emotions to help keep us in line,
forexample, shame motivates us to atone for past transgressions, while
pride pushes us to remain in high regard by our peers. As our social
structures developed, so did our value systems —what we define as ―right‖
and ―wrong.‖
Evolutionary Psychology & Human Behaviour :
Evolutionary psychology is a scientific discipline that approaches human
behaviour through a lens that incorporates the effects of evolut ion. It
combines the science of psychology with the study of biology.
Evolutionary psychologists seek to explain people's emotions, thoughts,
and responses bas ed on Charles Darwin's Theory of Evolution Through
Natural Selection.
1.2 LANDMARKS IN THE HISTORY OF EVOLUTIONARY THINKING Evolution before Darwin :
Evolution refers to change over time. Change in life forms was postulated
by scientists to have occurred lo ng before Darwin published his classic
1859 book On the Origin of Species .
Jean Baptiste Lamarck (1744 –1829) was one of the first scientists to
recognize the study of life as a distinct science. Lamarck believed in two
major causes of species change: first , a natural tendency for each species
to progress toward a higher form and, second, the inheritance of acquired
characteristics.
Lamarck proposed that animals must struggle to survive and this struggle
causes their nerves to secrete a fluid that enlarges t he organs involved in
the struggle. Giraffes evolved long necks, he thought, through their
attempts to eat from higher and higher leaves.
Lamarck believed that the neck changes were passed down to succeeding
generations of giraffes, hence the phrase ―the i nheritance of acquired
characteristics.‖
Biologists before Darwin also noticed the variety of species, some with
astonishing structural similarities. Humans, chimpanzees, and orangutans,
for example, all have exactly five digits on each hand and foot. The wings
of birds are similar to the flippers of seals, perhaps suggesting that one
was modified from the other (Daly & Wilson, 1983). Comparisons among
these species suggested that life was not static, as some scientists and
theologians had argued. Further e vidence suggesting change over time
also came from the fossil record. Bones from older geological strata were
not the same as bones from more recent geological strata. These bones
would not be different, scientists reasoned, unless there had been a change
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4 Another source of evidence came from comparing the embryological
development of different species (Mayr, 1982). Biologists noticed that
such development was strikingly similar in species that otherwise seemed
very different from one another. An unusual loop -like pattern of arteries
close to the bronchial slits characterizes the embryos of mammals, birds,
and frogs. This evidence suggested, perhaps, that these species might have
come from the same ancestors millions of years a go. All these pieces of
evidence, present before 1859, suggested that life was not fixed or
unchanging. The biologists who believed that life forms changed over
time called themselves evolutionists.
Another key observation had been made by evolutionists be fore Darwin:
Many species possess characteristics that seem to have a purpose. The
porcupine‘s quills help it fend off predators. The turtle‘s shell helps to
protect its tender organs from the hostile forces of nature. The beaks of
many birds are designed to aid in cracking nuts. This apparent
functionality, so abundant in nature, required an explanation.
Missing from the evolutionists‘ accounts before Darwin, however, was a
theory to explain how change might take place over time and how such
seemingly purp oseful structures such as the giraffe‘s long neck and the
porcupine‘s sharp quills could have come about. A causal process to
explain these biological phenomena was needed. Charles Darwin provided
the theory of just such a process.
1.2.1 Darwin‟s Theory of Natural Selection :
Darwin not only wanted to explain why change takes place over time in
life forms, but also to account for the particular ways it proceeds. He
wanted to determine how new species emerge (hence the title of his book
On the Origin of Speci es), as well as why others vanish or go extinct.
Darwin wanted to explain why the component parts of animals —the long
necks of giraffes, the wings of birds, and the trunks of elephants —existed
in those particular forms. And he wanted to explain the apparen t purposive
quality of those forms, or why they seem to function to help organisms
accomplish specific tasks.
The answers to these puzzles can be traced to a voyage Darwin took after
graduating from Cambridge University. He travelled the world as a
natura list on a ship, the Beagle , for a five -year period, from 1831 to 1836.
During this voyage, he collected dozens of samples of birds and other
animals from the Galápagos Islands in the Pacific Ocean. On returning
from his voyage, he discovered that the Galáp agos finches, which he had
presumed were all of the same species, actually varied so much that they
constituted different species. Indeed, each island in the Galápagos had a
distinct species of finch.
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Figure 1.1: Finches on Galapagos Island (see the dif ference in beak
shape)
Source: https://www.thoughtco.com/charles -darwins -finches -1224472
Darwin determined that these different finches had a common ancestor but
had become different from each other because of the local ecological
conditions on each island. This geographic variation was pivotal to
Darwin‘s conclusion that species are not immutable but can change over
time.
What could account for why species change? Darwin struggled wi th
several different theories of the origins of change, but rejected all of them
because they failed to explain a critical fact: the existence of adaptations.
Darwin wanted to account for change, of course, but he also wanted to
account for why organisms a ppeared so well designed for their local
environments.
Darwin unearthed a key to the puzzle of adaptations when he found that
organisms exist in numbers far greater than can survive and reproduce.
The result must be a ―struggle for existence,‖ in which fav ourable
variations tend to be preserved and unfavourable ones tend to die out.
When this process is repeated generation after generation, the end result is
the formation of new adaptation.
Darwin‘s answer to all these puzzles of life was the theory of natural
selection and its three essential ingredients: variation, inheritance, and
differential reproductive success. First, organisms vary in all
sorts of ways, such as in wing length, trunk strength, bone mass, cell
structure, fighting abilit y, defensive ability, and social cunning. Variation
is essential for the process of evolution to operate —it provides the ―raw
materials‖ for evolution.
Second, only some of these variations are inherited —that is, passed down
reliably from parents to their offspring, who then pass them on to their
offspring down through the generations. Other variations, such as a wing
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6 offspring. Only those variations that are inherited play a role in the
evolutionary process.
The third critical ingredient of Darwin‘s theory is selection. Organisms
with some heritable variants leave more offspring because those attributes
help with the tasks of survival or reproduction. In an environment in
which the primary food source might be nut -bearing trees or bushes, some
finches with a particular shape of beak, for example, might be better able
to crack nuts and get at their meat than finches with other shapes of beaks.
More finches who have beaks better shaped for nut cracking survive than
those with beaks poorly shaped for nut cracking.
An organism can survive for many years, however, and still not pass on its
inherited qualities to future generations. To pass its inherited qualities to
future generations, it must rep roduce. Thus, differential reproductive
success , brought about by the possession of heritable variants that increase
or decrease an individual‘s chances of surviving and reproducing, is the
―bottom line‖ of evolution by natural selection. Differential repr oductive
success or failure is defined by reproductive success relative to others. The
characteristics of organisms that reproduce more than others, therefore, get
passed down to future generations at a relatively greater frequency.
Because survival is usu ally necessary for reproduction, it took on a critical
role in Darwin‘s theory of natural selection.
1.2.2 Darwin‟s Theory of Sexual Selection :
Darwin observed several inconsistencies that seemed to contradict his
theory of natural selection. First, he not iced structures that seemed to have
absolutely nothing to do with survival; the beautiful wings of peacocks
were a prime example. How could this strange structure possibly have
evolved? This was obviously costly to the peacock. Furthermore, it seems
like a n open invitation to predators.
Darwin also observed that in some species, the sexes differed dramatically
in size and structure. Why would the sexes differ so much, Darwin
wondered, when both males and female confront essentially the same
problems of sur vival, such as eating, fending off predators, and combating
diseases?
Darwin‘s answer to these apparent contradictions to the theory of natural
selection was to devise a second evolutionary theory: the theory of sexual
selection. In contrast to the theory of natural selection, which focused on
adaptations that have arisen as a consequence of successful survival, the
theory of sexual selection focused on adaptations that arose as a
consequence of successful mating. Darwin proposed two primary means
by which sexual selection could operate. The first is intrasexual
competition —competition between members of one sex, the outcomes of
which contributed to mating access to the other sex. The prototype of
intrasexual competition is two stags locking horns in combat. The victor
gains sexual access to a female either directly or through controlling
territory or resources desired by the female. The loser typically fails to
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7 Foundation of Evolutionary Psychology - I greater size, strength, or athletic ability, will be passed on to the next
generation because of the mating success of the victors.
Qualities that are linked with losing fail to get passed on. So evolution —
change over time —can occur simply as a consequence of intrasexual
competi tion.
The second means by which sexual selection could operate is intersexual
selection , or preferential mate choice. If members of one sex have some
consensus about the qualities that are desired in members of the opposite
sex, then individuals of the opp osite sex who possess those qualities will
be preferentially chosen as mates. Those who lack the desired qualities fail
to get mates. In this case, evolutionary change occurs simply because the
qualities that are desired in a mate increase in frequency wit h the passing
of each generation. If females prefer to mate with males who give them
gifts of food, for example, then males with qualities that lead to success in
acquiring food gifts will increase in frequency over time. Darwin called
the process of inter sexual selection female choice because he observed that
throughout the animal world, females of many species were discriminating
or choosy about whom they mated with.
Darwin‘s theory of sexual selection succeeded in explaining the anomalies
that worried hi m. The peacock‘s tail, for example, evolved because of the
process of intersexual selection: Peahens prefer to mate with males who
have the most brilliant and luminescent plumage. Males are often larger
than females in species in which males engage in phys ical combat with
other males for sexual access to females —a sex difference caused by the
process of intrasexual competition.
1.2.3 The Role of Natural Selection and Sexual Selection in
Evolutionary Theory :
Darwin‘s theories of natural and sexual selection are relatively simple to
describe, but many sources of confusion surround them even to this day.
First, natural selection and sexual selection are not the only causes of
evolutionary change. Some changes, for example, can occur because of a
process called genetic drift , which is defined as random changes in the
genetic makeup of a population. Random changes come about through
several processes, including mutation (a random hereditary change in the
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Figure 1. 2: Genetic drift
Source: https://www.anthromania.com/2021/07/27/genetic -drift/
Founder effects occur when a small portion of a population establishes a
new colony and the founders of the new colony are not genetically
representative of the original population. Imagine, for example, that the
200 colonizers who migrate to a new island happen by chance to include
an unusually large number of redheads. As the population on the island
grows, s ay, to 2,000 people, it will contain a larger proportion of redheads
than did the original population from which the colonizers came. Thus,
founder effects can produce evolutionary change —in this example, an
increase in genes coding for red hair.

Figure 1.3: Founder effect
Source: https://www.guyhowto.com/founder -effect/
A similar random change can occur through genetic bottlenecks , which
happen when a population shrinks, perhaps owing to a random catastrophe
such as an earthquake. The survivors of the random catastrophe carry only
a subset of the genes of the original population. In sum, although natural
selection is the primary cause of evolutionary change and the only known
cause of adaptations, it is not the only cause of evolutionary change.
Genetic drift —through mutations, founder effects, and genetic
bottlenecks —can also produce change in the genetic makeup of a
population.
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Figure1.4: Genetic bottleneck
Source: https://www.expii.com/t/what -is-the-bottleneck -effect -definition -
examples -10503
Second, evolution by natural selection is not forward -looking and is not
―intentional.‖ The giraffe does no t spy the juicy leaves stirring high in the
tree and ―evolve‖ a longer neck. Rather, those giraffes that, owing to an
inherited variant, happen to have longer necks have an advantage over
other giraffes in getting to those leaves. Hence they have a greater chance
of surviving and thus of passing on their slightly longer necks to their
offspring. Natural selection merely acts on variants that happen to exist.
Evolution is not intentional and cannot look into the future and foresee
distant needs.
Another crit ical feature of selection is that it is gradual , at least when
evaluated
Relative to the human life span. The short -necked ancestors of giraffes did
not evolve long necks overnight or even over the course of a few
generations. It has taken dozens, hundreds , thousands, and in some cases
millions of generations for the process of selection to gradually shape the
organic mechanisms, we see today. Of course, some changes occur
extremely slowly, others more rapidly. And there can be long periods of
no change, followed by a relatively sudden change, a phenomenon known
as ―punctuated equilibrium‖
(Gould & Eldredge, 1977). But even these ―rapid‖ changes occur in tiny
increments in each generation and take hundreds or thousands of
generations to occur.
Darwin‘s theor y of natural selection offered a powerful explanation for
many baffling aspects of life. It explained the origin of new species. It
accounted for the modification of organic structures over time. It
accounted for the apparent purposive quality of the comp onent parts of
those structures —that is, they seemed ―designed‖ to serve particular
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10 For the first time, each species was viewed as being connected with all
other species through a common ancestry. Hum an beings and
chimpanzees, for example, share more than 98 percent of each other‘s
DNA and shared a common ancestor roughly 6 or 7 million years ago
(Wrangham & Peterson, 1996). Another important fact was that many
human genes turned out to have counterpar t genes in a transparent worm
called Caenorhabditis elegans. They are highly similar in chemical
structure, suggesting that humans and this worm evolved from a distant
common ancestor (Wade, 1997). In short, Darwin‘s theory made it
possible to locate human s in the grand tree of life, showing their place in
nature and their links with all other living creatures.
Objection to Darwin‟s Theory :
Darwin‘s theory of natural selection created lot of controversy. Royalties
did not like the idea that their ancestors were apes. Even biologists at the
time were highly sceptical of Darwin‘s theory of natural selection. One
objection was that Darwinian evolution lacked a proper theory of
inheritance. Darwin himself preferred a “blending” theory of
inheritance , in which of fspring are mixtures of their parents, much like
pink paint is a mixture of red paint and white paint. This theory of
inheritance is now known to be wrong, so early critics were correct in the
objection that the theory of natural selection lacked a solid t heory of
heredity.
Another objection was that some biologists could not imagine how the
early stages of wing help a bird, if a partial wing is insufficient for flight?
How could a partial eye help a reptile, if a partial eye is insufficient for
sight?
Darwin‘s theory of natural selection requires that each and every step in
the gradual evolution of an adaptation be advantageous in the currency of
reproduction. Thus, partial wings and eyes must yield an adaptive
advantage, even before they evolve into fully developed wings and eyes.
A third objection came from religious creationists, many of whom viewed
species as immutable (unchanging) and created by a deity rather than by
the gradual process of evolution by selection.
The controversy continues to this day . Although Darwin‘s theory of
evolution, with some important modifications, is the unifying and nearly
universally accepted theory within the biological sciences, its application
to humans still meets some resistance.
Genes and Particulate Inheritance :
When Darwin published On the Origin of Species , he did not know the
nature of the mechanism by which inheritance occurred. An Austrian
named Gregor Mendel showed that inheritance was ―particulate,‖ and not
blended. That is, the qualities of the parents are n ot blended with each
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11 Foundation of Evolutionary Psychology - I called genes. Furthermore, parents must be born with the genes they pass
on; genes cannot be acquired by experience.
Mendel‘s discovery that inheritance is p articulate, which he demonstrated
by crossbreeding different strains of pea plants, remained unknown to
most of the scientific community for some thirty years.
The Modern view discarded a number of misconceptions in biology,
including the blending theory of inheritance. It confirmed the importance
of Darwin‘s theory of natural selection, but put it on a firmer footing with
a well -articulated understanding of the nature of inheritance.
1.3 MOVEMENTS AND CONTROVERSIES IN EVOLUTIONARY THINKING The Ethology Mo vement :
We can easily see how a turtle‘s shell is an adaptation for protection and a
bird‘s wings an adaptation for flight. We recognize similarities between
ourselves and chimpanzees, and so most people find it relatively easy to
believe that human beings and chimps have a common ancestry. The
paleontological record of skulls reveals that change has taken place over
time. The evolution of behaviour, however, has historically been more
difficult for scientists and laypeople to imagine. Behaviour, after all,
leaves no fossils, at least not directly.
Darwin thought his theory of natural selection to be just as applicable to
behaviour, including social behaviour, as to physical structures. Several
lines of evidence support this view. First, all behaviour requir es
underlying physical structures. Bipedal locomotion is a behaviour, for
example, and requires the physical structures of two legs and muscles to
support those legs. Second, species can be bred for certain behavioural
characteristics using the principle o f selection. Dogs, for example, can be
bred (artificial selection) for aggressiveness or passivity.
These lines of evidence all point to the conclusion that behaviour is not
exempt from the sculpting hand of evolution. The first major discipline to
form ar ound the study of behaviour from an evolutionary perspective was
the field of ethology.
The ethology movement was in part a reaction to the extreme
environmentalism in U.S. psychology. Ethologists were interested in four
key issues, which have become known as the four ―whys‖ of behaviour
advanced by one of the founders of ethology, Nikolaas Tinbergen (1951):
(1) the immediate influences on behaviour (e.g., the movement of the
mother);
(2) the developmental influences on behaviour (e.g., the events during the
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12 (3) the function of behaviour, or the ―adaptive purpose‖ it fulfils (e.g.,
keeping the baby duck close to the mother, which helps it to survive),
and
(4) the Evolutionary or phylogenetic origins of behaviour (e.g ., what
sequence of evolutionary events led to the origins of an imprinting
mechanism in the duck).
The ethology movement went a long way toward orienting biologists to
focus on the importance of adaptation. Ethology also forced psychologists
to reconsider the role of biology in the study of human behaviour. This set
the stage for an important scientific revolution, brought about by a
fundamental reformulation of Darwin‘s theory of natural selection.
The Inclusive Fitness Revolution :
In the early 1960s, Wil liam D. Hamilton was working on his doctoral
dissertation at University College, London. Hamilton proposed a new
revision of evolutionary theory, which he termed ―inclusive fitness
theory.‖ Hamilton‘s theory sparked a revolution that transformed the
entire field of biology. Hamilton reasoned that classical fitness —the
measure of an individual‘s direct reproductive success in passing on genes
through the production of offspring —was too narrow to describe the
process of evolution by selection. He theorized th at natural selection
favours characteristics that cause an organism‘s genes to be passed on,
regardless of whether the organism produces offspring directly.
Parental care —investing in one‘s own children —was reinterpreted as
merely a special case of caring for kin who carry copies of parent‘s genes
in their bodies. An organism can also increase the reproduction of its
genes by helping brothers, sisters, nieces, or nephews to survive and
reproduce. All these relatives have some probability of carrying copies of
the organism‘s genes. Hamilton‘s genius was in the recognition that the
definition of classical fitness was too narrow and should be broadened to
be inclusive fitness.
Technically, inclusive fitness is not a property of an individual or an
organism but rather a property of its actions or effects. Thus, inclusive
fitness can be viewed as the sum of an individual‘s own reproductive
success (classical fitness) plus the effects the individual‘s actions have on
the reproductive success of his or her genetic r elatives.
The key point is that the gene is the fundamental unit of inheritance, the
unit that is passed on intact in the process of reproduction. Genes
producing effects that increase their own replicative success will replace
other genes, producing evol ution over time. Adaptations are selected and
evolve because they promote inclusive fitness.
Thinking about selection from the perspective of the gene offered a wealth
of insights unknown in Darwin‘s day (Buss, 2009). The theory of
inclusive fitness has se veral consequences for how we think about the munotes.in

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13 Foundation of Evolutionary Psychology - I psychology of the family, altruism, helping, the formation of groups, and
even aggression.
Clarifying Adaptation and Natural Selection :
Williams (1966) challenged the prevailing thinking of group selection , the
notion that adaptations evolved for the benefit of the group through the
differential survival and reproduction of groups (Wynne -Edwards, 1962),
as opposed to benefit of the gene and arising through the differential
reproduction of genes.
According to the theory of group selection, an animal might limit its
personal reproduction to keep the population low, thus avoiding the
destruction of the food base on which the population relied. According to
group selection theory, only species that possessed characte ristics
beneficial to their group survived. Those that acted more selfishly perished
because of the over -exploitation of the critical food resources on which the
species relied.
Williams argued that group selection, although theoretically possible, was
likely to be a weak force in evolution, for the following reason. Imagine a
bird species with two types of individuals —one that sacrifices itself by
committing suicide so as not to deplete its food resources and another that
selfishly continues to eat the foo d, even when supplies are low. In the next
generation, which type is likely to have descendants? The answer is that
the suicidal birds will have died out and failed to reproduce, whereas those
who refused to sacrifice themselves for the group will have sur vived and
left descendants.
Williams‘s second contribution was in translating Hamilton‘s theory of
inclusive fitness into clear prose that could be comprehended by everyone.
To mention one prominent example, inclusive fitness theory partially
solved the ― problem of altruism‖: How could altruism evolve —incurring
reproductive costs to oneself to benefit the reproduction of others —if
evolution favours genes that have the effect of self -replication? Inclusive
fitness theory solved this problem (in part) becaus e altruism could evolve
if the recipients of help were one‘s genetic relatives.
Parents, for example, might sacrifice their own lives to save the lives of
their children, who carry copies of the parents‘ genes within them. The
same logic applies to making sacrifices for other genetic relatives, such as
sisters or cousins. The benefit to one‘s relatives in fitness currencies must
be greater than the costs to the self. If this condition is satisfied, then kin
altruism can evolve. In later chapters, we review evidence showing that
genetic relatedness is indeed a powerful predictor of helping among
humans.
The third contribution of Adaptation and Natural Selection was Williams‘s
careful analysis of adaptation, which he referred to as ―an onerous
concept.‖ Adapta tions may be defined as evolved solutions to specific
problems that contribute either directly or indirectly to successful
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14 solve the survival problem of thermal regulation. Taste prefere nces may
be adaptations that guide the successful consumption of nutritious food.
Mate preferences may be adaptations that guide the successful selection of
fertile mates.
The problem is how to determine which attributes of organisms are
adaptations. Willi ams established several standards for invoking
adaptation and believed that it should be invoked only when necessary to
explain the phenomenon at hand. When a flying fish leaps out of a wave
and falls back into the water, for example, we do not have to inv oke an
adaptation for ―getting back to water.‖ This behaviour is explained more
simply by the physical law of gravity.
Trivers‟s Seminal Theories :
In the late 1960s and early 1970s Robert Trivers, studied Williams‘s 1966
book on adaptation. Trivers contrib uted three seminal papers, all published
in the early 1970s. The first was the theory of reciprocal altruism
among nonkin —the conditions under which mutually beneficial
exchange relationships or transactions could evolve (Trivers, 1971).
The second was parental investment theory , which provided a powerful
statement of the conditions under which sexual selection would occur for
each sex (1972).
The third was the theory of parent –offspring conflict —the notion that
even parents and their progeny will get int o predictable sorts of conflicts
because they share only 50 percent of their genes (1974). Parents may try
to wean children before the children want to be weaned, for example, in
order to free up resources to invest in other children. More generally, what
might be optimal for a child (e.g., securing a larger share of parental
resources) might not be optimal for the parents (e.g., distributing resources
more equally across children).
The Socio -biology Controversy :
Eleven years after Hamilton‘s paper on inclu sive fitness was published, a
Harvard biologist named Edward O. Wilson wrote a book ‗ Sociobiology:
The New Synthesis’. It offered a synthesis of cellular biology, integrative
neurophysiology, ethology, comparative psychology, population biology,
and behavi oural ecology. It also examined species from ants to humans,
proclaiming that the same fundamental explanatory principles could be
applied to all.
Sociobiology is not generally regarded as containing fundamentally new
theoretical contributions to evolution ary theory. It actually synthesized all
the previous work under one umbrella.
The chapter on humans, the last in Wilson‘s book created the most
controversy. His work sparked attacks from Marxists, radicals,
creationists, other scientists, and even members of his own department at
Harvard. Part of the controversy stemmed from the nature of Wilson‘s munotes.in

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15 Foundation of Evolutionary Psychology - I claims. He asserted that sociobiology would ―cannibalize psychology,‖
which was not greeted warmly by most psychologists. Further, he
speculated that many importa nt human phenomena, such as culture,
religion, ethics, and even aesthetics, would ultimately be explained by the
new synthesis. These assertions strongly contradicted the dominant
theories in the social sciences. Culture, learning, socialization, rationali ty,
and consciousness, not evolutionary biology, were presumed by most
social scientists to explain human behaviour.
Despite Wilson‘s claims for a new synthesis that would explain human
nature, he had little empirical evidence on humans to support his view s.
The bulk of the scientific evidence came from nonhuman animals. Most
social scientists could not see what ants and fruit flies had to do with
people. Furthermore, the tremendous resistance to Wilson‘s inclusion of
humans within the purview of evolutiona ry theory was based on several
common misunderstandings. We will highlight some of the
misunderstandings here.
1.4 COMMON MISUNDERSTANDINGS ABOUT EVOLUTIONARY THEORY The theory of evolution by selection generates a number of common
misunderstandings (Conf er et al., 2010).
Misunderstanding 1: Human Behaviour Is Genetically Determined
Genetic determinism is the doctrine that argues that behaviour is
controlled exclusively by genes, with little or no role for environmental
influence. Much of the resistance t o applying evolutionary theory to the
understanding of human behaviour stems from the misconception that
evolutionary theory implies genetic determinism. Contrary to this
misunderstanding, evolutionary theory represents a truly interactionist
framework.
Human behaviour cannot occur without two ingredients: (1) evolved
adaptations and (2) environmental input that triggers the development and
activation of these adaptations.
Notions of genetic determinism —behaviours caused by genes without
input or influence from the environment —are simply false. They are in no
way implied by the evolutionary theory or by evolutionary psychology.
Misunderstanding 2: If It‟s Evolutionary, We Cannot Change It :
A second misunderstanding is that evolutionary theory implies that hu man
behaviour is impervious to change. Consider the simple example of
calluses again. Humans can and do create physical environments that are
relatively free of friction. These friction -free environments mean that we
have designed change —a change that prev ents the activation of the
underlying callus -producing mechanisms. Knowledge of these
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16 us the power to decrease callus production. Knowledge of this mechanism,
however, allows for th e possibility of change.
More knowledge about our evolved psychology, however, gives us more
power to change.
Misunderstanding 3: Current Mechanisms Are Optimally Designed :
The concept of adaptation, the notion that mechanisms have evolved
functions, has led to many outstanding discoveries over the past century
(Dawkins, 1982). This does not mean, however, that the current collection
of adaptive mechanisms that make up humans is in any way ―optimally
designed.‖
One constraint on optimal design is evolutio nary time lags. Evolution
refers to change over time. Each change in the environment brings new
selection pressures. Because evolutionary change occurs slowly, requiring
hundreds or thousands of generations of recurrent selection pressure,
existing humans are necessarily designed for the previous environments of
which they are a product. Stated differently, we carry around a Stone Age
brain in a modern environment. In other words, ―we are walking archives
of ancestral wisdom‖ (Cronin, 1991). A strong taste preference for fat and
sugar, adaptive in a past environment of scarce food resources, now leads
to clogged arteries, Type 2 diabetes, and heart attacks. The lag in time
between the environment that fashioned Our mechanisms (the hunter -
gatherer past that f ormed much of our selective environment) and today‘s
environment means that our some of our existing evolved mechanisms
may not be optimally designed for the current environment.
All adaptations carry costs. Selection favours a mechanism when its
benefits outweigh the costs relative to other designs existent at the time.
Humans have evolved mechanisms that are reasonably good at solving
adaptive problems efficiently, but they are not designed as optimally as
they might be if costs were not a constraint. Evo lutionary time lags and the
costs of adaptations are just two of the many reasons why adaptations are
not optimally designed (Williams, 1992).
In summary, part of the resistance to the application of evolutionary theory
to humans are based on several commo n misconceptions. Contrary to
these misconceptions, evolutionary theory does not imply genetic
determinism. It does not imply that we are powerless to change things. It
does not mean that our existing adaptations are optimally designed. With
these common m isunderstandings about evolutionary theory clarified, let‘s
turn to an examination of the milestones in human evolutionary history.
1.5 ORIGINS OF HUMAN NATURE, EVOLUTIONARY GAME THEORY Three Theories of the Origins of Complex Adaptive Mechanism :
In the p ast century, three major theories have been proposed to account for
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17 Foundation of Evolutionary Psychology - I Creationism Theory :
One theory is creationism, or ―intelligent design,‖ the idea that a supreme
deity created all of the plants and animals, from the largest wh ales to the
smallest plankton in the ocean, from the simple single celled amoebas to
the complex human brain. Creationism is not viewed as a ―scientific
theory‖ for three reasons.
 First, it cannot be tested because specific empirical predictions do not
follow from its major premise. Whatever exists does so simply
because the Supreme Being has created it.
 Second , creationism has not guided researchers to any new scientific
discoveries.
 Third , creationism has not proved useful as a scientific explanation
for already discovered organic mechanisms. Creationism, therefore, is
a matter of religion and belief, not a matter of science. It cannot be
proved to be false, but it has not proven useful as a predictive or an
explanatory theory (Kennair, 2003).
Seeding Th eory :
A second theory is seeding theory. According to seeding theorists, life did
not originate on earth. In one version of this theory, the seeds of life
arrived on earth via a meteorite.
In a second version of seeding theory, extraterrestrial intelligent beings
came down from other planets or galaxies and planted the seeds of life on
earth. Regardless of the origins of the seeds, however, evolution by natural
selection presumably took over, and the seeds eventually evolved into
humans and the other life f orms observed today.
Seeding theory is in principle testable. We can study meteorites for signs
of life, which would lend plausibility to the theory that life originated
elsewhere. We can scour the earth for signs of extraterrestrial landings.
We can look for evidence of life forms that could not have originated on
earth. Seeding theory, however, runs into two problems.
 First , there is currently no solid scientific evidence on earth that such
―seedings‖ have taken place.
 Second, seeding theory has not led t o any new scientific discoveries,
nor has it explained any existing scientific puzzles. Most important,
however, seeding theory simply pushes the causal explanation for life
forms back in time. If the earth was really seeded by extraterrestrial
beings, wha t causal processes led to the origins of these intelligent
beings?
Evolution by Natural Selection :
The third theory is evolution by natural selection. Although evolution by
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18 confirme d so many times —and never disconfirmed —that it is viewed by
most biologists as a fact (Alcock, 2013). The components of its
operation —differential reproduction due to inherited design differences —
have been shown to work in both the laboratory and the wild. The
differing sizes of the beaks of finches on different islands in the
Galápagos, for example, have evolved to correspond to the size of the
seeds prevalent on each island (Grant, 1991). Larger beaks are needed
when the seeds are large; smaller beaks are better when the seeds are tiny.
The theory of natural selection has many virtues that scientists seek in a
scientific theory: (1) it explains known facts; (2) it leads to new
predictions; and (3) it provides guidance to important domains of scientific
inquiry.
So among the three theories —creationism, seeding theory, and natural
selection — there is no real contest. Evolution by natural selection is the
only known scientific theory that can explain the astonishing diversity of
life we see around us today. An d it is the only known scientific theory that
has the power to account for the origins and structure of complex adaptive
mechanisms —from callus -producing mechanisms to large brains — that
define human nature.
1.6 THE THREE PRODUCTS OF EVOLUTION There are th ree products of the evolutionary process —adaptations, by -
products (or concomitants) of adaptation, and random effects (or noise). Product Brief Definition Adaptation s Inherited and reliably developing characteristics that came into existence through natural selection because they helped to solve problems of survival or reproduction better than alternative designs existing in the population during the period of their evolution; example: umbilical cord By-products Characteristics that do not solve adaptive problems
and do not have
functional design; they are ―carried along‖ with
characteristics that do have functional design because
they happen to be coupled with those adaptations;
example: belly button Noise Random effects produced by forces such as chance mutations, sudden and unprecedented changes in the environment, or chance effects during development; example: particular shape of a person‘s belly button Table 1.1 Three Products of the Evolutionary Process munotes.in

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19 Foundation of Evolutionary Psychology - I Source: Evolutionary Psychology: T he New Science of the Mind by
David Buss, 5th Ed.
An adaptation may be defined as an inherited and reliably developing
characteristic that came into existence through natural selection because it
helped to solve a problem of survival or reproduction during the period of
its evolution (Tooby & Cosmides, 1992).
An adaptation must have genes ―for‖ that adaptation. Those genes are
required for the passage of the adaptation from parents to children; hence,
adaptations have a genetic basis.
An adaptation must de velop reliably among species members in all
―normal‖ environments.
Adaptations are fashioned by the process of selection. Selection acts as a
sieve in each generation, filtering out the many features that do not
contribute to propagation and letting throu gh those that do (Dawkins,
1996). This sieving process recurs generation after generation so that each
new generation is a bit different from its parent generation. Those
characteristics that make it through the filtering process in each generation
do so b ecause they contribute to the solution of an adaptive problem of
either survival or reproduction better than alternative (competing) designs
existing in the population.
The function of an adaptation refers to the adaptive problem it evolved to
solve, that is, precisely how it contributes to survival or reproduction. The
function of an adaptation is typically identified and confirmed by the
evidence of ―special design,‖ whereby the components or ―design
features‖ all contribute in a precise manner to solve a particular adaptive
problem.
Each adaptation has its own period of evolution. Initially, a mutation, a
copying error in a piece of DNA, occurs in a single individual. Although
most mutations hinder survival or reproduction, some, by chance alone,
end up helping the organism survive and reproduce.
If the mutation is helpful enough to give the organism a reproductive
advantage over other members of the population, it will be passed down to
the next generation in greater numbers. In the next generation, the refore,
more individuals possess the characteristic that was initially a mutation in
a single person. Over many generations, if it continues to be successful,
the mutation will spread to the entire population, so every member of the
species will have it.
Although adaptations are the primary products of evolution, the
evolutionary process also produces by -products of adaptations. By -
products are characteristics that do not solve adaptive problems and do not
have a functional design. They are ―carried along‖ with characteristics that
do have functional design because they happen to be coupled with those
adaptations, just as the heat from a lightbulb is a by -product of design for
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20 Consider the human belly button. There is no evidence that the belly
button , per se, helps humans survive or reproduce. A belly button is not
good for catching food, detecting predators, avoiding snakes, finding good
habitats, or choosing mates. It does not seem to be directly or indirectly
involved in the solution to an adaptive problem. Rather, the belly button is
a by-product of something that is an adaptation —namely, the umbilical
cord that provided food to the growing foetus. The hypothesis that
something is a by -product of an adaptation, therefore, requires identifying
the a daptation of which it is a by -product and the reason why its existence
is associated with that adaptation.
Belly buttons are not adaptations —they are not good for catching prey or
deterring predators. Rather, they are by -products of something that was an
adaptation —the formerly functional umbilical cord by which a foetus
obtained nutrients from its mother.
The third and final product of the evolutionary process is noise or
random effects. Random effects can be produced by forces such as
mutations, sudden an d unprecedented changes in the environment, or
accidents during development. These random effects sometimes harm the
smooth functioning of an organism, much as throwing sand into a machine
or spilling scalding coffee onto the hard drive of your computer ma y ruin
its functional operation. Some random effects are neutral —they neither
contribute to nor detract from adaptive functioning —and some are
beneficial to an organism. Noise is distinguished from by -products in that
it is not linked to the adaptive aspec ts of design features but rather is
independent of such features.
In summary, the evolutionary process produces three products —
adaptations, by -products of adaptations, and random effects. Evolutionary
scientists differ in their estimates of the relative si zes of these three
categories of products. Some believe that even uniquely human qualities,
such as language, are merely incidental by -products of our large brains
(Gould, 1991). Others see overwhelming evidence that human language is
an adaptation (Pinker , 1994).
1.7 LEVELS OF EVOLUTIONARY ANALYSIS IN EVOLUTIONARY PSYCHOLOGY One of the essential features of any science is the formulation of
hypotheses. In the case of evolutionary psychology, the nature of
hypotheses typically centres on adaptive problems and their solutions.
More specifically, it centres on the adaptive problems faced by our
ancestors and on the adaptive psychological solutions to those problems.
General Evolutionary Theory :
The first level of analysis is general evolutionary theory. In i ts modern
form, evolution by natural selection is understood from the ―gene‘s eye‖
perspective —differential gene replication is the engine of the evolutionary munotes.in

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21 Foundation of Evolutionary Psychology - I process by which adaptations are formed (Cronin, 2005; Dawkins, 1982,
1989; Hamilton, 1964; Willi ams, 1966).
Natural selection, however, is the only known fundamental causal process
capable of creating complex functional design and hence will be treated
here as the most general level in the hierarchy of evolutionary theorizing.
At this general level, even though we talk about evolutionary ―theory,‖ it
is widely accepted by biological scientists as fact. Most of the research in
evolutionary psychology proceeds from the assumption that evolutionary
theory is correct, but the research does not test that assumption directly.
There are observations that could, in principle, falsify general evolutionary
theory: if scientists observed complex life forms that were created in time
periods too short for natural selection to have operated (e.g., in seven
days); i f scientists discovered adaptations that functioned solely for the
benefit of other species; if scientists discovered adaptations that
functioned for the benefit of same -sex competitors; and so on (Darwin,
1859; Mayr, 1982; Williams, 1966). No such phenome na have ever been
documented.
Middle -Level Evolutionary Theories :
Moving one level down we find middle -level theories such as Trivers‘s
theory of parental investment and sexual selection. Let‘s examine one
theory —Trivers‘s theory of parental investment as the driving force
behind sexual selection. This theory, an elaboration of Darwin‘s theory of
sexual selection (1871), provided one of the key ingredients for predicting
the operation of mate choice and intra -sexual competition (competition
between members of the same sex). Trivers argued that the sex that invests
more resources in its offspring (often, but not always, the female) will
evolve to be more choosy or discriminating in selecting a mate. The sex
that invests fewer resources in its offspring, in c ontrast, will evolve to be
less choosy and more competitive with members of their own sex for
sexual access to the valuable, high -investing opposite sex.
Middle -level theories must be compatible with general evolutionary
theory, but they must stand or fall on their own merits.
Specific Evolutionary Hypotheses :
Let‘s now examine the specific evolutionary hypotheses. One hypothesis
that has been advanced for humans, for example, is that women have
evolved specific preferences for men who have resources to off er (Buss,
1989; Symons, 1979). The logic is as follows. First, because women invest
heavily in children, they have evolved to be choosy when they pick
mates —the standard prediction from parental investment theory. Second,
the content of women‘s choices sho uld reflect whatever has historically
increased the survival and reproduction of them and their children.
Therefore, women are hypothesized to have evolved mate preferences for
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22 their chi ldren. This is an evolutionary psychological hypothesis because it
proposes the existence of a specific psychological mechanism —a desire —
that is designed to solve a specific human adaptive problem, namely
securing a mate who appears capable of investing in children.
This specific evolutionary psychological hypothesis can be tested
empirically. Scientists can study women across a wide variety of cultures
and determine whether they in fact prefer men who are able and willing to
contribute resources to them an d their children.
On the basis of the hypothesis that women prefer men who have resources
to offer, we could make the following predictions: (1) Women will value
in men specific qualities known to be linked with the acquisition of
resources such as social status, intelligence, and somewhat older age; (2)
in a singles bar, women‘s attention, as measured by eye gaze, will be
drawn more to men who appear to have resources than to men who do not;
and (3) women whose husbands fail to provide economic resources w ill be
more likely to divorce them than women whose husbands do contribute
economic resources.
All of these predictions follow from the hypothesis that women have a
specific evolved preference for men with resources. The value of the
hypothesis rests with the scientific tests of predictions derived from it. If
the predictions fail —if women are shown not to desire personality
characteristics known to be linked with resource acquisition, do not gaze
more at men with resources in singles bars, and are not more likely to
divorce husbands who fail to provide resources —then the hypothesis will
not be supported. If the predictions succeed, then the hypothesis is
supported.
Evaluation of evolutionary formulations rests with the cumulative weight
of the evidence, and not necessarily with any single prediction.
Evolutionary hypotheses, when formulated precisely, are highly testable
and capable of being falsified when the evidence fails to support
predictions derived from them (Ketelaar & Ellis, 2000).

Table 1.2: Thre e levels of Evolutionary Hypotheses munotes.in

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23 Foundation of Evolutionary Psychology - I Source: Evolutionary Psychology: The New Science of the Mind by
David Buss, 5th Ed.
1.8 TWO STRATEGIES FOR GENERATING AND TESTING EVOLUTIONARY HYPOTHESES There are two strategies for generating and testing evolutionary
hypotheses. One strategy is called the top -down or theory driven approach
to hypothesis generation. One can start at the top with general
evolutionary theory and derive hypotheses. For example, we could predict
solely based on inclusive fitness theory that humans will help close
genetic relatives more than they will distant genetic relatives. Or we could
generate a hypothesis based on Trivers‘s middle -level theory of parental
investment. Either way, the derivations flow downward going from the
general to the specific.
Top-down strategy :
The top-down strategy illustrates one way in which theories can be
extraordinarily useful. Theories provide a set of working premises from
which specific hypotheses can be generated. They also furnish a
framework for guiding r esearchers to important domains of inquiry such
as investing in kin or children.
Bottom - up strategy :
There is a second strategy for generating evolutionary psychological
hypotheses called as bottom -up strategy. Instead of starting with a theory,
we can st art with an observation. Once the observation is made about the
existence of a phenomenon, we can then proceed in a bottom -up fashion
and generate a hypothesis about its function. Because humans are keen
perceivers of other people, they generally notice th ings even without a
formal theory to direct attention to them. For example, most people don‘t
need a theory to tell them that humans communicate through spoken
language, walk upright on two legs, and sometimes wage war on other
groups. There is nothing in general evolutionary theory that would have
generated the hypothesis that language, bipedal locomotion, or group -on- Strategy 1: Theory-Driven or ―Top – down‖ Strategy Strategy 2: Observation-Driven or ―Bottom-Up‖ Strategy Step 1: Derive Hypothesis from Existing Theory Example: From parental investment theory, we can derive the hypothesis that because women have a greater obligatory investment in offspring than men, women will tend to be more choosy or discriminating in their selection of a mate. Step 1: Develop Hypothesis about Adaptive Function Based on a Known Observation: Example: A. Observation: Men seem to give higher priority than women to physical appearance in the selection of a mate. B. Hypothesis: Women‘s physical appearance provided ancestral men with cues to fertility. Step 2: Test Predictions Based on Hypothesis Step 2: Test Predictions Based on Hypothesis munotes.in

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24 Example: Conduct an experiment to test the prediction that a woman will impose a longer delay and more stringent standards before consenting to sex to evaluate a man‘s quality and commitment. Example: Conduct experiments to determine whether men‘s standards of attractiveness are closely based on cues to a woman‘s fertility. Step 2: Test Predictions Based on Hypothesis Example: Conduct an experiment to test the prediction that a woman will impose a longer delay and more stringent standards before consenting to sex to Step 2: Test Predictions Based on Hypothesis Example: Conduct experiments to determine whether men‘s standards of attractiveness are closely based on cues to a woman‘s fertility. Step 3: Evaluate Whether Empirical Results Confirm Predictions Example: Women impose longer delays and impose more stringent standards than men before consenting to sex (Buss & Schmitt, 1993; Kennair, Schmitt, Fjeldavli, & Harlem, 2009). Step 3: Evaluate Whether Empirical Results Confirm Predictions Example: Men find a low waist-to-hip ratio, a known fertility correlate, attractive (Dixon, Grimshaw, Linklater, & Dixon, 2010; Singh, 1993). Table 1.3 Two Strategies of Generating and Testing Evolutionary
Hypotheses
Source : Evolutionary Psychology: The New Science of the Mind by
David Buss, 5th Ed.
1.9 EVOLUTIONARY GAME THEORY Evolutionary game theory (EGT) is the application of game theory to
evolving populations in biology. It defines a framework of contests,
strategies, and analytics into which Darwinian competition can be
modelled. It originated in 1973 with John Maynard Smith and George R.
Price's formalisation of contests, analysed as strategies, and the
mathematical criteria that can be used to predict the results of competing
strategies.
Evolutionary game theory has helped to explain the basis of altruistic
behaviours in Darwinian evolution. It has in turn become of interest to
econom ists, sociologists, anthropologists, and philosophers.
Evolutionary game theory started with the problem of how to explain
ritualized animal behaviour in a conflict situation; "why are animals so
'gentlemanly or ladylike' in contests for resources?" The et hologists Niko
Tinbergen and Konrad Lorenz proposed that such behaviour exists for the
benefit of the species. John Maynard Smith considered that incompatible
with Darwinian thought, where selection occurs at an individual level, so
self-interest is reward ed while seeking the common good is not. Maynard
Smith, a mathematical biologist, turned to game theory as suggested by
George Price.
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25 Foundation of Evolutionary Psychology - I Adapting game theory to evolutionary games :
Maynard Smith realised that an evolutionary version of game theory does
not re quire players to act rationally —– only that they have a strategy. The
results of a game shows how good that strategy was, just as evolution tests
alternative strategies for the ability to survive and reproduce. In biology,
strategies are genetically inher ited traits that control an individual's action,
analogous with computer programs. The success of a strategy is
determined by how good the strategy is in the presence of competing
strategies (including itself), and of the frequency with which those
strateg ies are used. Maynard Smith described his work in his book
Evolution and the Theory of Games.
Prisoner‟s dilemma and reciprocal altruism :
There is a branch of mathematics that deals with the decisions that people
are predicted to make depending on the str ategies of others. It‘s called
game theory.
The whole idea about game theory is that it examines problems the world
presents in both simplified and universal ways. One of the main aims of
game theory is to find a solution to a problem which, given what
everybody else is doing, cannot be bettered. This accepted solution is
known as the Nash equilibrium after the Nobel -prize -winning Princeton
mathematician John Nash, about whom the film A Beautiful Mind was
made.
Having been developed by economists to predi ct what people are likely to
do with investment decisions, John Maynard -Smith introduced game
theory into animal behaviour to explain the relationship between
behaviour and evolution.
Subsequently it has been developed to help understand the evolutionary
basis of human decision making. But what, you might ask, has this got to
do with reciprocal altruism? One particular hypothetical scenario that
game theory has been applied to solving is called ‗prisoner‘s dilemma‘. As
you‘ll see, it may be likened to the problems surrounding reciprocal
altruism.
In prisoner‘s dilemma two criminal suspects are arrested by the police and
placed in separate questioning cells. Each is told that if they implicate the
other, they will be rewarded and set free while the other wil l receive a
harsh sentence. If, however, neither talks then both will receive a light
sentence.
In game theory terminology implicating the other is called „defection‟ and
refusing to talk is called „cooperation‟ . The outcome or payoff for each
player is ge nerally symbolised by one of four symbols:
T is the temptation to defect;
R is the reward each receives if they cooperate; munotes.in

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26 P is the punishment they receive if both defect; and
S is the sucker‟s payoff – that is, if you cooperate when your partner
has defe cted.
In this set -up it is important that the payoff decreases from T through R
and P to S. It is also necessary that the payoff for mutual cooperation is
greater than the average payoff for cooperation and defection – otherwise
there is no real incentive to cooperate.
Mathematically we can express the payoff in prisoner‘s dilemma as
T > R > P > S.
In practice the game is played for points – providing values for each of
these will help. Typically, the following values are given:
T = 5; R = 3; P = 1; S = 0
We can represent the four possible outcomes in a ‗payoff matrix‘ below.
Note that the points gained are given for Player B in the above example,
not Player A (although in the case of mutual defection or cooperation both
players will have equal scores). Cooperate Defect Player B Cooperate R= 3 S= 0 Reward for Sucker‘s payoff Mutual cooperation Defect T= 5 P= 1 Temptation to Punishment for Defect mutual defection Table 1.4: The prisoner‟s dilemma – „payoff matrix‟ showing four
possible outcomes
Source: Wikipedia
Now here‘s the dilemma. Both players should realise that rationally they
should defect – but this makes each worse off than if they both cooperated.
But why can we expect that each would defect? Think the following:
If you are playing this game, you must consider what your partner might
do. If your partner cooperates, then by defecting you will ga in 5 points; if
your partner defects then you will have to defect in order to gain the 1
point for punishment rather than the 0 which is a sucker‘s payoff.
The dilemma boils down to the fact that you do not know what your
partner is going to do. Prisoner‟ s dilemma suggests that people should
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27 Foundation of Evolutionary Psychology - I At this point you might be thinking that prisoner‘s dilemma sounds like a
little game which has nothing to do with real social behaviour. However,
as Matt Ridley puts it, prisoner‘s dilemmas are all aro und us: Broadly
speaking any situation in which you are tempted to do something but knew
it would be a great mistake if everybody did the same thing, is likely to be
a prisoner‘s dilemma. (Ridley, 1996)
Thus, deciding whether or not to buy a round of drin ks, deciding whether
or not to repay the favour of babysitting, considering the tipping of a
waiter, and perhaps most importantly of all, deciding whether or not to
remain faithful in a relationship – these may all be thought of as the
equivalent of prison er‘s dilemmas. Put crudely, the dilemma that players
face lies in deciding whether to reciprocate (cooperate – in a sense the
equivalent of reciprocal altruism) or to cheat (defect).
If as Ridley claims, prisoner‘s dilemmas are all around us and if the on ly
logical act is to defect/cheat then how can we explain the regular
reciprocal altruism that we encounter in human societies (and in at least
some social animals)?
Many researchers claim that we should not expect to see cooperation
under such circumstanc es. And yet – all around us people do cooperate.
The mathematicians who initially explored prisoner‘s dilemma in the
1960s also found that people often cooperated on the game even though
this seemed illogical.
They concluded that people just don‘t act rat ionally – that they weren‘t
sophisticated enough to realise that double defection is the only logical
response (Rapoport and Chummah, 1965). But if prisoner‘s dilemma is a
model of the sort of decisions, we face all of the time, then surely, we
should have evolved to play the game rationally? The answer came when
animal behaviourists pointed out that real -life social relations are rarely
like a one -off game of prisoner‘s dilemma but that social animals
encounter each other repeatedly and remember what happe ned on the last
encounter. So social life is more akin to a series of such games where the
same players meet each other frequently.
Whereas in ‗one -shot‘ prisoner‘s dilemma, defection is the only logical
option, when the game is played repeatedly by the sa me two players they
will frequently fall into a pattern of mutual cooperation. In this way, both
continually gain three points.
But why exactly is tit -for-tat so successful against all other strategies?
Political scientist Robert Axelrod, who has frequent ly examined prisoner‘s
dilemma, considers TFT to be an evolutionarily stable strategy (or ESS).
An ESS is a strategy that cannot be bettered provided sufficient members
of a group adopt it (Maynard -Smith, 1974).
Today many social scientists consider that tit-for-tat describes well a
common strategy that people employ when deciding how to respond to
others. In addition to helping to describe and explain general incidents of
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28 warfare – both for the escalation of violence (Chagnon, 1983) and in some
cases its dissipation (Axelrod, 1984).
1.10 SUMMARY Evolutionary biology has undergone many historical developments.
Evolution was suspected to occur long before Charles Darwin proposed
his the ory of natural selection. Missing before him, however, was a theory
about a causal process that could explain how changes in life forms could
occur. The theory of natural selection was Darwin‘s first contribution to
evolutionary biology. Natural selection occurs when some inherited
variations lead to greater reproductive success than other inherited
variations.
In short, natural selection is defined as changes over time due to the
differential reproductive success of inherited variants. Natural selection
theory provides a causal process by which change, the modification of
organic structures, takes place over time. Second, it proposed a theory to
account for the origin of new species. Third, it united all living forms into
one grand tree of descent and simul taneously revealed the place of humans
in the grand scheme of life.
The fact that it has now survived more than a century and a half of
scientific scrutiny, despite many attempts to find flaws in it, must surely
qualify it as a great scientific theory (Ale xander, 1979; Dennett, 1995).
Darwin devised a second evolutionary theory: the theory of sexual
selection. Sexual selection deals with the evolution of characteristics due
to success in mating rather than to success in survival. Sexual selection
operates t hrough two processes: intrasexual competition and intersexual
selection.
A major problem with Darwin‘s theory was that it lacked a workable
theory of inheritance. This theory was provided when the work of Gregor
Mendel was recognized and synthesized with Darwin‘s theory of natural
selection in a movement called the Modern Synthesis. According to this
theory, inheritance does not involve blending of the two parents but rather
is particulate. Genes, the fundamental unit of inheritance, come in discrete
packe ts that are not blended but rather are passed on intact from parent to
child. The particulate theory of inheritance provided the missing
ingredient to Darwin‘s theory of natural selection.
In 1964, the theory of natural selection was reformulated in a
revolutionary pair of articles published by W. D. Hamilton. The process
by which selection operates, according to Hamilton, involves not just
classical fitness (the direct production of offspring), but also inclusive
fitness, which includes the effects of an i ndividual‘s actions on the
reproductive success of genetic relatives, weighted by the appropriate
degree of genetic relatedness. The inclusive fitness reformulation provided
a more precise theory of the process of natural selection by promoting a
―gene‘s e ye‖ view of selection. munotes.in

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29 Foundation of Evolutionary Psychology - I In 1966, George Williams published the now -classic Adaptation and
Natural Selection, which had three effects. First, it led to the downfall of
group selection. Second, it promoted the inclusive fitness revolution and
helped to marsha l in differential gene reproduction that is the central
causal process of evolution by selection. And third, it provided rigorous
criteria for identifying adaptations, such as efficiency, reliability, and
precision.
In the 1970s, Robert Trivers built on th e work of Hamilton and Williams,
offering three seminal theories that remain important today: reciprocal
altruism, parental investment, and parent –offspring conflict.
In 1975, Edward O. Wilson published Sociobiology: A New Synthesis,
which attempted to syn thesize the key developments in evolutionary
biology. Wilson‘s book created controversy, mostly because of its final
chapter, which focused on humans, offering a series of hypotheses but
little empirical data.
As far as levels of evolutionary hypotheses ar e concerned, there are three
evolutionary levels: general level theories, middle -level evolutionary
theories and specific evolutionary hypotheses about empirical phenomena
derived from these hypotheses.
One method of hypothesis generation is to start at t he higher levels and
move down. A middle -level theory can produce several hypotheses, each
of which in turn yields several testable predictions. This can be described
as the ―top -down‖ strategy of hypothesis and prediction formation.
A second method is to start with a phenomenon known or observed to
exist. From this phenomenon, one can generate hypotheses about the
possible function for which it was designed. This is called as bottom -up
method.
The evolutionary process produces three products: adaptations, by-
products of adaptations, and random effects or noise.
Evolutionary game theory (EGT) is the application of game theory to
evolving populations in biology. It defines a framework of contests,
strategies, and analytics into which Darwinian competition can be
modelled. It originated in 1973 with John Maynard Smith and George R.
Price's formalisation of contests, analysed as strategies, and the
mathematical criteria that can be used to predict the results of competing
strategies.
Evolutionary game theory has helped to explain the basis of altruistic
behaviours in Darwinian evolution. It has in turn become of interest to
economists, sociologists, anthropologists, and philosophers.
1.11 QUESTIONS Q. 1 Discuss landmarks in the history of evolutionary thinking.
Q. 2 Describe Darwin‘s theory of natural and sexual selection. munotes.in

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30 Q. 3 Write in detail on evolutionary game theory
Q. 4 Write Short Notes
a) The Ethology Movement
b) Trivers‘s Seminal Theories
c) Specific Evolutionary Hypotheses
1.12 REFERENCES  Buss, D. (2011). Ev olutionary Psychology: A new Science of Mind.
Pearson Education.
 https://en.wikipedia.org/wiki/ Evolutionary_game_theory#:~:text=Evo
lutionary%20game%20theory%20(EGT)%20is,Maynard%20Smith%
20and%20George%20R .

*****

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31 2
FOUNDATION OF EVOLUTIONARY
PSYCHOLOGY – II
Unit Structure
2.0 Objectives
2.1 Introduction
2.2 Definition of an Evolved Psychological Mechanism
2.3 Properties of Evolved Psychological Mechanisms
2.4 Learning, Culture, and Evolved Psychological Mechanisms
2.5 Methods for Testing Evolutionary Hypotheses
2.6 Sources of Data for Testing Evolutionary Hypotheses
2.7 Use and Misuse of Darwinism
2.8 Summary
2.0 OBJECTIVES  After learning this chapter, you will understand various evolved
psychological mechanisms and their properties.
 You will gather knowl edge regarding the influence of culture on
evolved psychological mechanisms.
 You will also learn about methods of testing evolutionary hypotheses
and various sources from which data can be gathered in order to test
the evolutionary hypotheses.
In this sect ion, the core of human nature from an evolutionary
psychological perspective will be addressed. First, all species, including
humans, have a nature that can be described and explained. Second, a
definition of evolved psychological mechanisms — the core unit s that
comprise human nature, will be provided. Finally, important properties of
evolved psychological mechanisms will be examined.
2.1 INTRODUCTION All Species Have a Nature :
It is part of the male lion’s nature to walk on four legs, grow a large furry
mane, and hunt other animals for food. It is part of the butterfly’s nature to
enter a flightless pupa state, wrap itself in a cocoon, and emerge to soar,
fluttering gracefully in search of food and mates. It is part of the
porcupine’s nature to defend itsel f with quills, the skunk’s to defend itself
with a spray, the stag’s to defend itself with antlers, and the turtle’s to
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32 for each species. Each species has faced somewhat unique selection
pressures during its evolutionary history and therefore has confronted a
somewhat unique set of adaptive problems.
In the same way, humans also have a nature —qualities that define us as a
unique species —and all psychological theories imply its e xistence. For
Sigmund Freud, human nature consisted of sexual and aggressive impulses
whereas, for William James, human nature was all about instincts. Even
the most ardent environmentalist theories, such as B. F. Skinner’s theory
of behaviorism, maintaine d that humans have a nature —in this case,
consisting of a few general learning mechanisms. All psychological
theories require at their core fundamental premises about human nature.
Because evolution by selection is the only known causal process capable
of producing the fundamental components of that human nature, all
psychological theories are evolutionary. If humans have a nature and
evolution by selection is the causal process that produced that nature, then
the obvious next question is: What insights int o human nature can be
obtained by examining our evolutionary origins? Can examining the
process of evolution tells us anything about the products of that process in
the human case? Answers to these key questions form the core of the rest
of this book. Wher eas the broader field of evolutionary biology is
concerned with the evolutionary analysis of all the parts of an organism,
evolutionary psychology focuses more narrowly on those parts that are
psychological —the analysis of the human mind as a collection of evolved
information -processing mechanisms and the behaviors generated by those
mechanisms. And so, we turn now to the class of adaptations that make up
the human mind: evolved psychological mechanisms.
2.2 DEFINITION OF AN EVOLVED PSYCHOLOGICAL MECHANISM An evolved psychological mechanism is a set of processes inside an
organism with the following properties:
1. An evolved psychological mechanism exists because it solved a
specific problem :
An evolved psychological mechanism solved a specific problem of
survival or reproduction over evolutionary history that is why it exits in
the present form. This means that the design features of a psychological
mechanism must be coordinated with the features required to solve an
adaptive problem of survival or reproduct ion.
2. An evolved psychological mechanism is designed to take in only a
narrow slice of information :
Only a narrow slice of information from the environment is taken by
evolved psychological mechanisms. Consider the human eye. It looks as
though we open our eyes and see nearly everything, the eye is actually
sensitive only to a narrow range of input from the broad spectrum of
electromagnetic waves —those within the visual spectrum. For example, munotes.in

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33 Foundation Of Evolutionary Psychology – II we cannot see X -rays. We cannot even see radio waves. The eye is not an
all-purpose seeing device. It is made in a way to process only narrow
information —from among the much larger domain of potential
information.
In the same way, the psychological mechanism of a predisposition to learn
to fear snakes is meant to t ake in only very little information —slithery
movements from self -propelled elongated objects. Our evolved
preferences for food, landscapes, and mates are all designed to take in only
a limited subset of information from among the infinite array that could
potentially constitute input.
3. Input of an evolved psychological mechanism tells an organism the
particular adaptive problem it is facing :
The input of seeing a moving snake tells you that you are facing a
particular survival problem, namely, physical damage and perhaps death if
bitten. The different smells of edible objects —rotting versus sweet and
fragrant —tell you that you are facing an adaptive survival problem of food
selection. It can be said that the input lets the organism know which
adaptive pr oblem it is dealing with. This occurs outside consciousness. For
example, we do not smell a cake baking and think, “Oh! I am facing an
adaptive problem of food selection!” Instead, the smell unconsciously
triggers food selection mechanisms and no awareness of the adaptive
problem is necessary.
4. The input of an evolved psychological mechanism is transformed
through decision rules into output :
Let us continue with our earlier example of snake. After seeing a snake,
you have three options: you can decide to attack it, run away from it, or
freeze. Upon smelling a cake just out of the oven, you can choose to eat it
or walk away from it. The decision rules are sets of procedures — “if,
then” statements —for guiding an organism down one path or another. For
exampl e, while publicly arguing with an angry person, humans might have
“if, then” decision rules such as: “If the angry rival is larger and stronger,
then avoid a physical fight; if the angry person is smaller and weaker, then
accept the public challenge and fi ght.” In this example, inputs (a
confrontation by an angry person of a particular size) are transformed
through decision rules (“if, then” procedures) into output (behavior to
either fight or flee) (Figure 2.1).
Evolved Psychological Mechanisms :



Figu re 2.1: A modern formulation of evolved psychological
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Evolutionary Psychology
34 Source: Evolutionary Psychology: The New Science of the Mind by
David Buss, 5th Ed.
5. The output of an evolved psychological mechanism can be a
physiolo gical activity, information to other psychological mechanisms,
or manifest behavior :
You may get physiologically aroused or frightened (physiological output)
on seeing a snake; you may use this information to evaluate your
behavioral options such as freezi ng or fleeing (information to other
psychological mechanisms); or you can use this evaluation for action, such
as running away (behavioral output).
Consider another example: sexual jealousy. Let’s say you go to a party
with your wife and then leave the roo m to get a drink. When you return,
you find your wife is smiling and talking with another person. You also
notice they are holding each other’s hands. These cues might trigger the
feeling of jealousy in you. The cues act as input to the mechanism,
signalli ng to you an adaptive problem —the threat of losing your
partner/wife. This input is then evaluated according to a set of decision
rules. One option is to ignore the two of them and feign indifference.
Another option is to threaten the rival. A third option is to become enraged
and hit the rival. Still another option would be to re -evaluate your
relationship. Thus, the output of a psychological mechanism can be
physiological (arousal), behavioral (confronting, threatening, hitting), or
input into other psych ological mechanisms (re -evaluating the status of
your relationship).
6. The output of an evolved psychological mechanism is directed
toward the solution to a specific adaptive problem :
In our previous example, just as the cues to a partner/wife’s potential
infidelity signal the presence of an adaptive problem, the output of the
sexual jealousy mechanism is meant toward solving that problem. Here
you have a few options: you may leave the scene, your partner/wife may
be persuaded to keep away from flirting wi th others, or you may re -
evaluate your relationship with your wife. These options might help with
the solution to your adaptive problem. Saying that the output of a
psychological mechanism leads to solutions to specific adaptive problems
does not mean that the solutions will always be successful. The output of a
psychological mechanism always does not lead to a successful solution,
but rather that the output of the mechanism on average tends to solve the
adaptive problem better than competing strategies in the environments in
which it evolved.
It can be said that a mechanism that led to a successful solution in the
evolutionary past may or may not lead to a successful solution now. For
example, our taste preferences for fat and sugar were adaptive in our
evolutionary past because fat from meat and sugar from ripe fruits were
valuable and provided sources of calories. Today, we have sugar -laden
soft drinks available on every street corner, fat and sugar are no longer
scarce resources. Thus, our strong taste fo r such substances now cause us munotes.in

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35 Foundation Of Evolutionary Psychology – II to overconsume fat and sugar, which can lead to clogged arteries and heart
attacks and thereby hinder our survival. The point is that evolved
mechanisms exist in the forms that they do because they led to success on
average d uring the period in which they evolved. Whether they are
currently adaptive - that is whether they currently lead to increased survival
and reproduction —is an empirical matter that must be determined on a
case-by-case basis.
In summary, an evolved psycholog ical mechanism is a set of procedures
within the organism designed to take in a particular slice of information
and transform that information via decision rules into output that
historically has helped with the solution to an adaptive problem.
Psychologic al mechanisms exist in current organisms because they led, on
average, to successful solutions to specific adaptive problems for that
organism’s ancestors.
2.3 PROPERTIES OF EVOLVED PSYCHOLOGICAL MECHANISMS This section will examine several important prope rties of evolved
psychological mechanisms.
They provide non -arbitrary criteria for “carving the mind at its natural
joints” and tend to be problem -specific, numerous, and complex. These
features combine to yield the tremendous flexibility of behavior that
characterizes modern humans.
Evolved Psychological Mechanisms Provide Non -arbitrary criteria for
“Carving the Mind at Its Joints” :
Evolutionary psychology maintains that there is primary non -arbitrary way
to identify, describe, and understand psychological mechanisms. This way
is to articulate their functions — the specific adaptive problems they were
designed by selection to solve.
Let us consider the human body. In principle, the mechanisms of the body
could be described in a number of ways. Why do researc hers identify as
separate mechanisms the liver, the heart, the hand, the nose, and the eyes?
The answer is simple. It is based on function. The liver is recognized as a
mechanism that performs functions different from those performed by the
heart or the ha nd. The eyes and the nose, although located close together,
perform different functions and operate according to different inputs
(electromagnetic waves in the visual spectrum versus odors). If an
anatomist tried to lump the eyes and the nose into one cate gory, it would
seem ludicrous. Understanding the component parts of the body requires
the identification of function. Function provides a non -arbitrary way to
understand these component parts.
Evolutionary psychologists believe that the same principles sho uld be used
for understanding the mechanisms of the mind. Although the mind could
be divided in many ways, most of them would be arbitrary. A powerful
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Evolutionary Psychology
36 two components of the mind per form different functions, they can be
regarded as separate mechanisms.
Evolved Psychological Mechanisms Tend to Be Problem Specific
Imagine giving someone directions to get from Kolkata to a specific street
address in Mumbai, Maharashtra. If you gave gener al directions such as
“head west,” the person might end up as far south as Bangalore or as far
north as Delhi. The general direction would not reliably get the person to
the right state.
Now let’s suppose that the person did get to the right state. The “he ad
west” direction would be virtually useless because the west of
Maharashtra is an ocean. The general direction would not provide any
guidance to get to the right city within Maharashtra, let alone the right
street address. To get the person to the right state, city, street, and location
on that street, you would need to give more specific instructions.
Furthermore, although there are many ways to get to a particular street
address, some paths will be far more efficient and time -saving than others.
The sea rch for a specific street address on the other side of the country is a
good analogy for what is needed to reach a specific adaptive solution.
Adaptive problems, like street addresses, are specific —don’t get bitten by
that snake, select a habitat with runn ing water and places to hide, avoid
eating food that contains toxins or parasites, select a mate who is fertile,
and so on. There is no such thing as a general adaptive problem (Symons,
1992).
Because adaptive problems are specific, their solutions tend to be specific
as well. Just as general instructions fail to get you to the correct location,
general solutions fail to get you to the right adaptive solution.
Consider two adaptive problems: selecting the right foods to eat (a
survival problem) and selectin g the right mate with whom to have children
(a reproduction problem). What counts as a “successful solution” differs
greatly for the two problems. Successful food selection involves
identifying objects that have calories, have particular vitamins and
miner als, and do not contain poisonous substances.
Successful mate selection typically involves, among other things,
identifying a partner who is fertile and will be a good parent.
What might be a general solution to these two selection problems, and
how effect ive would it be at solving them? One general solution would be
“select the first thing that comes along.” This would be disastrous because
it might lead to eating poisonous plants or marrying an infertile person. If
anyone had implemented such a general so lution to these adaptive
problems in human evolutionary history, he or she would have failed to
become one of our ancestors.
To solve these selection problems, one needs more specific guidance
about the important qualities of foods and mates. Fruit that lo oks fresh and munotes.in

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37 Foundation Of Evolutionary Psychology – II ripe, for example, will signal better nutrients than fruit that looks rotten.
People who look young and healthy will be more fertile, on average, than
people who look old and ill.
In summary, problem specificity of adaptive mechanisms tends to be
favored over generality because (1) general solutions fail to guide the
organism to the correct adaptive solutions; (2) even if they do work,
general solutions lead to too many errors and thus are costly to the
organism; and (3) what constitutes a “s uccessful solution” differs from
problem to problem.
Humans Possess Many Evolved Psychological Mechanisms :
Humans, like most organisms, face a large number of adaptive problems.
The problems of survival alone number in hundreds —problems of thermal
regulati on (being too cold or too hot), avoiding predators and parasites,
ingesting life -sustaining foods, avoiding falls from great heights, staying
away from dangerous strangers, and so on. Then there are problems of
mating such as selecting, attracting, and kee ping a good mate and getting
rid of a bad mate. There are also problems of parenting such as
breastfeeding, weaning, socializing, and attending to the varying needs of
different children.
Then there are the problems of investing in kin, such as brothers, s isters,
nephews, and nieces; dealing with social conflicts; defending against
aggressive groups; and grappling with the social hierarchy. Because
specific problems require specific solutions, numerous specific problems
will require numerous specific soluti ons. Just as our bodies contain
thousands of specific mechanisms —a heart to pump blood, lungs for
oxygen uptake, a liver to filter out toxins — the mind, according to this
analysis, must also contain hundreds or thousands of specific mechanisms.
Because a l arge number of different adaptive problems cannot be solved
with just a few mechanisms, the human mind must be made up of a large
number of evolved psychological mechanisms.
The Specificity, Complexity, and Numerousness of Evolved
Psychological Mechanisms Give Humans Behavioral Flexibility
The definition of a psychological mechanism, including the key
components of input, decision rules, and output, highlights why
adaptations are not rigid “instincts” that invariably manifest in behavior.
Let us consider th e callus -producing example again. The callus -producing
mechanisms that have evolved to protect the structures beneath the skin.
You can design your environment so that you don’t experience repeated
friction. In this case, your callus -producing mechanisms w ill not be
activated. The activation of the mechanisms depends on input from the
environment. In the same way, all psychological mechanisms require input
for their activation.
Psychological mechanisms are not like instincts for another important
reason — the decision rules. Decision rules are “if, then” procedures such
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Evolutionary Psychology
38 I’m attracted to shows interest, then smile.” For most mechanisms, these
decision rules permit at least several poss ible response options. Even in
the simple case of encountering a deadly snake, you have the option of
attacking it with a stick, freezing and hoping it will go away, or fleeing for
your life.
Humans gain flexibility from having a large number of complex, s pecific,
functional psychological mechanisms. With each new mechanism that is
added to the mind, an organism can perform a new task.
Beyond Domain -Specific Psychological Mechanisms :
All of the evidences point out that humans must possess a large number of
specialized psychological mechanisms, each dedicated to solving specific
adaptive problems. This conclusion is widely accepted within the field of
evolutionary psychology and lies at the foundation of evolutionary
approaches to all species (Alcock, 2013).
The idea that a single generic substance can see in depth, control the
hands, attract a mate, bring up children, elude predators, outsmart prey,
and so on, without some degree of specialization, is not credible.
Some evolutionary psychologists argue tha t in addition to specific
mechanisms, humans also have evolved several domain -general
mechanisms (e.g., Chiappe & MacDonald, 2005; Figueredo, Hammond, &
McKiernan, 2006; Geary & Huffman, 2002; Livingstone, 1998; Mithen,
1996; Premack, 2010). Examples of pr oposed general mechanisms are
general intelligence, concept formation, analogical reasoning, working
memory, and classical conditioning.
The proponents of domain -general mechanisms maintain that although
recurrent features of adaptive problems select for s pecialized adaptations,
humans have faced many novel problems that did not recur with sufficient
regularity for specific adaptations to have evolved. Furthermore, we know
that humans routinely solve ancient adaptive problems in highly novel
ways; for examp le, we can get food from a vending machine, mates from
the Internet, and tools from a hardware store. Everyone recognizes that
humans have been able to flourish in an environment very different from
that in which we evolved, “a constantly changing world fa r removed from
the Pleistocene” (Chiappe & MacDonald, 2005). According to Chiappe
and MacDonald (2000) domain -general mechanisms, such as general
intelligence, evolved to “allow for the solution of non -recurrent problems
in attaining evolutionary goals” (2 005) or to develop new solutions to old
problems.
There is a debate whether psychological mechanisms are domain -general
or domain -specific. It can be summarized that evolved psychological
mechanisms clearly interact with each other in complex ways. They ar e
turned on and off in various sequences that are not fully understood. The
possibility that humans possess evolved superordinate regulatory
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39 Foundation Of Evolutionary Psychology – II 2.4 LEARNING, CULTURE, AND EVOLVED PSYCHOLOGICAL MECHANISM S A common question that arises: Aren’t the human behaviors we observe
caused by learning and culture, not evolution? Aren’t human behaviors the
product of nurture, not nature? To answer these questions, we must
analyze the precise form of explanations tha t invoke psychological
adaptations and the form of those that invoke learning and culture.
To start with, the framework of evolutionary psychology dissolves
dichotomies such as “nature versus nurture,” “innate versus learned,” and
“biological versus cultur al.” If you go back to the definition of evolved
psychological mechanisms, you will note that (1) environments featuring
recurrent selection pressure over deep time formed each mechanism; (2)
environmental input during a person’s development is necessary f or the
emergence of each mechanism; and (3) environmental input is necessary
for the activation of each mechanism. Thus, it does not make sense to ask
whether a callus or jealous behavior is “evolved” or “learned.” “Evolved”
is not the opposite of “learned .” All behavior requires evolved
psychological mechanisms combined with environmental input at each
stage in the causal chain.
We can ask the question precisely what it means to say that something is
learned. Humans do learn, of course. They are affected b y their
environments and cultures. Learning, however, requires structures in the
brain —evolved psychological mechanisms —that enable them to learn.
The explanatory challenge is not well met simply by slapping the label
“learning” on a behaviour. We have to identify the nature of the
underlying learning mechanisms that enable humans to change their
behaviour as a consequence of environmental input. Now, what is the
nature of these learning mechanisms? Let’s consider three concrete
examples: (1) people learn t o avoid having sex with their close genetic
relatives (learned incest avoidance); (2) people learn to avoid eating foods
that may contain toxins (learned food aversions); (3) people learn from
their local culture which actions increase social status and pr estige
(learned prestige criteria). There is compelling evidence that each of these
forms of learning are best explained by different evolved learning
mechanisms.
Solving the adaptive problem of incest avoidance requires learning about a
class of individua ls—one’s close genetic relatives —with whom one
should not have sex. How can people learn who these individuals are? The
evolved incest avoidance learning mechanism functions by using a reliable
kinship cue —those with whom you grow up. Duration of co-reside nce
with a member of the opposite sex during childhood powerfully predicts a
lack of sexual attraction —and the amount of repulsion people experience
at the thought of having sex with them (Lieberman, Tooby, & Cosmides,
2003).
Now let us consider learned fo od aversions. We learn food aversions
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40 certain foods. Those who have an intense dislike of mushrooms or liver or
fish typically have experienced an earlier event in which they got sick
after c onsuming such food.
Finally, consider how we learn which cues in our local culture are linked
with status and prestige. Among hunter -gatherer societies, good hunting
skills lead to prestige. In academia, individuals who have prominent
publications that are cited a lot by other scholars attain high prestige.
Among other local cultures, the number of tattoos, size of motorcycle, or
skill at guitar playing or video game playing is associated with high
prestige. People learn prestige criteria, in part, by focus ing on the attention
structure —those high in prestige are typically those to whom the most
people pay the most attention (Chance, 1967). By attending to (and often
trying to imitate) the qualities, clothing styles, and behaviours of those to
whom others pa y the most attention, we learn the prestige criteria of our
local culture (Atkisson & O’Brien, 2012).
These three forms of learning —incest avoidance, food aversion, and
prestige criteria — clearly require different evolved learning mechanisms
to function. E ach form operates on the basis of inputs from a different set
of cues —co-residence during development, nausea paired with food
ingestion, and the attention structure, respectively. Each has different
functional output —lack of sexual attraction to genetic r elatives, disgust at
the sight and smell of certain substances, and attention to those to whom
others are attending. And importantly, each form of learning solves a
different adaptive problem.
There are three critical points to draw from this analysis. Fir st, labelling
something as “learned” does not provide an explanation; it is simply a
description that environmental input changes the organism in some way.
Second, “learned” and “evolved” are not competing explanations; rather,
learning requires psychologi cal adaptations. Third, evolved learning
mechanisms are often specific in nature.
2.5 METHODS FOR TESTING EVOLUTIONARY HYPOTHESES Once hypotheses are formulated, the next step is to test them empirically.
Evolutionary psychologists have proposed many metho ds to test the
hypotheses (Schmitt, 2008; Simpson & Campbell, 2005). (Table 2.1). Methods for Testing Evolutionary Hypotheses Sources of Data for Testing Evolutionary Hypotheses 1. Compare different species 1. Archaeological records 2. Cross-cultural methods 2. Data from hunter-gatherer societies 3. Physiological and brain imaging methods 3. Observations munotes.in

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41 Foundation Of Evolutionary Psychology – II 4. Genetic methods 4. Self -reports 5. Compare male and female records 5. Life-history data and public 6. Compare individuals within a species 6. Human products 7. Compare the same individuals in different contexts 8. Experimental methods
Table 2.1 Methods and Data Sources for Testing Evolutionary
Hypotheses
Source: Evolutionary Psychology: The New Science of the Mind by David
Buss, 5th Ed.
Comparing Different Species :
Comp aring species that differ along particular dimensions provides one
source of evidence for testing functional hypotheses. The comparative
method involves “testing predictions about the occurrence of the trait
among species other than the animals whose behav ior the researcher is
trying to understand” (Alcock, 1993). For example, let us consider the
following sperm competition hypothesis : The function of producing
large sperm volume is to displace competing males’ sperm and hence
increase the odds of fertilizi ng a female’s egg.
One strategy for testing this hypothesis is to compare species that differ in
the prevalence of sperm competition. In highly monogamous species,
sperm competition is rare or absent. In certain species of birds (e.g., ring
doves) and mamm als (e.g., gibbons), males and females pair off to
produce offspring and rarely have sex outside the pair -bond.
In other species, such as bonobo chimpanzees, females will copulate with
a number of males (de Waal, 2006). In this species, there is a great de al of
sperm competition. Thus, we know that sperm competition is high in
promiscuous species and low in monogamous species.
Now let us test this hypothesis. We can line up species by the degree to
which sperm competition is likely to be prevalent. Among pr imates, for
example, gorillas are least promiscuous, followed by orangutans, humans,
and chimpanzees, which are the most promiscuous. Next, we can obtain
comparative data on the sperm volume in each of these species as
indicated by testicular weight, corre cted for body size. The prediction
from the sperm competition hypothesis is that males in species that show a
lot of sperm competition should have higher testicular weight (indicating a
high volume of sperm) compared with species that show lower levels of
sperm competition.
The comparative evidence reveals that the testes of male gorillas account
for 0.02 percent of body weight; of male orangutans, 0.05 percent of body
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42 promiscuous chimpa nzees, 0.27 percent of body weight (Short, 1979;
Smith, 1984). In sum, males in the species showing intense sperm
competition display larger testicular volume; males in the species with the
least sperm competition display the lowest testicular volume
Cross -Cultural Methods :
Cross -cultural methods provide valuable tools for testing evolutionary
psychological hypotheses (Schmitt, 2008). The most obvious method
pertains to adaptations that are hypothesized to be universal, such as basic
emotions (Ekman, 1973), adaptations for cooperation (Cosmides &
Tooby, 2005), or sex -differentiated mating strategies (Lippa, 2009;
Schmitt, 2005). Comparing different cultures can also be used to examine
Adaptations hypothesized to respond to differing ecologies. Mate
preferenc es, for example, have been hypothesized to be sensitive to
ecological variations in parasite prevalence, which has been confirmed in
a study of thirty -seven cultures (Gangestad, Haselton, & Buss, 2006).
Cross -cultural methods can also be used to test compe ting theories by
pitting them against each other. Lippa, Collaer, and Peters (2010)
explored gender differences in a mental rotation task across fifty -
three cultures. Mental rotation ability has been hypothesized to be part of
a male hunting adaptation bec ause hunters have to anticipate the
trajectories of spears and other hunting implements as they move through
space to coincide with the trajectory of a moving animal. In contrast,
according to social role theory, psychological gender differences are
hypoth esized to be a function of the roles assigned by different cultures,
and hence should diminish as equality between the sexes increases.
Lippa’s cross -cultural study found two key findings: (1) the gender
differences in mental rotation ability were universa l across cultures, and
(2) contrary to social role theory, the gender differences were actually
somewhat larger in cultures with more gender equality. Cross -cultural
methods, in short, are extremely valuable for testing a range of
evolutionary hypotheses, as well as for pitting competing hypotheses
against each other.
Physiological and Brain Imaging Methods :
Physiological methods can be used to assess phenomena such as emotional
arousal, sexual arousal, and stress. These methods can be used both to
identify the biological substrates of psychological adaptations as well as to
test hypotheses about design features of those adaptations. Flinn, Ward,
and Noone (2005) tested the hypothesis that children living with
stepparents would experience higher levels of st ress than children
living with two biological parents. They found that stepchildren had
higher levels of cortisol —one of the key hormones that gets released when
people experience stress —than non -stepchildren. Another study confirmed
the hypothesis that te stosterone, one of the key hormones involved in mate
competition, would be reduced in men who were in committed romantic
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43 Foundation Of Evolutionary Psychology – II become valuable both in testing hypotheses about adaptations as we ll as in
identifying the underlying substrates of adaptations.
Brain imaging techniques, such as functional magnetic resonance imaging
(fMRI), are increasingly being used to test hypotheses about adaptations
and their underlying neural basis. FMRI methods have been used to test
hypotheses about adaptations for kin recognition, language, spatial
cognition, romantic attraction, and jealousy (Platek, Keenan, &
Shackelford, 2007).
Genetic Methods :
Genetic methods, such as twin studies and adoption studies, can be used to
test some evolutionary hypotheses (Segal, 2011). One evolutionary
hypothesis proposes a context -dependent adaptation in females to
shift to early onset of sexuality and age of first menstruation when
growing up without an investing father aroun d, compared to a delayed
onset of sexuality when there is an investing father (e.g., Belsky, 1997;
Ellis, 2011). Behavioral genetic methods can determine whether individual
differences in onset of female sexuality is environmentally mediated, as
the evolut ionary hypothesis suggests, or instead is genetically mediated,
which would refute the hypothesis.
Comparing Males and Females :
Sexually reproducing species usually come in two forms: male and
female. Comparing the sexes provide another method for testing
hypotheses about adaptation. One strategy involves analyzing the different
adaptive problems faced by males and females. In species with internal
female fertilization, for example, males face the adaptive problem of
“paternity uncertainty.” They never can “know” with complete certainty
whether they are the genetic father of their mate’s offspring. The females,
however, do not confront this adaptive problem. They “know” that their
own eggs, not a rival’s eggs, are fertilized because the eggs can only come
from within themselves.
Males have evolved specific adaptations that function to increase their
chances of paternity. One example will explain the point here: male sexual
jealousy. Although both sexes are equally jealous overall, studies have
shown that men ’s jealousy, far more than women’s, is activated
specifically by signals of sexual infidelity, suggesting one solution to the
problem of paternity uncertainty (Buss, Larsen, Westen, & Semmelroth,
1992; Schützwohl, 2008). Men’s jealousy motivates behavior t o repel a
rival or to dissuade a mate from infidelity.
The fact that men’s jealousy is especially triggered by cues to sexual
infidelity points to a facet of men’s psychology that corresponds to a sex -
linked adaptive problem —that of uncertainty of parentho od. In sum,
comparing the sexes within one species can be a powerful method of
testing evolutionary hypotheses.
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44 Comparing Individuals within a Species :
Another method involves comparing some individuals with other
individuals within one species. Consider young and older women.
Teenage girls have many years of potential reproduction ahead of them;
women in their late thirties have fewer fertile years left.
We can use these differences to formulate and test hypotheses about
adaptation. For example, suppose y ou hypothesized that younger women
would be more likely to abort a developing fetus than older women if
there weren’t an investing man around to help. The evolutionary rationale
is this: Because they have many reproductive years left, younger women
can “af ford” to lose the chance to have a child to wait for a more
opportune time to reproduce. The older woman may not get another
chance to have a child. Comparing the rates of abortion, miscarriage, and
infanticide in the two groups of women provides one metho d for testing
this hypothesis.
Comparing individuals within a species is not restricted only to age. We
can compare individuals who are poor to those who are rich to test the
hypothesis that the poor will engage in “riskier” strategies of acquiring
resourc es; the rich might be more “conservative” to protect their wealth.
We can compare individuals who differ in their desirability as mates or
individuals who differ in the sizes of their extended families. In short,
within -species comparison constitutes a pow erful method for testing
evolutionary hypotheses about adaptation.
Comparing the Same Individuals in Different Contexts :
Another approach is to compare the same individuals in different
situations. For example, among the Siriono of eastern Bolivia, one man
who was an unsuccessful hunter had lost several wives to men who were
better hunters. He suffered a loss of status within the group, due to both
his poor hunting and his loss of wives to other men.
Anthropologist A. R. Holmberg (1950) took up hunting with this man,
gave him game that others were later told the man had killed, and taught
him the art of killing game with a shotgun. Eventually, as a result of the
man’s increased hunting success, he enjoyed an increase in social status,
attracted several women as sex partners, and started insulting others rather
than being the victim of insults.
Comparing the same individuals in different situations is a powerful
method for understanding evolved psychological mechanisms.
Hypotheses can be formulated about the a daptive problems
confronted in two different situations and hence about which
psychological adaptations will be activated in each. In the case of the
Siriono man who went from low to high -status thanks to a change in his
hunting ability, the higher status apparently caused him to be more self -
confident. It also seems to have affected the psychological mechanisms of
other Siriono men, who shifted from insulting the man to being more
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45 Foundation Of Evolutionary Psychology – II Experimental Methods :
In experiments, one group of subjects is t ypically exposed to a
“manipulation” and a second group serves as a “control.” Let’s say that we
develop a hypothesis about the effect of threat on the tightness of “in -
group cohesion.” The hypothesis states that humans have evolved a
psychological adaptat ion whose function is to react to threats from the
outside , such as an invasion by a hostile group of humans. Under threat
conditions, group cohesion should increase, as manifested by such
tendencies as showing favoritism toward in -group members and showin g
an increase in prejudice toward outgroup members.
In the laboratory, experimenters choose one group of subjects at random
and tell them they may have to go to a smaller room because another
group has first priority on the room they are in. Before they le ave, the
experimenter gives them $100 as payment for participating in the study,
with instructions to divide the money between the two groups however
they want. The control group is also charged with dividing the money
between their group and another group but is not told that the other group
is taking over their room. We can then compare how the control group and
the experimental group decide to split up the money. If there is no
difference between the experimental and control groups, we would
conclude tha t our prediction had failed. If the threatened group allocated
more money to itself but the control group allocated equally, then our
prediction would be confirmed —external threat increases in -group
favouritism. In sum, the experimental method —subjecting d ifferent
groups to different conditions —can be used to test hypotheses about
adaptations.
2.6 SOURCES OF DATA FOR TESTING EVOLUTIONARY HYPOTHESES In addition to the research methods, evolutionary psychologists have a
wealth of other sources from which they can obtain data for testing
hypotheses. This section briefly presents some of these sources.
Archaeological Records :
Bone fragments secured from around the world reveal a paleontological
record filled with interesting artefacts. Through carbon -dating meth ods,
we can obtain rough estimates of the ages of skulls and skeletons and trace
the evolution of brain size through the millennia. Bones from large game
animals found at ancestral campsites can reveal how our ancestors solved
the adaptive problem of secur ing food. Fossilized feces can provide
information about other features of the ancestral diet. Analyses of bone
fragments can also reveal sources of injury, disease, and death. The
archaeological record provides one set of clues about how we lived and
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46 Data from Hunter -Gatherer Societies :
Current studies of traditional peoples, especially those relatively isolated
from Western civilization, also provide a rich source of data for test ing
evolutionary hypotheses. Studies by anthropologists Kim Hill and Hillard
Kaplan (1988) show that successful hunters do not benefit directly from
their efforts because meat is shared by the group, but they do benefit in
other reproductively relevant way s. The children of successful hunters
receive more care and attention from the group, resulting in their superior
health. Successful hunters also are sexually attractive to women and tend
to have more mistresses and more desirable wives. This data source
provides evidence that, in conjunction with other sources of data, allows
us to formulate and test hypotheses about psychological adaptations.
Observations :
Systematic observations provide a third method for testing evolutionary
hypotheses. Anthropologist M ark Flinn devised a behavioral scanning
technique for systematically gathering observations in Trinidad (Flinn,
1988; Flinn, Ward, & Noone, 2005). Every day, he walked through the
argeted village, visiting every household and recording each observation
he made on a record sheet. He was able to confirm, for example, the
hypothesis that men with fertile wives engaged in more intense “mate
guarding” than men with less fertile wives (i.e., those who were pregnant
or old). He determined this through behavioural scans that showed that
men tended to get into more fights with other men when their wives were
fertile and fewer fights when their wives were not fertile. Observational
data can be collected from a variety of sources —trained observers such as
Flinn, husba nds or wives of the target subjects, friends and relatives, even
casual acquaintances.
Self-Reports :
Reports by the actual subjects provide an invaluable source of data. Self -
report data can be secured through interviews or questionnaires. There are
some p sychological phenomena that can be examined only through self -
report. Consider sexual fantasies. These are private experiences that leave
no fossils and cannot be observed by outsiders. In one study, evolutionary
psychologists Bruce Ellis and Donald Symons (1990) tested hypotheses
about sex differences in sexual fantasy. They found that men’s sexual
fantasies tended to involve more sexual partners and more partner
switching and were more visually oriented. Women’s sexual fantasies
tended to have more myster y, romance, emotional expressions, and
context. Without self -report, this sort of study could not be conducted.
Life-History Data and Public Records :
People leave traces of their lives on public documents. Marriages and
divorces, births and deaths, crimes and misdemeanors, are all part of the
public record. In one series of studies, the evolutionary biologist Bobbi
Low (1991) was able to unearth data on marriages, divorces, and
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47 Foundation Of Evolutionary Psychology – II ago. The p riests of these parishes kept scrupulously accurate and detailed
records of these public events. By looking at marriage and divorce rates
from 400 years ago, we can see whether the patterns that occur today are
long-standing and recurrent over human histor y or merely products of our
modern times. Low was able to test a number of evolutionary hypotheses
using these public records. She confirmed, for example, that wealthier
men tended to marry younger (and hence more fertile) women compared
with poorer men.
Public records if used in conjunction with other sources of data, can be
very useful for scientists to test evolutionary psychological hypotheses.
Human Products :
The things humans make are products of their evolved minds. Modern
fast-food restaurants, for example, are products of evolved taste
preferences. Hamburgers, French fries, milkshakes, and pizza are filled
with fat, sugar, salt, and protein. They sell well precisely because they
correspond to, and exploit, evolved desires for these substances. Thus ,
food creations reveal evolved taste preferences. Human creations can
serve as an additional data source for testing evolutionary hypotheses.
2.7 USE & MISUSE OF DARWINISM According to Darwin’s theory of evolution, only the plants and animals
best adapted to their environment will survive to reproduce and transfer
their genes to the next generation. Animals and plants that are poorly
adapted to their environment will not survive to reproduce.
Charles Darwin published his notions on natural selection and th e theory
of evolution in his influential 1859 book On the Origin of Species.
Darwin’s theory of evolution by natural selection was a scientific theory
focused on explaining his observations about biological diversity and why
different species of plants and animals look different.
Social Darwinism is a loose set of ideologies that emerged in the late
1800s in which Charles Darwin’s theory of evolution by natural selection
was used to justify certain political, social, or economic views. Social
Darwinists bel ieve in “survival of the fittest” —the idea that certain people
become powerful in society because they are innately better. Social
Darwinism has been used to justify imperialism, racism, eugenics and
social inequality at various times over the past century and a half.
For evolutionary scientists there is no such thing as "Darwinism". Instead,
we have a scientific theory that, in combination with Mendel's work,
provides the modern or neo -Darwinian synthesis, which explains the
development of life on Earth.
This effectively sets the limits of the usefulness of Darwin's theory.
However, in the last 150 years, there have been many attempts to take
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48 developed, hence the influence of social "Darwin ism" on concepts such as
eugenics and a more recent Darwinian nihilism that absolves the
individual of any moral or social responsibility.
There is an inherent danger in extrapolating science beyond the realm for
which it was intended, but ironically this human trait is perhaps best
understood as an evolutionary hangover from the development of our
massively expanded brainpower. We have an innate need to expand and
develop ideas in order to explain our wider existence or justify our
behaviours.
This inheren t danger of using Darwin's theory outside of its biological
context has led to attempts to portray Darwin as the de facto cause of 20th
century genocide. There is a fallacy at the core of this line of thinking –
can scientists really be held responsible f or what is done with their ideas
when they are misunderstood and corrupted by groups such as the Nazis?
It is argued that they cannot: the actions of criminals do not need such
highbrow justification and trying to do so merely lends a pseudo -scientific
veneer the actions of the Third Reich.
A newer and perhaps more insidious attempt to blame "Darwinism" for
human atrocity comes in the form of Dennis Sewell's book The Political
Gene: How Darwin's Ideas Changed Politics.
Sewell cites Darwin's work as the rea son for the development of
something that he broadly categorises as a form of moral detachment from
societal rules and norms: evolution is random and without purpose
therefore one can do whatever one pleases.
He argues that this moral vacuum can lead to d isturbed teenagers
perpetrating horrific crimes such as the Columbine school massacre.
Sewell does not propose that Darwin's theory leads inevitably to such
actions, however he suggests that some of Darwin's other writings were
racist and not in keeping wi th modern views. This is hardly a stunning
revelation: Darwin was a man of his time and of his society. Sewell is
making a common mistake in grafting the faults and flaws of Darwin the
man onto Darwinian evolution.
An interesting parallel can be seen in h ow Islamists subvert the essentially
peaceful message of Islam into a justification for violence and vitriolic
hate. One can no more blame the actions of misguided Islamists on
Muhammad than the Nazis or high school shooters can be blamed on
Darwin.
Humans have a tremendous capacity for selflessness and creativity but we
also have an equally developed ability to cause destruction and misery.
Both extremes are a result of our evolutionary heritage. If we blame
Darwin for the dark side of human nature, logica lly we must also credit
him with all that is good.
Darwin theory of natural selection and evolution was widely and horribly
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49 Foundation Of Evolutionary Psychology – II as the conditions of life remain the same, we have reason to believe that
modification, which many generations have inherited, may continue to be
inherited”. This shows that nature chooses who lives and dies due to what
traits they have inherited. In simple terms, all the problems branching
from Darwin’s theory is all based on Eugenics. A problem followed this
discovery because it gave people excuses to get what they want.
Thousands of citizens being forced to give up having the ability to have
children because they weren't “adequate enough” by the government was
an awful turning of Darwin’s theory. For example, in 1927, the supreme
court and other branches of government forced a woman to have to get
sterilized or to be unable to have children. One justice wrote afterwards
that “Carrie Buck is a feebleminded white w oman… [who was a] probable
potential parent of socially inadequate offspring”. This shows that they
twisted the idea of natural selection to their idea that inadequate people
will produce inadequate children.
In addition, by 1935, all states but 11 had ha d sterilization laws either in
effect, or pending. Also, by that time, it was “[estimated] that 65,000
Americans were sterilized without consent under these laws”. The
government was forcing thousands of adults to give up their free will and
get sterilized so that there wouldn’t be “inadequate” children. As a result,
they used natural selection as an excuse to restrict child birth to the
general population so that the special few could have “adequate” children.
Racism was already a huge problem with many pe ople, so natural
selection just gave them the opportunity to make use out of it, however
bad it was. For example, by 1919, the amount of people immigrating
increased to about 6 million per decade. This caused Laughlin to said that
new immigrants had high l evels of “feeblemindedness, insanity,
criminality, and dependency”.
An addition, by 1919, most of the population was coming from southern,
eastern, and central Europe. Laughlin said in his testimony to abolish
immigration, the immigrants should take a tes t and “[They] should also be
dependent upon the possession of such physical, mental, and moral
qualities as the American people desire to be possessed inherently by its
future citizenry”. Laughlin is using natural selection as an excuse that
immigrants are n't good enough for us and should be restricted. He had the
opinion that people who weren't white typically weren't pure enough for
us. They had used natural selection to get their own personal goals
accomplished, even if it is not morally or socially cor rect.
Many people through time have agreed that in life, only the strongest will
come out on top and if you are not strong or smart enough you will not
“survive” society. As Herbert Spencer had written about, “Radical defects
are as much causes of death in the one case as in the other”. Also, he talks
about how if you have “incompleteness be in strength, agility, perception,
foresight, or self -control is not heeded, [nature will] purify society from
those who are, in some respect or other, essentially fault y”. He, in simple munotes.in

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50 terms, is saying that if you are not good enough, you will not survive in
the current society.
In addition, Francis Galton added a theory that humans inherited what he
called “noble” human traits, like superior intelligence or abilities. On the
same subject, he felt that there was a “superior [strain]or [race]. In so
favouring them their progeny shall outnumber and gradually replace that
of the old one”. He is saying that the white man race is better than the
other races, and that if you are not white, you will never be the strongest.
They used Darwin’s theory incorrectly to show that if your parents weren't
full white, then the traits inherited from your parents would be “weak” and
you would not survive.
Darwin’s theory was misused on th e misguided idea of Eugenics. All the
problems coming from it (Sterilization, Racism, Survival of the Fittest) are
all on the idea of traits and DNA strands. Throughout history, hundreds of
thousands of people have died to Eugenics. The holocaust was due t o
Hitler thinking the Jews were not good enough along with other lasting
events such as Racism. If Darwin’s ideas were not misinterpreted,
thousands upon thousands of lives would have been greatly different.
2.8 SUMMARY This chapter covered five topics: th e definition of an evolved
psychological mechanism, properties of evolved psychological
mechanisms, methods for testing evolutionary hypotheses, sources of data
for testing evolutionary hypotheses, and use and misuse of Darwinism.
The logic of evolutionary hypotheses starts with an examination of the
four levels of analysis, going from most general to most specific —general
evolutionary theory, middle -level evolutionary theories, specific
evolutionary hypotheses, and specific predictions about empirical
phen omena derived from these hypotheses. One method of hypothesis
generation is to start at the higher levels and move down. A middle -level
theory can produce several hypotheses, each of which in turn yields
several testable predictions. This can be described as the “top -down”
strategy of hypothesis and prediction formation.
A second method is to start with a phenomenon known or observed to
exist, such as the importance men attach to a woman’s appearance. From
this phenomenon, one can generate hypotheses about the possible function
for which it was designed. This bottom -up method is called reverse
engineering and is a useful supplement to the top -down method.
The evolutionary process produces three products: adaptations, by -
products of adaptations, and random ef fects or noise. Evolutionary
psychologists tend to focus on adaptations. More specifically, they focus
on one special subclass of adaptations that comprises human nature:
psychological mechanisms.
Psychological mechanisms are information -processing devices that exist
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51 Foundation Of Evolutionary Psychology – II or reproduction recurrently over human evolutionary history. They are
designed to take in only a narrow slice of information, transform that
information through decision rules, and produce output in the form of
physiological activity, information to other psychological mechanisms, or
manifest behavior. The output of an evolved psychological mechanism is
directed toward the solution to a specific adaptive problem. Evolved
psychological mechanisms provide non -arbitrary criteria for “carving the
mind at its joints,” which tend to be problem -specific, are large in number,
and are functional in nature.
Once a hypothesis about an evolved psychological mechanism is
formulated, th e next step in the scientific endeavor is to test it. Testing
evolutionary hypotheses relies on comparisons, finding out whether
groups that are predicted to differ in a particular way actually do. This
method can be used to test hypotheses by comparing di fferent species,
comparing people in different cultures, comparing people’s physiological
reactions and brain images, comparing people with different genes,
comparing males and females within a species, comparing different
individuals of each sex, and comp aring the same individuals in different
contexts.
Evolutionary psychology has a wealth of additional sources to draw on,
including the archeological record, contemporary hunter -gatherer
societies, self -report, observer report, data evoked from subjects in
laboratory experiments, life -history data from public records, and products
made by people.
Every source of data has strengths, but each also has limitations. Each
provides information that typically cannot be obtained in the same form
through other data s ources. And each has flaws and weaknesses not shared
by others. Studies that test evolutionary hypotheses using two or more data
sources are better than studies that rely on a single source.
The final section of this chapter outlined major classes of adapt ive
problems. Four classes of adaptive problems follow from modern
evolutionary theory: problems of survival and growth, problems of
mating, problems of parenting, and problems of genetic relatives.
Additional insights into identifying adaptive problems co me from
knowledge of universal human structures, traditional tribal societies,
paleoarcheology, task analysis, and current psychological mechanisms.
Current mechanisms such as a fear of heights, a taste for fatty foods, and a
preference for savanna -like la ndscapes provide windows for viewing the
nature of past adaptive problems.
In the end, we discussed the use and misuse of Darwinism. Darwin’s
theory was misused on the misguided idea of Eugenics. All the problems
coming from it (Sterilization, Racism, Surv ival of the Fittest) are all on the
idea of traits and DNA strands. Throughout history, hundreds of thousands
of people have died to Eugenics. The holocaust was due to Hitler thinking
the Jews were not good enough along with other lasting events such as munotes.in

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52 Racism. If Darwin’s ideas were not misinterpreted, thousands upon
thousands of lives would have been greatly different.
2.9 QUESTIONS Q 1 Define evolved psychological mechanism.
Q 2 Describe properties of evolved psychological mechanisms.
Q 3 Discuss the methods for testing evolutionary hypotheses.
Q4 Write Short Notes
1. Physiological and Brain Imaging Methods
2. Sources of Data for Testing Evolutionary Hypotheses
3. Use & misuse of Darwinism
2.10 REFERENCES  Buss, D. (2011). Evolutionary Psychology: A new Science of Mind.
Pearson Education.

*****

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53 3
MAJOR ASPECTS OF EVOLUTIONARY
THEORY: SURVIVAL AND MATING - I
Unit Structure
3.0 Objectives
3.1 Problems of survival
3.1.1 Food acquisition
3.1.2 Human fears
3.1.3.Landscape preferences.
3.2 Mate selection
3.3 Sexual strategies
3.4 Summary
3.5 Ques tions
3.6 References

3.0 OBJECTIVES After studying this unit you should be able to:
 know what are the problems of survival
 Understand food acquisition
 Know about human fears and six defenses in depth.
 Study landscape preferences
 Understand mate selectio n
 Study sexual strategies and problems confronted by men and women
3.1 PROBLEMS OF SURVIVAL Surviving i.e. continuing to live even though there are dangers around us,
can be difficult. According to Darwin, dangers to survival are called
“hostile forces of nature.” They include extreme climate, shortages of
food, toxins, diseases, parasites, predators etc. Humans have evolved
adaptions to fight these barriers to survival. But there are some evolved
mechanisms that help us to survive. In this unit, we are goi ng to talk about
some problems of survival. They are food acquisition, human fears and
landscape preferences.

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54 3.1.1 Food Acquisition :
We all know that we cannot live without food and water. Nowadays,
obtaining food and water is comparatively easy,.i.e. We know where
exactly we can get food, its contents, and obviously, we know what we are
eating is not poisonous. But hundreds of years ago, the scenario was
different. Our ancestors had to face many problems finding food everyday.
While selecting food, tw o things are important. First one is obtaining
adequate amounts of calories, nutrients like sodium, calcium, and zinc etc.
Second one is making sure that you are not consuming dangerous levels of
toxins, which can result in death. (Rozin & Schull, 1988). To reach this
goal, activities like searching for food; recognizing, taking, handling,
eating it; and digesting it to absorb its nutrients are required. Species that
regularly eat both plants and animals are called omnivores. They eat many
kinds of foods —plants, nuts, seeds, fruits, meats etc. It increases the
probability of them consuming poison, because toxins are widespread
throughout the plant world. Toxins in plants are bad for animals who
consume them, but not for plants which are poisonous, because T oxins
help plants defend themselves from predators.
As food is our basic need, people spend more money on food than other
things. Human infants get all the needed calories from their mothers milk.
This prevents them from consuming fatal toxins until they can secure food
on their own. Humans (even rats!) have evolved taste preferences for
sweet foods; Sweet foods contain rich sources of calories (Birch, 1999;
Krebs, 2009). For example, honey has the highest caloric value, and it was
the most highly preferre d food when a study of food preferences was done
among Hadza hunter - gatherers of Tanzania. (Berbesque & Marlowe,
2009). Even newborn human infants show a strong preference for sweet
liquids. Humans dislike sour, bitter food which is likely to contain toxi ns.
(Krebs, 2009).
Rats and humans have an adaptation known as neophobia - a strong
aversion to new foods. Rats generally have new and unfamiliar food only
in very small doses, and they eat the new foods separately, and not
together. If the new and unfami liar food is consumed in small amounts
and separately, the rats get a chance to learn what makes them sick, and
they can avoid deadly overconsumption of poisons (Birch, 1999).
Do you feel like drinking your soup even after you see a dead fly in your
soup bowl?. According to the phenomenon we are going to study now,
no. Disgust is an emotion which generally involves feelings of revulsion,
nausea. It strongly motivates us to withdraw from the disgust -producing
stimulus (In this case, soup bowl with a fly in it).The emotion of disgust is
a hypothesized adaptation which acts as a defense against microbial attack
and protects people from the risk of disease (Curtis, Aunger, & Rabie,
2004; Oaten, Stevenson, & Case, 2009). If the emotion of disgust is an
evolved defense against disease, there are some predictions. First one is
that disgust should be evoked most strongly by substances which carry
diseases. The second is that these disgust elicitors should be culturally munotes.in

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55 Major Aspects of Evolutionary Theory: Survival And Mating- I universal. A third prediction is that disgust should activate the immune
system. Empirical resources support the first two predictions (Curtis &
Biran, 2001). Foods like rotting flesh, dirty food, bad -smelling food, food
leftovers, moldy food, a dead insect in food, and witnessing food
preparation by someone with dirty hands are found very disgusting in
people from various cultures. There are some gender differences found as
well. Women find images showing disease carrying objects to be more
disgusting than men do, and they perceive that the risk of di sease is higher
from those objects as compared to men. The reason could be that women
typically take care of their infants and children. They need to protect them
from disease, as well as themselves (Curtis et al., 2004).
Some women experience increased sensitivity and nausea towards some
food items during the first three months of pregnancy. It is called
pregnancy sickness or morning sickness. According to Profet (1992),
pregnancy sickness is an adaptation. It prevents mothers from consuming
toxins which can be harmful to the baby in the womb. Plants indicate their
toxicity with chemicals. For example, cabbage, cauliflower etc. have a
strong taste that comes from allylisothiocyanate (Nesse & Williams,
1994). We find these chemicals bitter, unpleasant —adap tations that help
us to avoid consuming toxins. If pregnant women consume such types of
foods, they are more likely to vomit. But here, vomiting is good as it
prevents the toxins from entering the mother’s bloodstream (Profet, 1992).
Mostly, foods which a re raw - uncooked have high levels of fiber. But
They provide few levels of calories when the efforts to chew, digest them
are considered. Cooking makes fibrous fruits, tubers, and raw meat more
easily digestible. It also frees up energy and kills microorga nisms that
could be toxic to humans. Cooking hypothesis is given by Richard
Wrangham. According to this hypothesis, the invention of fire and ability
to cook gave the key evolutionary momentum for the evolution of
extraordinarily large human brains. Follow ing evidence supports
Wrangham’s cooking hypothesis - 1) Cooking food increases its net
energy value. 2) Cooking makes food easily digestible. 3) cooking is
universally found in humans 4) The calories required by the human brain
to function are not adequat ely provided by fibrous fruits and other raw
foods. 5) If consumed raw food diets exclusively, humans progress poorly
and many women lose the ability to reproduce.
In our daily life, we eat spicy food very often. Not just in India, it is
similar worldwide . Why are we so concerned about spices? According to
the antimicrobial hypothesis, spices kill or hinder the growth of
microorganisms. They also prevent the production of toxins in the foods.
Thus it avoids falling ill or being poisoned by the foods we eat (Sherman
& Flaxman, 2001). According to evidence, some spices are very powerful
in killing the bacteria in the food, for example, onion, garlic, oregano etc.
(Sherman & Hash, 2001). This hypothesis does not say that humans have a
specialized evolved adap tation for using spices, but it could be that people
found that they were less likely to be ill after eating leftover food cooked
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56 For at least 24 million years, primates have been eating fruit. Most
primates such as chimpanzees, orangutans, an d gibbons are mainly
frugivorous. Frugivorous means fruit is the mainstay of their diet. The
ripest fruits are greatly preferred. They have high amounts of sugar and
ethanol. Primates including human beings have been consuming
For millions of years primat es, including humans, have been consuming
low levels of ethanol by eating ripe fruit. According to the frugivory by -
product hypothesis, the human fondness for consuming alcohol is not an
adaptation. Rather it's a by -product of adaptive liking for ripe frui t
(Dudley, 2002; Singh, 1985). Alcohol has a different taste, unique odor
and it is generally associated with color and fragrance of ripe fruits (Singh,
1985). Alcoholism in the contemporary world is likely a maladaptive
consequence of the overindulgence o f these frugivorous adaptations.
We know that our ancestors were hunters - they used to kill animals for
food. Humans eat far more meat when compared to other primate species.
For thousands of generations, Meat has been a key aspect of the human
diet. It i s found that modern tribal societies hunt as a major method for
obtaining food. For example, the Aka Pygmies are found in the tropical
rain forests of the Central African Republic.They spend about 56 percent
of their subsistence time hunting and 17 percen t of their subsistence time
in processing food (Hewlett, 1991).
Sharing food is a strategy of courtship, an indicator of closeness of
relationships and means for adjustment after a conflict (Buss, 2003).
Failure to provide food can result in a male losing his status in the group
(Hill & Hurtado, 1996; Holmberg, 1950). In Ganda and Thonga tribes in
Central Africa, it is common for women to get divorce from husbands
who fail to provide food (Betzig, 1989). Various cultures, religions and
myths revolve aroun d stories of food and food is frequently used as
metaphors (Lakoff & Johnson, 1980).
3.1.2 H uman Fears :
All of us have experienced fear and anxiety in our life. They signal danger
on specific occasions (Such as seeing a snake in the front yard) . All
habitats involve hostile forces that are barriers to human survival. But
humans have evolved different types of specific fears in order to avoid
these dangers. The adaptive reason for human fear is that they cause us to
deal with the source of danger, helping us to survive. (In this case, running
away from the snake and reaching a safe place).
According to Marks (1987) and Bracha (2004), there are six ways in
which fear and anxiety can protect us. They are freezing, fleeing, fighting,
submission or appeasement , fright and fainting.


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57 Major Aspects of Evolutionary Theory: Survival And Mating- I Table 3.1 Defenses and their explanation Sr. No Defenses Explanation 1 Freezing This response helps individuals to assess the situation and to hide from the predator. This can sometimes avoid an aggressive attack. 2 Fleeing This type of response takes an individual away from specific threats. For example, after seeing a snake, running away from the snake may be the safest, easiest way to avoid a snake bite. 3 Fighting This may include attacking, bashing or hitting
the predato r which can cause it to flee or
destroy it. For example, killing a snake with a
stick. It is assessed whether the predator can be
successfully repelled.For example, killing a
spider is much easier than killing a hungry bear. 4 Submission or appeasement: Generally, this response works when the threatening being is a member of one’s own species. For example, Chimpanzees perform submissive greetings to the alpha male usually to prevent a physical attack. The same could be true for humans. 5 Fright In this response the person “plays dead” by becoming muscularly immobile. The adaptive advantage of this response takes place during circumstances where fleeing and fighting will not work. For example, if the predator is very fast and strong. Predators are sensitive to movement of the potential prey and they sometimes lose interest in a prey that is not doing any movement for a while (Moskowitz, 2004). The predator might loosen its grip after this response, opening an opportunity for prey to escape from the situation. 6 Faint Losing consciousness to indicate the attacker that one is not a threat, is the defense of fainting. The hypothesized function of fainting after seeing blood or a sharp weapon is that it helps warfare noncombatants (like women and children) to signal adversaries that they are not an immediate threat and they can be safely ignored. Therefore, fainting might have munotes.in

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58 increased their chances of surviving violent conflicts. If this hypothesis is correct then it could be assumed that women and children would be more likely than men to faint after seeing blood, and there is evidence which strongly supports this prediction (Bracha, 2004).
These six behavioral responses to acute threat are adaptively patterned and
they generally take place in a predict able sequence (Bracha, 2004). First
response is to freeze, allowing a person to avoid detection and to plan how
to escape (Moskowitz, 2004). Next response could be fleeing, if you see a
bear coming to you. But if that too is unsuccessful, the next respons e is to
fight. If there is no chance of fleeing or fighting, one may respond by
frighting, i.e. playing dead. This sequence of defenses also occurs in most
mammalian species (Bracha, 2004).
Fear has a predictable set of evolved physiological reactions as well
(Marks & Nesse, 1994). A hormone called Epinephrine is produced by
fear. It helps blood clotting so that one can sustain a wound. (For example,
after having a fight with a bear). It acts on the liver and releases glucose so
that muscles can get energy to fight or flight. blood flow increases, it gets
diverted to muscles. People breathe more rapidly so that oxygen supply to
the muscles increases. All these physical reactions help our body to deal
with the danger.
Predators have been a threat to human su rvival throughout human
evolutionary history. For example, animals like lions, tigers, leopards and
crocodiles etc. (Brantingham, 1998). We are more likely to develop fears
of dangers from our ancestral environment than of dangers in the current
environmen t. For example, snakes are not a big problem in urban cities,
but automobiles are. That is, there are more chances of car accidents in
urban cities than snake bite. But still, people from cities may go to
psychiatrists with fear of snakes rather than fear of cars.
These specific fears tend to emerge at a time when the danger would have
been encountered (Marks, 1987). For example, fears of heights and
strangers take place when infants are about six months old. At this time
only, infants start to crawl away f rom their caretakers (Scarr & Salapatek,
1970). Crawling increases the risk of contact with dangerous falls, and
encounters with strangers, thus the emergence of these fears at this time
coincides with the onset of the adaptive problems. There are other ki nds of
fears emerging at a specific time. For example, separation anxiety peaks
between nine and thirteen months of age (Kagan, Kearsley, & Zelazo,
1978). Around age two, a child tries to extensively explore its
environment and at this time, animal fears e merge. The fear of being in
public places or places from where the escape might be difficult is called
Agoraphobia. It emerges as the young individual leaves the home base
(Marks & Nesse, 1994). The developmental timing of the coming of fears munotes.in

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59 Major Aspects of Evolutionary Theory: Survival And Mating- I tends to corr espond accurately to the onset of different adaptive problems
i.e. different kinds of threat to an individual's survival.
There are some fears which show clear sex differences. Adult females are
more likely than males to develop fears, phobias of snakes, spiders. In two
experiments with eleven months old, Rakison (2009) found that this
gender difference emerges in infancy. Women show more fear of events
in which they might get injured such as robbery, assault, burglary, rape,
car accidents (Fetchenhauer & Buunk, 2005). Men are more likely to
experience these threats to survival than women, with the exception of
rape. According to Fetchenhauer and Buunk, sexual selection has created
risk- taking strategies in men order to obtain status, resources and matin g
chances but in women the strategies are more cautious as they need to
protect their offspring (Campbell, 2013).
Table 3.2 shows some common human fears with hypothesized adaptive
problems for which they might have evolved (Nesse, 1990).
Table 3.2 Common fears with the adaptive problems Sr. No. Types of fears Adaptive problem 1 Fear of snakes and spiders Receiving a poisonous bite 2 Fear of heights Harm from falling from trees, cliffs etc. 3 Disease Contamination 4 Stranger anxiety Harm, damage from unfamiliar males 5 Social anxiety Loss of status, rejection from group
3.1.3 Landscape Preferences :
Where to live and how do we select a place to live? We will see how our
ancestors answered this question, in the upcoming theory. Good habitats
shall elic it strong positive responses and poor habitats shall elicit weaker
or negative responses. Evaluation of habitats, choosing a landscape to live
in can be a difficult process. Along with the current state of the landscape,
future states such as weather etc. are important. For safe movement
through the environment, a great deal of skills, knowledge is needed as
well.
According to Orians (1980, 1986), humans prefer to settle in environments
where there are abundant resources needed for survival, at the same tim e
avoiding environments which lack resources and are risky for survival.It is
widely believed that humans originated in the Savanna of Africa, and
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60 protection to sensitive human sk in from the harsh sun. It also provides a
refuge (places to hide) for escaping from danger. Studies of landscape
preferences support the savanna hypothesis. Many researches support the
conclusion that Humans prefer natural environments as compared to
human -made environments (Kaplan & Kaplan, 1982). A study by Kaplan
(1992) summarized findings from 30 different studies where participants
rated color photographs or slides on a five -point scale. The studies were
different, and included scenes from Western Aust ralia, Egypt, Korea,
British Columbia, and the United States. The participants were college
students, teenagers, Koreans and Australians. The conclusion of this study
was that natural environments are consistently preferred over human made
environments and pictures containing trees , vegetation are rated more
positively than environments without trees and vegetation (Ulrich, 1983).
Also, Ulrich (1986) found that individuals who are placed in a stressful
situation show less physiological distress when they a re seeing pictures of
nature scenes.
The savanna is a home to large terrestrial animals and primates like
baboons, chimpanzees. There are more opportunities for obtaining meat
than tropical forests, more vegetation for grazing and wide open
landscapes whi ch are favorable for nomadic lifestyle (Orians &
Heerwagen, 1992). The savanna hypothesis is supported by studies of
landscape preferences. We will look at one study in detail. In a study
participants from Australia, Argentina, and the United States did an
evaluation of a series of pictures of trees taken in Kenya. Each photograph
focused on a single tree and pictures were taken in similar daylight and
weather. The trees selected for study differed in four qualities - canopy
shape, canopy density, trunk heig ht, and branching pattern. Participants
from all cultures had similar judgments about the pictures. All had a
strong preference for savanna -like trees. They were also likely to dislike
skimpy and dense canopies (Orians & Heerwagen, 1992).
According to Ori ans and Heerwagen (1992), there are three stages of
habitat selection. Stage 1 is called as selection. When one comes across a
habitat or landscape, they need to decide whether to explore that place or
leave. These initial responses tend to be very affecti ve or emotional. Open
or completely closed environments are abandoned. If the reaction to stage
1 is positive then people enter stage 2. It can be called information
gathering. One tries to explore the environment to see its resources and
potential dangers . One may also check if there are places to hide, refuge.
According to a study by Kaplan (1992), people have a great fondness for
mystery at this stage. They may like paths that wind around a bend until
they are out of sight. Mapping includes evaluation of risk. Human beings
have poor vision at night so they need protection in darkness. A study
done with modern humans found that in their bedrooms, people prefer
keeping their bed in a way that they can see the door, as distant from the
door as possible and o n the location in the room toward which the door
opened (Spörrle & Stich, 2010). These results show adaptations against
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61 Major Aspects of Evolutionary Theory: Survival And Mating- I Stage 3 of habitat selection can be called exploitation. People decide if
they are staying in t hat habitat to acquire the benefits of the available
resources. The decision to stay or leave a habitat includes trade -offs. I.e.
The same place that has good availability of food may also have risk of
predators (Orians & Heerwagen, 1992). A craggy cliff can help one for
surveillance but it also has a risk of falling from that cliff. Each place has a
negative as well as positive side, so taking decisions at this stage requires
complex cognitive calculations.
3.2 MATE SELECTION In times of dating applicatio ns like tinder, do you wonder how our
ancestors selected their mates, i.e. sexual partners? As humans, we do not
have an equal desire for every individual of the opposite sex. Everywhere,
some people are preferred, some are not. From our ancestors, we hav e
received a certain set of mate preferences. Scientists have documented
evolved mate preferences in species other than men. They tried to find out
why animals select one particular mate, and not others. For example, we
will look at a study of a weaverbir d in an African village given by Collias
& Collias, (1970). When a female weaverbird enters in the proximity of a
male weaverbird, he shows her his nest by hanging on the nest upside
down from the bottom. He also vigorously flaps his wings. If this
impress es the female then she enters and examines the nest. (This
examination can last up to 10 minutes!) While she inspects the nest by
poking, pulling the material, he sings for her. If the female thinks that the
nest does not meet her standards, she leaves tha t nest and moves to another
male’s nest. Like this, a female weaverbird only selects a mate who is able
to build a superior nest. She addresses the issue of protecting and
provisioning her chicks.
In the act of sexual intercourse, male investment is minim al. But if the
female gets pregnant, it produces an obligatory, energy -consuming nine -
month investment by her. The activity of breastfeeding is only done by the
female. According to Triver’s (1972) theory of parental investment and
sexual selection, the se x which invests more in the children (which is
generally the female) will be more selective, discriminating about mating
(intersexual attraction).Here, parental investment can be defined as any
investment in the child by the parent which increases the offs pring's
chances of surviving at the cost of the parents ability to invest in other
offspring. Also, the sex that invests in lesser degree in children will be
more competitive for sexual access to the other sex which is high -
investing (intrasexual competiti on). When we talk about humans, females
have prominent obligatory parental investment. But in long term mating,
marriage, both males and females generally invest a lot in children. Thus
the theory of parental investment predicts that both females and males
shall be very choosy and discriminating.
The second topic is related to mate preferences as evolved psychological
mechanisms. How does one individual select a partner based on his/her
specific attributes or qualities? The process of selecting a mate invo lves
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62 factors. While selecting a mate, one requires psychological mechanisms.
These psychological mechanisms enable the addition of relevant attributes
and give each attribute correct w eight to make the final decision. There
may be some attributes that weigh more than others in taking the final
decision about choosing or rejecting a mate.
Charles Darwin (1981) proposed sexual selection. It acts to increase the
relative attractiveness o f people as potential mates. Traits that are
attractive to members of the opposite sex are called as sexually selected
traits. For example, height is a trait in males which is certainly attractive to
females. There are two main considerations about what ki nd of male a
female shall select for mating. First one is the quality of the genes of the
mate.i.e. better quality genes generally lead to better quality, more
successful offspring. The second consideration is males' capability and
desire to contribute to childcare directly or indirectly. In the case of males,
the considerations are different. In monogamous pair bonds, males shall be
sensitive to indicators of female fertility. Since they are spending a lot of
time only with a single female, the more fertil e she is, the better it is for
them. So if females are chosen based on their fertility, then younger
should be better than older as reproductive period of human females
terminates at menopause.
Almost universally, spousal age differences and studies of ma rriage data
show a similar pattern which is reported from mate choice preference
studies. The spousal age difference generally increases as the husband's
age at the time of marriage increases. The tendency for women to prefer
men whose status is better tha n their own is seen. This tendency leads to
hypergyny, i.e. women marrying up the social scale.
David Perrett and his colleagues did research on facial attractiveness.
Their results reveal that female preferences for specific male faces differ
during the m enstrual cycle. They used digitally morphed pictures and
showed that when women are in the ovulatory i.e. most fertile period of
their cycle, they favor a more masculinized version of a face. Women in
this phase are more attracted to faces which have featu res like larger and
squarer jaws, high cheekbones and salient brow -ridges. All these features
reflect high levels of the male hormone called testosterone. But during the
non-fertile stage of their cycle females show a preference for the
feminized versions of the same faces. One interpretation from this data is
that when women are likely to conceive they prefer cues that suggest good
genes but at other times they prefer cues which indicate the male is less
dominant and tends to invest in a relationship and p arenting. This
interpretation is well adjusted with questionnaire -based studies. These
studies suggest that women prefer heroes for one -night stands and altruists
as their long term mates, friends. Thus, one sex’s attempt to enhance its
reproductive perfor mance can influence the mating strategies of the other
sex.
There are consistent results that show that more symmetrical individuals
get higher ratings of attractiveness, are more aggressive and they perform
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63 Major Aspects of Evolutionary Theory: Survival And Mating- I attractive to females. Women report higher number of orgasm with more
symmetrical male partners. This high frequency of orgasm probably
results in high sperm retention, which has a direct effect on he male’s
fitness. Some evidence sugge sts that females are able to smell male
symmetry. Researchers Steve Gangestad and Randy Thornhill from t
asked women to rate the smell of T -shirts. These T - shirts had been worn
by symmetrical and asymmetrical men for two nights. The findings
revealed that women who were at or near the most fertile phase of their
cycle much preferred the smell of the T -shirts which were worn by the
symmetrical men. However, women who were in the infertile phase of
their cycle, and women who were using oral contraceptives r eported no
preference.
3.3 SEXUAL STRATEGIES Mating relationships can last for short, as well as long durations. Matings
of short duration can be called brief affairs, one night stands, etc. Both
sexes engage in long term and short term mating. People are likely to mate
with someone who is similar to them. Sexual strategies theory is given by
Buss and Schmitt (1993). According to this theory, human mating is
inherently strategic. Human beings seek specific mates to solve certain
adaptive problems that thei r ancestors faced during human evolution. Mate
preferences and mating decisions of human beings are hypothesized to be
strategic products of selection pressures which were operating during
ancestral conditions.
Here, the term strategy indicates the goal d irected and problem solving
nature of human mating behavior. Strategies can be defined as evolved
solutions to adaptive problems. It does not imply that the strategies are
consciously planned. According to sexual strategies theory, mating
strategies are co ntext dependent. They are highly sensitive to the temporal
context of long term versus short term mateships.
Summary of this theory is as follows - In history of human evolution, both
men and women have pursued short and long term matings, where
reproducti ve benefits were more than the costs. When pursuing a short
term sexual strategy, different adaptive problems must be solved, as
opposed to long term sexual strategy. There is fundamental asymmetry
between men and women in the minimum levels of parental in vestment.
Because of this, men allot a larger proportion of their total mating efforts
to short term mating, as compared to women. The reproductive
opportunities and constraints are different in men and women in long term
and short term mating. Thus, the a daptive problems that women must
solve while pursuing each strategy are different from the problems men
must solve, in these contexts. However some problems are common in
both sexes.
Historically, men have been inhibited in their reproductive success mainl y
by the number of the fertile women they can inseminate. This reproductive
constraint on men can be divided into four different types of problems.
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64 pursue a short term mating strategy . These problems are as follows - the
problem of partner number, the problem of identifying which women are
sexually accessible and fertile, and the problem of minimize investment
and commitment. Now we come to reproductive constraints on men which
they had to solve in order to effectively pursue a long term mating
strategy. These can be divided into four different types of problems. These
problems are as follows - The problem of identifying reproductively
valuable women, the problem of securing certainty in paternity, the
problem of identifying women with good parenting skills and those who
are willing, able to commit to a long term mating relationship. These
problems are summarized in table 3.3.
Historically, women have been inhibited in their reproductive s uccess, but
it is not by the number of men they can have sexual access to. Rather it is
mainly by the quality and quantity of the external resources that they can
assure for themselves and their offsprings and secondarily by the quality
of man’s genes. Th ese reproductive constraints can be divided into two
different problems. Historically, women had to solve these two problems
to effectively pursue a short term mating strategy. These problems are as
follows - the problem of immediate resource extraction and the problem of
assessing prospective long term mates. To effectively pursue a long term
mating strategy, women historically had to solve different adaptive
problems. They are as follows - the problem of identifying men who have
the capacity and show willin gness to invest resources in her and her
offspring for long term, the problem of identifying men with good
parenting skills, the problem of identifying men who are willing and able
to commit to a long term relationship with her, the problem of identifying
men who are able and willing to protect them from aggressive individuals
from the same species. These problems are summarized in table 3.4.
Men and women have evolved different psychological mechanisms, These
function to solve the adaptive problems, in or der to effectively pursue
short and long term matings. These psychological mechanisms and their
behavioral manifestations when combined with the temporal contexts,
form the evolved sexual stratgies of men and women. Sexual strategies
theory creates more de tailed, precise and numerous predictions than
previously given theories of human mating about adaptive problems that
are confronted by men and women in different mating contexts. In our
next unit, we will look at Women’s long -term mating strategies, men’s
long-term mating strategies and Short -term sexual strategies across sexes
in detail.
Table 3.3: Mate selection problems faced by men Types of mating Mate selection problems faced by men Short term mating 1. Problem of partner number 2. Problem of identifying which women are sexually accessible munotes.in

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65 Major Aspects of Evolutionary Theory: Survival And Mating- I 3. Problem of identifying which women are fertile 4. Problem of minimizing cost, risk and commitment Long term mating 1. Problem of identifying reproductively valuable women 2. Problem of securing certainty in paternity 3. Problem of identifying women with good parenting skills 4. Problem of identifying women who are willing, able to commit to a long term mating relationship.
Table 3.4: Mate selection problems faced by women Types of mating Mate selection problems faced by women Short term mating 1. Problem of immediate resource extraction
2. Problem of assessing prospective long term mates Long term mating 1. Problem of identifying men who have the capacity and show willingness to invest resources in her and her offspring for long term 2. Problem of identifying men with good parenting skills 3. Problem of identifying men who are willing and able to commit to a long term relationship with her 4. Problem of identifying men who are able and willing to protect them from aggressive individuals from the same species.
3.4 SUMMARY Survival for our ancestors was not an easy task. They encountered many
problems during the process. These are called as probl;ems of survival.
We know that food is our basic need and we cannot live without food. Our
ancestors faced many problems to satisfy this basic need. They needed to
choose what foods can be safe for them and how they can get an adequate
number of calories from the consumption of food. Humans have different
types of adaptations such as neophobia - strong ave rsion to new foods,
pregnancy sickness, emotion of disgust etc. Alcoholism in today's world is
likely a maladaptive consequence of the overindulgence of frugivorous
adaptations. We also talked about how our ancestors consumed meat by
hunting animals and th e socio -cultural aspect of food. We also looked at
antimicrobial hypothesis and cooking hypothesis in detail.
We saw how fear and anxiety help us to survive. There are six defenses
such as freezing, fleeing, fighting, submission or appeasement, fright and
fainting which generally take place in a predictable sequence. There are munotes.in

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66 some common fears like fear of height, snakes, spiders, strangers etc and
they might have evolved for some hypothesized adaptive problems. Sex
differences are also seen in fear. Thou sands of years ago, humans needed
to choose a place to live and they had preferences for the same. They
preferred places with resources who are needed to live and avoided places
where there was risk to their survival. The three stages of habitat selection
are selection, information gathering and exploitation. We also looked at
the Savanna hypothesis in detail.
With the help of Trivers theory (1972) of parental investment and sexual
selection, we learned how humans might choose their mate. Various
studies helped us to understand how women's choice of mate may change,
depending on the period of their menstrual cycle. Sexual strategies theory
given by Buss ands Schmitt (1993) explained about long term and short
term sexual strategies by men and women and adap tive problems both the
sexes needed to deal with. These problems are different for both the sexes
but still there are some adaptive problems which are common in both, like
identifying a mate with good parenting skills. We are going to look at long
term and short term strategies in detail in our next unit. Men and women
have evolved different psychological mechanisms, which function to solve
these adaptive problems, in order to effectively pursue short and long term
matings.
3.5 QUESTIONS A) Write long answe rs:
a) Discuss in detail about food acquisition.
b) Explain in detail about human fears.
c) Discuss in detail about landscape preferences.
d) Write about mate selection in detail.
e) Explain in detail about sexual strategies.
B) Write short notes:
a) Mate selection problems faced by men and women.
b) Six defenses given by Marks and Bracha.
3.6 REFERENCES  Barkow, J. H., Cosmides, L., Tooby, J. (1992). The adapted mind.
Oxford University Press.
 Buss, D., Schmitt, D. (1993). Sexual strategies theory : An
evolutionary perspective o n human mating . Psychological Review,
100 (2), 204 -232. munotes.in

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67 Major Aspects of Evolutionary Theory: Survival And Mating- I  Buss, D. (2015). Evolutionary Psychology: The New Science of the
Mind. Pearson Education.
 Dunbar, R. , Barrett, L., and Lycett, J. (2007). Evolutionary
Psychology: A Beginner's Guide. One world.

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68 4
MAJOR ASPECTS OF EVOLUTIONARY
THEORY: SURVIVAL AND MATING - II
Unit Structure
4.0 Objectives
4.1 Women’s long term mating strategies
4.1.1 The content of women’s mate preferences
4.1.2 Context effects on women’s mate preferences
4.1.3 How women’s ma te preferences affect actual mating behavior
4.2 Men’s long term mating strategies
4.2.1 Theoretical background for the evolution of men's mate
preferences
4.2.2 The content of men’s mate preferences
4.2.3 Context effects on men’s mating behavior
4.2.4 Effect of men’s preferences on actual mating behavior
4.3 Short term sexual strategies across sexes
4.3.1 Theories of men's short term mating
4.3.2 Women’s short term mating
4.3.3 Context effects on short term mating
4.4 Summary
4.5 Questions
4.6 References
4.0 OBJECTIVES After studying this unit you should be able to:
 Understand long term mating strategies of women
 Know men ’s long term mating strategies
 Study the context effects on men’s and women's mating preferences
 Study how men’s and women’s mate preferences affect actual mating
behavior
 Understand short term sexual strategies of men and women
4.1. WOMEN’S LONG TERM MATING STRATEGIES In our last unit, we understood the concept of mate selection and sexual
strategies. In the next section, we will look at women’s long term mating
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69 Major Aspects of Evolutionary Theory: Survival And Mating- II 4.1.1 The Content of Women’s Mate Preferences
Preference for Economic Resources :
Females prefer males who can offer them resources, from ancient times.
The evolution of this preference is a pre valent basis for female choice. A
study was done by Yosef (1991) about gray shrike birds living in the
Negev Desert of Israel. Just before breeding season, male shrikes begin
collecting things like food and feathers, pieces of clothes etc. They impale
these items on thorns etc. in their territory. Female shrikes then scan the
available males and they then choose to mate with those with the largest
collection of items. It was found that female shrikes totally avoided males
without resources.
In case of hum ans, this evolution of female’s preference for a long term
mate with resources would have required two prerequisites - 1) resources
would have to be incremental , defensible, and controllable by males
during human evolutionary history.2) Men would have to differ from each
other in their possessions and their willingness to invest such possessions
in a woman and her children. In human evolutionary history, most women
could gather better resources for their offsprings from a single spouse than
from many tempo rary sex partners. Men provide for their wives and
offsprings to a large extent, as compared to other primates. In other
primates, males generally do not share their food with their mates, so
females need to acquire their food on their own (Smuts, 1995).Bu t in
humans, men supply food, find shelter, defend their territory, etc. They
protect and tutor their children, transfer their status which helps the child
in forming reciprocal alliances in future. It is very unlikely for a women to
get these benefits fro m a temporary sex partner. This stimulated the
evolution of women’s preferences for men with resources. But in order to
know a man's possession of needed resources, women need some cues.
We will look at them in detail -
Preference for good financial prospe cts:
Many studies show that modern U.S. women value economic resources in
mates significantly more than men do. A large cross cultural study was
done with 10,047 individuals of thirty -seven cultures on six continents and
five islands (Buss et al., 1990). Results revealed that women from all
continents, all political systems, all racial and religious groups, and all
systems of mating gave more value than men on good financial prospects.
Women value financial resources about twice as much as men. Women
acros s the world wished for financial resources in marriage partners more
than men. These results showed extensive cross -cultural evidence which
supports the evolutionary basis for the psychology of human mating. Even
in Hadza of Tanzania, which is a hunter gat herer society, it was seen that
women give more importance to man’s foraging abilities —mainly his
ability to hunt and provide meat (Marlowe, 2004). This sex difference is
also see in modern forms of dating such as speed dating and mail -order
brides. A stu dy of the mate preferences of mail -order brides from
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70 women looked for husbands who had status and ambition - which are two
main correlates of resource acquisition (Minervini & McAndrew, 20 06).
Women also place significant value on intelligence in long term mates
(Buss et al., 1990; Prokosch, Coss, Scheib, & Blozis, 2009) as it is a
quality which highly predicts income and occupational status (Buss,
1994b). All these researches done with dif ferent people, different methods,
in different time periods support the hypothesis that women have evolved
a powerful preference for long -term mates with the ability to provide
resources.
Preference for High Social Status :
Among various cultures , like M elanesians, the early Egyptians,
Sumerians, the Japanese, and the Indonesians there were people called
“head men” and “big men” . They enjoyed power and recourse privileges
of prestige. The term big man is found in Sanskrit, Hindi and many
Dravidian langua ges. Women show willingness for men who have a high
position as social status indicates the control of resources. Higher status is
associated with better food territory and health care. Greater social status
gives such children social opportunities which a re missed by the children
of lower -ranking males. U.S. women give more importance to education
and professional degrees in mates. These characteristics are strongly
linked with social status.
Preference for Somewhat Older Men :
In the animal kingdom, youn g male baboons must mature before they are
good to enter the upper ranks in their social hierarchy. Human adolescents
generally don't have the respect, status, or position of more mature men.
For example, in all thirty -seven cultures included in the intern ational study
on mate selection, results revealed that women preferred older men. On
average in all cultures, women prefer men who are around three -and-a-
half years older. But the question arises that why do women prefer
somewhat older men but not much old er men. The answer may lie in the
problems developing in much older men. Much older men are more likely
to be infertile, females getting pregnant with them are more likely to
experience pregnancy problems and their children are at increased risk of
genetic abnormalities (Spinelli, Hattori, & Sousa, 2010). Things that
change with age shall also be considered to understand why women value
somewhat older mates. Access to resources is one of the most consistent
changes. In current societies, income tends to i ncrease with age (Jencks,
1979). In traditional societies also, part of this linkage can be related to
physical strength and hunting skills as physical strength increases in men
as they get older. Thus women's preference for somewhat older men may
come fro m our hunter gatherer ancestors.
Preference for Ambition and Industriousness :
Hard work is one of the best predictions of past and anticipated income
and promotions. People who say they work hard and their spouses agree
that they work hard get greater le vels of education, status, and higher
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71 Major Aspects of Evolutionary Theory: Survival And Mating- II compared to those who failed to work hard. As compared to lazy,
unmotivated men, industrious and ambitious men secure a higher
occupational status (J encks, 1979; Kyl -Heku & Buss, 1996; Lund,
Tamnes, Moestue, Buss, & Vollrath, 2007; Willerman, 1979). In the
majority of cultures women give importance to ambition and industry
more than men do. Evidence from cross -cultural and cross -historical
studies supp orts the main evolutionary expectation that women have
evolved a preference for men having signs of the ability to obtain
resources and contempt for men who lack ambition leading to resources.
Preference for Dependability and Stability:
In the worldwide s tudy on mate selection it was found that dependable
character and emotional stability or maturity are the second and third most
highly valued characteristics. These characteristics are valued by women
worldwide for two reasons. First reason is that they ar e reliable signals
that over time, resources will be provided consistently. Second reason is
that men who don't have dependability and emotional stability give in an
odd way and impose heavy emotional and other costs on their mates
(Buss, 1991). They are l ikely to be self -centered, possessive and show
higher -than-average sexual jealousy. They tend to be verbally and
physically abusive, display inconsiderateness (Buss & Shackelford,
1997a). All these results indicate that these men will fail to channel
resou rces consistently over time. Women give importance to dependability
and emotional stability to get the benefits that a mate can supply them
consistently over time.
Preference for Height and Athletic Prowess:
Women may experience physical domination from l arger, stronger males,
which can lead to injury, sexual domination. These situations surely
occured somehow regularly with our ancestors. Studies of non -human
primates showed that males have physically and sexually dominated
females. One advantage of long term mating for women is the physical
protection a man can offer. Cues that indicate the solutions to the problem
of protection are man’s size, strength, physical and athletic ability. Short
men are judged as undesirable by women for short term or long ter m
mating (Buss & Schmitt, 1993). In contrast, tall, physically strong and
athletic partners are found very desirable by women (Hughes & Gallup,
2003). The problem of protection from other aggressive men is solved by
women by preferring a mate who has the s ize, strength, and physical
capability to protect them. These physical qualities are also solutions to
other adaptive problems like obtaining resources and genes for good
health,as tallness is linked with status, income, symmetrical features, and
good heal th (Brewer & Riley, 2009).
Preference for Good Health: Symmetry and Masculinity :
Mating with an unhealthy person would have posed adaptive risks for our
ancestors. An unhealthy mate would have a higher risk of becoming
impaired, resulting in failure to p rovide food protection, health care, and
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72 transfer of communicable diseases by the unhealthy mate. An unhealthy
mate might infect the children and there can be risk of passing on gen es
for poor health to children. Facial and body symmetry is an important
health cue reflecting one’s ability to withstand environmental and genetic
stressors. Thus females are hypothesized to have evolved a preference for
males who have physical evidence o f symmetry. It may have genetic
benefits as well. Facially symmetrical individuals get high scores on tests
of physiological, psychological, and emotional health (Shackelford &
Larsen, 1997). Another health cue might come from masculine features.
Men are l ikely to have longer, border lower jaws, stronger brow ridges,
prominent cheekbones as a result of hormones such as testosterone. In a
study, results revealed that women generally preferred faces that were
more masculine -looking than average (Johnston, Hag el, Franklin, Fink, &
Grammer, 2001). Vocal masculinity is found to be attractive by women
(Feinberg, DeBruine, Jones, Little, 2008). According to Johnston,
masculine features are signals of good health. High levels of testosterone
compromise immunity. On ly healthy males can produce high levels of
testosterone and less healthy males must suppress their testosterone
production .Thus healthy males produce more testosterone. If this
argument is correct then women’s preference for masculine faces is a
preferen ce for a healthy male. We can summarize from the evidence that
women give importance to health in mate selection.
Love and Commitment :
Women have faced the adaptive problem of choosing men who show
willingness to commit the resources to them and their c hildren. Resources
can be observed directly but commitment cannot. Thus to test one's
commitment, looking for cues that indicate future channeling of resources
is required. One of the main cues to commitment can be love. Acts of
commitment are most centra l to love according to men and women. These
acts are giving up romantic relationships with others, the decision of
marriage, and showing a desire to have children with this person. When
these acts of love are performed by a man, they show his intention to
commit resources to one woman and her future children. Fidelity is one
component of commitment. It is remaining faithful to a partner when not
physically together. It is commitment of sexual resources to a single
partner. Emotional support is another facet of commitment. These acts are
seen as essential to love and they indicate the commitment of genetic,
economic, emotional and sexual resources to one person. Thus it is
predicted that women give importance to love while choosing long -term
mates.
Preferenc e for Willingness to Invest in Children:
Measuring men's willingness to invest in children is an adaptive problem
that women face when selecting a long -term mate. Its important as men
sometimes look for sexual variety and they may divert their efforts towa rd
other women. Another reason is that men evaluate if they are the actual
genetic father of the child and are likely to withhold investment if they
know or suspect that the child is not their own (La Cerra, 1994). A study munotes.in

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73 Major Aspects of Evolutionary Theory: Survival And Mating- II done by La Cerra (1994) suggests that women prefer men who show a
willingness to invest in children as marriage partners. They have a certain
preference and attraction for men who show a willingness to invest in
children.
Preference for similarity:
Both women and men show strong prefe rences for mates who have similar
values, worldviews,political orientations, and intellectual level.
Individuals who are similar on above mentioned characteristics date
(Wilson, Cousins, & Fink, 2006) and get married (Buss, 1985) much more
often than thos e who are dissimilar. This phenomenon is known as
homogamy. Similarity has benefits like emotional bonding, cooperation,
communication, mating happiness. It leads to lower risk of breaking up,
and probably increased survival of children (Buss, 2003; Cast ro, Hattori,
& Lopes, 2012).
Additional Mate Preferences: Kindness, Humor, Incest Avoidance,
and Voice :
In long term mates, traits of kindness, altruism, and generosity are highly
valued by women (Barclay, 2010; Phillips, Barnard, Ferguson, & Reader,
2008). Women prefer men who have a good sense of humor as long term
mates (Buss & Barnes, 1986; Miller, 2000). Incest avoidance is one of the
main preferences. Reproducing with genetic relatives is known to create
“inbreeding depression,”. It can lead to havi ng a child with more health
problems, lower intelligence because of the expression of deleterious
recessive genes. Human beings have strong incest -avoidance mechanisms.
for example, emotion of disgust at the thought of having sex with a sibling
(Fessler & Navarrete, 2004; Lieberman, Tooby, & Cosmides, 2003). Many
studies support the hypothesis that women find a deep voice specifically
attractive in a potential mate (Evans, Neave, & Wakelin, 2006; Feinberg et
al., 2005b; Puts, 2005). Reasons for ethe same co uld be that deep voice
signals sexual maturity, larger body size, good genetic quality, dominance
or all of the above.
4.1.2 Context Effects on Women's Mate preferences :
We saw many preferences that women have about long term mates. They
are not predicted to operate blindly. In fact, women's mate preferences are
context dependent. Let us understand the same in detail.
Effects of Women’s Personal Resources on Mate Preferences:
According to the structural powerlessness hypothesis, women are
generally exclud ed from power and access to resources, which are largely
controlled by men. Therefore women seek mates who have power, status,
and earning capacity. They try to get married in higher socioeconomic
status because it gives them access to resources. Men do no t give
importance to economic resources in a mate as much as women. It is
because they already have control over these resources (Buss & Barnes,
1986; Eagly & Wood, 1999). But it is seen that though women in the U.S. munotes.in

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74 are professionally and economically suc cessful, they value resources in
men. It was also seen that women who were financially successful,
showed a stronger preference for high -earning men as compared to women
who are less financially successful. This is contrary to the structural
powerlessness hypothesis. (Buss,1989a). Evidence found that these results
failed to support the structural powerlessness hypothesis, but they directly
contradict it.
The Mere Presence of Attractive Others - Mate Copying:
When an individual's choice of potential mate is a ffected by the preference
or mating decisions of others. It's called mate copying. This phenomenon
is previously documented in species like birds and fish (Dugatkin, 2000;
Hill & Ryan, 2006). Now it's seen in humans as well. Two studies
revealed that when a man was surrounded by women, he was judged to be
more attractive as compared to when he was standing alone (Dunn &
Doria, 2010; Hill & Buss, 2008a).
Effects of Temporal Context on Women’s Mate Preference:
A mating relationship can last for longer or sho rter duration. Findings by
Buss and Schmitt (1993) suggest that temporal context matters a great deal
for women. It leads to shifts in their preferences, depending on whether a
marriage partner or a casual sex partner is searched for (Schmitt & Buss,
1996) . A study revealed that women highly valued warmth and
trustworthiness in a long -term mate, but to a lesser degree in a short -term
mate ( Li and Kenrick, 2006).
Effects of Women’s Mate Value on Mate Preferences:
A woman's mate value is her overall desirabi lity to men. A female’s
physical attractiveness and youth signal her mate value. As a result,
women who are more physically attractive and young have more mating
options and they can be choosy in their selection. These women specified
a longer list of trai ts they searched for in a potential mate than women who
were lower in mate value (Pawlowski & Dunbar, 1999a; Waynforth &
Dunbar, 1995). Women who were attractive showed a desire for higher
levels of masculinity, physical attractiveness, sex appeal, and phy sical
fitness. These studies concluded that women who are themselves higher in
mate value, show preference and seek men who are higher in mate value.
4.1.3 How Women’s Mate Preferences Affect Actual Mating
Behavior :
Though we prefer something, it does not mean that we always get what we
prefer. In this case, there are a limited number of highly desirable potential
mates. An individual's own mate value limits access to highly desirable
mates. For example, only highly desirable women are in position to attra ct
highly desirable men and vice versa. Sometimes parents and others
influence mating decisions regardless of personal preference. But still,
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75 Major Aspects of Evolutionary Theory: Survival And Mating- II decisions, or they would not have evolved. Many sources of evidence
indicate that preferences in reality do influence mating decisions.
Women’s Responses to Men’s Personal Ads :
Evidence is found from women's responses to personal ads posted by men
in newspapers. Men with higher levels of education, men who were
somewhat older, and men who offered more resources received greater
responses from women than did men who lacked these qualities.
Women’s Marriages to Men High in Occupational Status :
A study U.S.in the year 1910 revealed that the higher a man’s
socioeconomic status, the greater the possibility that he would actually
marry (Pollet & Nettle, 2007). Poor men were more likely to stay
bachelors, unable to attract women, maybe because they failed to fulfill
women’s desire for men with resources and st atus.
Women marriages to men who are older :
Women’s preferences for older husbands are reflected into actual
marriages to older men. Actual mating decisions of women go hand in
hand with their expressed preferences.
Effects of women's preferences on men's behavior :
Men are more likely than women to show off their resources , talk about
their successes, display money and brag about their achievements (Buss,
1988b; Schmitt & Buss, 1996). When men try to devalue their
competitors, they use tactics. They sugg est that the rival is poor, lacks
ambitions and is not likely to be professionally successful (Buss &
Dedden, 1990; Schmitt & Buss, 1996). The emotion of envy is more
experienced by men than women in response to mating rivals who have
better status and res ources (DelPriore, Hill, & Buss, 2012). Research
indicates that men are aware about women's preferences for resources,
they take actions to express what women want. A part of men’s behavior
can be predicted from women's preferences. It can be concluded fro m the
studies above that women’s mate preferences have an important impact on
their own mating behavior and also on the mating strategies of men. We
will have a look at men's long term mating strategies in detail in the next
section.
4.2 MENS LONG TERM MA TING STRATEGIES 4.2.1 Theoretical Background for the Evolution of Men’s Mate
Preferences :
In this section, we will talk about the following topics - why men would
marry and benefits of commitment and marriage. Another topic is
complexities related to the co ntent of men’s desires, and how selection
might have caused specific mate preferences in men.
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76 Why Men Might Benefit from Commitment and Marriage :
We know that many ancestral women needed reliable cues of male
commitment before consenting to sex,. Males wh o failed to commit might
have failed to attract any women at all. Another advantage of marriage is
an increase in the quality of the woman a male would be able to attract.
Men who are willing to provide long -term resources, protection, and
investment in of fspring are appealing to women. Thus men who are
willing to commit to the long term relationship have a greater range of
women to choose from. A third benefit is an increase in the chances that
the male is the father of the children a woman has. Males gain repeated
and generally exclusive sexual access through marriage. Without this
exclusive, repeated access, a man's certainty in paternity would be
endangered. A fourth advantage would have been an increase in the
survival of man’s offspring. In human evolu tionary history, children who
survive without fathers' investment might have suffered from the lack of
fathers teaching, and political alliances as both these things help to solve
problems in future. Another potential benefit is that increased reproductive
success of children accrued through paternal investment. Men also get
advantage from marriage by an increase in status. Males are not thought of
to have achieved true manhood until they have married in many cultures.
Men also get access to coalitional all ies through his wife’s family.
The Problem of Assessing a Woman’s Fertility or Reproductive
Value :
Ancestral men had to marry fertile women with the capacity to bear
children in order to be reproductively successful. A woman with the
ability to bear more children would have been better than women to be
reproductively successful. Men cannot directly observe women's
reproductive value. Selection of women as mates could only have
fashioned preferences for qualities which are observable, and which
reliably co rrelate with reproductive value. How do men determine
women's reproductive value or fertility?
Reproductive value is the number of children an individual of a given age
and sex is likely to have in the future. A woman who is fifteen years old
has a higher reproductive value than a woman who is thirty years old. This
is because the younger woman is likely to have more children in the future
than the older woman. But a fifteen year old might decide to not have
children in future and a thirty year old may hav e six. The main thing is
that reproductive value is the average expected future reproduction of an
individual of a given age and sex. Reproductive value is different from
fertility. Fertility is defined as actual reproductive performance, which is
measured by the number of viable children produced. In human
populations, fertility reaches a peak in the mid -twenties. The solution to
the problem of detecting fertility or reproductive value, is complex. The
number of children women are likely to have is not en coded in her social
reputation, and women may themselves lack direct knowledge of their
reproductive value. But ancestral men could have evolved adaptations
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77 Major Aspects of Evolutionary Theory: Survival And Mating- II correlated with underlying re productive value. Two observable cues are
women’s youth and her health (Symons, 1979; Williams, 1975). Old,
unhealthy women certainly could not reproduce as much as young, healthy
women can do. But which observable qualities of a woman might signal
youth and health? We will try finding answers to this question in the next
section.
4.2.2 The Content of Men’s Mate Preferences :
Like women, men show a desire for an intelligent, kind, understanding and
healthy partner (Buss, 2003). They also look for partners w ho share their
values and have similar attitudes, personality, and religious beliefs. But
ancestral men faced different types of adaptive mating problems than did
ancestral women, so today's men are predicted to have a different set of
mate preferences as adaptive solutions. One of the most powerful cues to
women's reproductive status is her age.
Preference for Youth :
Youth is an important cue as a woman’s reproductive value decreases
slowly as she moves past age twenty. By the age of forty, her reproducti ve
capacity is low and by fifty it's zero. This preference of men for youthful
partners is not limited to western world. This is seen in the case of
Nigerian, Indonesian, Iranian, and Indian men. That is, men universally
prefer younger women as wives. The strength of these preferences vary
from culture to culture.
Among Scandinavian countries men prefer their wives to be only one or
two years younger but men in Nigeria, Zambia prefer their wives to be six
and a half and seven and a half years younger, resp ectively. A study about
personal ads in newspapers revealed that a man’s age has a strong effect
on what he desires. As men's age increases, they prefer women who are
increasingly younger than they are. Men in their thirties prefer women
who are roughly fi ve years younger, where men in their fifties prefer
women who are ten to twenty years younger (Kenrick & Keefe, 1992).
According to an evolutionary model, men do not desire youth but rather
features of women that are related to her reproductive value or fe rtility.
According to this perspective, when it comes to the age preferences of
adolescent males, teenage males shall prefer women who are slightly
older than them. It is contrary to the generally observed pattern of men
desiring younger partners. This i s because in the case of adolescents,
slightly older women have higher fertility than women of their own age or
women who are younger (Kenrick, Keefe, Gabrielidis, & Cornelius,
1996).
Teenage males at their youngest ages prefer women who are a few years
older than themselves. But as their age increases, men prefer women who
are increasingly younger than them. One explanation of men's desire for
younger women is that they are easy to control and are less dominant than
older women and men search for women wh o they can control. But this
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78 Another explanation is learning theory. As women are likely to prefer
men who are somewhat older, men may have received more reinforcement
for seeking dat es with younger women. But this explanation also fails to
explain the preferences of teenage males. They prefer older women
despite the fact that the interest is rarely reciprocated. Evolutionary
psychological explanation has received strong support from t he cross
cultural data. Men wish for younger women as over evolutionary time,
youth has regularly been linked with fertility. This theory explains two
facts that other theories don't focus on. The first one is that men desire
increasingly younger women as they themselves get older and second one
is that teenage males prefer women a few years older than they are, despite
the fact that such females don't often reward them for this interest.
But one thing is not explained by the evolutionary hypothesis. Men w ho
are fifty prefer women who are in their mid -thirties i.e. the actual age
preferences of older men are beyond maximum fertility. There are some
possible explanations. First, it may be difficult for older men to actually
attract dramatically younger women , and their preferences may reflect a
compromise among their ideals and what they can get (Buunk et al.,
2001). Second, large age differences may lead to less compatibility, more
marital conflict, and greater marital instability. Third, modern marriage is
likely different from ancestral marriage. In today's marriages, couples
spend a lot of time together, they socialize as a couple, and act as
companions. In hunter gatherer groups, ancestral marriages were more
likely to have divisions of labor, and women s pent most of the time
children and other women, and men spent their time hunting and
socializing with other men. Therefore, similarity and compatibility are
important in the functioning of modern marriages. This may have created
a change in men’s age prefe rences above the point of maximum female
fertility.
Evolved Standards of Physical Beauty :
Our beauty standards for females have cues to women’s fertility or
reproductive value. According to evolutionary perspective, beauty is in the
“adaptations' ' of th e beholder (Symons, 1995). For our ancestors,
observable evidence of a woman’s reproductive value were as follows - (1)
features of physical appearance, like full lips, clear and smooth skin, clear
eyes, shiny hair, body fat distribution and good muscle tone ; (2) features
of behavior, like bouncy youthful gait, high level of energy and an
animated facial expression. These are physical cues to youth, health and
thus also to fertility and reproductive value. Therefore they have been
hypothesized to be few main aspects of male standards of female beauty
(Symons, 1979, 1995).
Many universal cues that correspond with the evolutionary theory of
beauty are discovered by Ford and Beach (1951). Signs of youth (clear,
smooth skin) and signs of health (absence of s ores and lesions) are
universally considered attractive. Cues to ill health, older age, poor
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79 Major Aspects of Evolutionary Theory: Survival And Mating- II There are some universally undesirable cues like Ringworm, facial
disfigurement, and filthiness. The white of eyes around the iris - a super
white sclera is the main cue to health and it is considered as attractive
(Provine, Cabrera, & Nave -Blodgett, 2013). Length and quality of
women’s hair is cue to youth and health. A study revealed that hair length
and quality were strong cues to youth. Women who were young had high
quality, longer hair than older women (Hinsz, Matz, & Patience, 2001).
Another important element in judgment of attractiveness is skin quality. It
gives a cue to a woman's age and some info rmation about her lifetime
health (Sugiyama, 2005). Clear and unblemished skin indicates an absence
of parasites and skin -damaging diseases during development, and
probably good genes that can deal with disease and heal without infection
(Singh & Bronstad, 1997).
Femininity is also a cue to attractiveness (Gangestad & Scheyd, 2005) and
a meta -analysis showed that facial femininity is one of the strongest cues
to women’s attractiveness (Rhodes, 2006). Facial femininity involves cues
like large eyes, thinner jaws, small chin, high cheekbones, and full lips etc.
This female facial femininity seems to indicate reproductive value for the
following reasons. First, as a woman's age increases, her facial features
become less feminine. Also, facial femininity is rel ated to higher levels of
estrogen, the hormone in females that correlates with fertility (Schaefer et
al., 2006). Another reason is that facial femininity is related to health and
certain parts of disease resistance (Gray & Boothroyd, 2012). Even
feminine voices are found to be more attractive in women, providing cues
to youth (Collins & Missing, 2003; Feinberg et al., 2005a; Röder, Fink, &
Jones, 2013). Another correlate of female attractiveness is facial symmetry
(Gangestad & Scheyd, 2005; Rhodes, 2006) a nd symmetrical faces are
considered as healthier than less symmetrical faces (Fink et al., 2006).
Facial averageness is another quality linked with attractiveness. Long legs
are hypothesized to be a cue to biomechanical efficiency and health
(Sorokowski & Pawlowski, 2008).
Traditional theories of attraction have the assumption that standards of
attractiveness are learned by an individual gradually through cultural
transmission. Thus they do not emerge fully until an individual is three or
four years old (B erscheid & Walster, 1974; Langlois et al., 1987). But the
evidence by Langlois, Roggman, & Reiser -Danner (1990) challenged this
view. According to their study no training seems required for these
standards to emerge .Elements of beauty are not arbitrary or culture
bound. A study showed huge consensus about who is and who is not
considered as good -looking (Cunningham, Roberts, Wu, Barbee, & Druen,
1995).
Using neuroscience technology, it was found that the reward circuit -
pleasure center in the brain fails to become activated when men look at
male faces or typical female faces. But it is especially activated when they
look at attractive female faces. Thus beautiful female faces are
psychologically and neurologically rewarding for the men.
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80 Body Fat, Waist -to-Hip Ratio, and Body Mass Index :
Apart from facial beauty, features of the rest of the body provide cues to a
woman’s reproductive capacity. Standards for female bodily attractiveness
can vary from culture to culture. One such culturally variable standard is
the preference for slim versus a plump body build. In cultures where there
is scarcity of food, plumpness indicates wealth, health, and sufficient
nutrition during development (Rosenblatt, 1974).
During economic hard times, men prefer heavier women (Pe ttijohn &
Jungeberg, 2004). In cultures where abundant food is available, the
wealthy distinguish themselves by being thin (Symons, 1979). Though the
body weight preferences differ in cultures they are predictable, suggesting
context -dependent adaptations (Sugiyama, 2005, p. 318).
One preference for body shape that might be universal is the preference
for a particular ratio between the size of a woman’s waist and her hips
(Singh, 1993; Singh & Young, 1995). The waist -to-hip ratio (WHR) is
similar for boys and girls before puberty. A dramatic change occurs in
boys and girls fat distributions at puberty. Boys lose fat from their
buttocks and thighs, but in girls, due to the release of estrogen, fat is
deposited on their hips and upper thighs. Thus after pub erty, WHR in
women becomes significantly lower than men’s. Reproductively capable
and healthy women have WHR between .67 and .80, and healthy men
have WHR between .85 to .95.
WHR is a good indicator of the reproductive status of a woman . Women
who have lo wer ratios display earlier pubertal endocrine activity. Married
women with higher WHR have more difficulty getting pregnant.
Similarly, The WHR is also an accurate indicator of long -term health
status. Stroke, diabetes, hypertension, heart attack, and gall bladder
disorders are linked with the distribution of fat rather than the total level of
fat. Singh also found that WHR is a significant part of women’s
attractiveness. In many studies conducted by him, it was revealed that men
found women’s average figure more attractive than a thin or a fat figure.
There are differences in preferences for WHR based on long term and
short term sexual strategies. Men who are likely to pursue a short -term
sexual strategy have a greater preference for low WHR than men
follow ing a long -term mating strategy (Schmalt, 2006). Body mass index
(BMI) is another hypothesized cue to female body attractiveness. It is
calculated from an individual's weight and height. BMI and WHR are
positively correlated i.e. as WHR increases, BMI incr eases. Some Sex
differences are found in the importance given to physical appearance by
men and women. It was seen that men considered physical attractiveness
and good looks as more important as compared to women.
Do Men Have a Preference for Ovulating Wo men?
Ovulation is the time when the egg, released into the woman’s uterus to be
potentially fertilized by a sperm. Most nonhuman primate species exhibit
attraction to ovulating females (Puts et al., 2013). But in humans, the
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81 Major Aspects of Evolutionary Theory: Survival And Mating- II able to detect ovulating women (Symons, 1995). For example, women's
skin may glow , slightly lighten (Frost, 2011; van den Berghe & Frost,
1986), their voices may rise in pitch (Bryant & Haselton, 2009) during
ovulation. Studies also revealed that during ovulation, men perceive their
romantic partners to be more attractive (Cobey et al., 2013) and ovulating
women are touched more frequently in singles bars by men (Grammer,
1996). So we can conclude that there are some observable physical
changes in a women’s body when they ovulate —changes which are
known to be sexually attractive to men.
Ancestral men faced a unique paternity problem which was not faced by
other primate males, i.e. how to be sure of their paternity when ovulation
was concealed. Marriage potentially gave one solution (Alexander &
Noonan, 1979; Strassman, 1981). Following two mate preferences could
solve the problem for males - first one is desire for premarital chastity and
second one is the pursuit for postmarital sexual fidelity.
4.2.3 Context Effects on Men’s Mating Behavior :
Mens long term mating strategies are influenced by social, ecological, and
personal contexts. Most men give importance to youth and beauty, but not
all men are successful in achieving their desires. Some men lack the status
and resources that women want. They may face problems in attracting
such women and may have to settle for less than their ideal. Men who
have higher occupational status tend to marry women who are more
physically attractive as compared to men low in occupational status. Such
men who have high status and income are aware about their ability to
attract more desirable women.
Contrast Effects from Viewing Attractive Models:
Many standards of beauty are not arb itrary but they incorporate cues to
fertility and reproductive value. Advertisers use existing mate preferences
in order to be successful. They put a clear skinned and young woman with
regular features in a car advertisement because that exploits men’s evo lved
psychological mechanisms and it leads to sale of the car. But such media
images have a negative impact. A study revealed that men viewing
pictures of attractive women eventually rated their actual partners to be
less attractive as compared to men who had seen pictures of women who
were average in attractiveness (Kenrick, Neuberg, Zierk, & Krones, 1994).
Testosterone and Men’s Mating Strategies:
The hormone called testosterone (T) plays a main role in male mating
efforts – the time and energy spent to p ursue mates and besting same -sex
competitors (Ellison, 2001). Higher testosterone levels in males facilitate
male pursuit of females. These levels also increase after interaction with
an attractive woman (Roney, Mahler, & Maestripieri, 2003). But
maintaini ng high levels of testosterone can be high priced for men as it
can compromise immune functioning. Having a committed mating
relationship causes a reduction in testosterone in men but it is only when
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82 Men's mate preferences change as a result of their “mating budget.” Men
try to focus on necessities such as sufficient levels of physical
attractiveness on a limited mating budget. After these “necessities” are
fulfilled, they move to “luxu ries” such as creativity and personality traits.
4.2.4 Effect of Men’s Preferences on Actual Mating Behavior :
Men's mate preferences have an impact on actual mating behavior. Men
respond more often to personal ads given women who claim to be young,
physica lly attractive. This response of men to women’s personal ads gives
evidence that men act on their preferences. Men actually marry women
who are younger to them by around three years. These actual marriage
decisions by men confirm their preference for wome n who are
increasingly younger than them. Such men who are married to younger
women have higher reproductive success. Attracted women are visually
attended more by men as compared to women who are less attractive.
When men are interacting with attractive w omen, they lower their vocal
pitch into a more masculine range which appeals to women. Attractive,
young waitresses receive more tips from men (Lynn, 2009), and men
spend more money on engagement rings for younger brides than on older
brides -to-be. Women s pend more effort than men to enhance their outer
appearance to attract mates. These include wearing makeup, dieting, using
cosmetic surgery, etc. which suggests that women are responding to
men’s preferences. Women tend to demean their rivals by putting down
their physical appearance and calling them promiscuous. These tactics are
effective in displaying their rivals as less attractive to men, as they don't
follow the preferences which men have for a long term mate.
To summarize, women's behavior is like ly to be predicted by the
preferences expressed by men. So we can say that males' mate preferences
affect actual mating behavior of their own as well as of women.
4.3 SHORT TERM SEXUAL STRATEGIES ACROSS SEXES 4.3.1 Theories of Men's Short Term Mating :
Men are predicted to have evolved a greater wish for casual sex than
women. The reproductive benefit for men who successfully pursue short
term mating is an increase in the number of offspring produced. But there
are some potential costs of short term mating for men such as a risk of
contracting sexually transmitted diseases, acquiring a social reputation as a
“womanizer, (which would reduce their chances of finding a long term
mate). There are other disadvantages like reduction in the survival
chances of th eir children due to lack of paternal investment and protection;
experiencing violence from the jealous husbands or boyfriends of the
women if they were married or mated. There is also a risk of retaliatory
affairs by their wives and the possibility of a co stly divorce (Buss &
Schmitt, 1993; Daly & Wilson, 1988; Freeman, 1983). Ancestral men who
followed a short -term sexual strategy faced some adaptive problems. They
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83 Major Aspects of Evolutionary Theory: Survival And Mating- II women were fertile, a nd avoiding commitment. We have also found some
physiological, psychological and behavioral evidence for an evolved
short -term mating.
4.3.2. Women’s Short -Term Mating :
Testical size and differences in sperm insemination are some physiological
clues in me n, which suggest a long evolutionary history of sperm
competition. In this competition, sperm from two men inhabit a woman's
reproductive tract at the same time.
It seems unlikely that women would have frequently engaged in short -
term mating without gainin g some adaptive benefits. If they never
engaged in short term mating,men could not have evolved a strong wish
for sexual variety (Smith, 1984). If ancestral women willingly and
frequently were involved in short -term mating, it would refuse the
evolutionary logic if there were no advantages to women of doing so. In
reality there are cues starting with the physiology of the female orgasm
which suggest that ancestral women did engage in short -term mating.
The physiology of women’s orgasm gives one important c lue to an
evolutionary history of short -term mating. Function of women’s orgasm is
to get the sperm from vagina into the the cervical canal and uterus,
increasing the chances of conception. Women who have affairs are more
likely to be orgasmic with their a ffair partner as compared to their regular
partner (Buss, 2003). Results from some studies revealed that women are
specifically likely to get sexual orgasm with masculine and physically
attractive men. These are the qualities women generally desire in shor t-
term mating (Puts, Welling, Burriss, & Dawood, 2012). The behavioral
perspective suggests that women in most restrictive society sometimes
involve in extramarital sexual unions. Modern cultural and tribal evidence
does not suggest that women engage in mo nogamous long -term mating
strategy all of the time.
Hypotheses about the Adaptive Benefits to Women pursuing Short -
Term Mating:
There must have been some adaptive benefits associated with casual sex in
some situations, so that short term sexual psychology evolved in women.
There are five classes of benefits such as resources, genes, mate switching,
short -term for long -term mating goals, and mate manipulation (Greiling &
Buss, 2000). We will look at each of them in detail -
Resource hypotheses :
According to resource hypotheses, one advantage of short term mating is
resource accrual (Symons, 1979). Women could get involved in short term
mating for meat, services or goods. Smith (1984) gave the status
enhancement hypothesis of short -term mating. According to th is
hypothesis, women may increase social status among her peers and get
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84 They can also get different tangible and intangible resources through
short -term mating.
Genetic Benefit Hypot heses :
The benefits can be genetic as well. If a regular mate of a woman is
infertile or impotent then a short term mate might give a fertility backup to
help in conception. Genes of a short term mate might be superior than
regular mate, specifically if she has an affair with a healthy, high status
man, giving her child better chances for survival or reproduction (Smith,
1984). Having a child from a short term mate might give a women
different genes than those of her regular mate, increasing the genetic
diversity of her offsprings (Smith, 1984)
Mate Switching Hypotheses :
If a woman's husband stops providing her resources, starts abusing her,
declining his value to her as a mate, (Betzig, 1989; Fisher, 1992; Smith,
1984) then the ancestral woman might have advantaged from short term
mating. According to the mate expulsion hypothesis, engaging in a short
term affair would help the woman to get away from her long term mate.
Another form of this hypothesis suggests that a woman might also find a
man who is bet ter than her husband and may utilize a short -term encounter
as a way of “trading up” to a higher quality mate.
Short -Term for Long -Term Goals Hypotheses :
According to this hypothesis, women use short -term mating as a way to
assess and evaluate potential lo ng-term mates (Buss & Schmitt, 1993).
Involving into short term mating allows a woman to clarify the qualities
she wants her long term mate to have , and also to judge her compatibility
with a specific man (for example, sexual compatibility) and know any
hidden costs he might have ( for example, existing children).
Mate Manipulation Hypotheses :
According to this hypothesis, having an affair might enable women to get
revenge on her husband for his infidelity, possibly discouraging him from
future infidelity (Symons, 1979). A woman might be able to elevate the
commitment of her regular mate if he sees with evidence that other men
are seriously interested in her (Greiling & Buss, 2000).
Costs to Women of Short -Term Mating:
Women sometimes suffer more severe c osts as a result of short term
mating than men. Women have a risk of reducing their desirability as a
long term mate if they get renowned for promiscuousness, because men
value fidelity in potential wives.
Women having the reputation of being promiscuous s uffer from
reputational damage. According to Buss, (2013), woman suffer the
damage ot their status and reputation as a result of short term sex, more
than men. A woman engaging in exclusively short term sexual strategy is munotes.in

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85 Major Aspects of Evolutionary Theory: Survival And Mating- II at higher risk of physical and se xual abuse as she lacks a man to offer a
long term protection. A woman who is not married risks getting pregnant
in a search of causal sex and bearing children without the advantage of an
investing man. Such children would likely have been at higher risk o f
diseases, injury and death in ancestral times. There are some women who
-commit infanticide without the presence of an investing man. There is
also a risk of contracting sexually transmitted diseses from short term
mating. This risk is higher for women t han men per act of sex (Symons,
1993).
4.3.3 Context Effects on Short -Term Mating :
There are individual Differences in Short -Term Mating. Results obtained
from a study done by Greiling and Buss (2000) revealed that women who
engage in short term mating ha ve different perceptions of the advantages
of the same as compared to women who tend not to pursue short -term
mating. Findings supported many of the hypothesized benefits of extra -
pair mating, such as obtaining resources, securing good genes and
switching mates. Studies suggest that women engaging in a short -term
mating strategy might not dress more provocatively in general. but when
they are ovulating, they dress more provocatively. It was also found that
men who are likely to pursue a short term mating st rategy give more
attention to physically attractive women than more long -term oriented
men (Duncan et al., 2007)
There are some contexts which are likely to affect short term mating.
Differences in sexual strategy depend on different types of social, cultu ral,
and ecological conditions. Some such contexts affecting short term mating
strategy are father absence and stepfather presence, transitions across life
etc. One such context is sex ratio —a surplus of women are likely to
promote short -term mating in bot h sexes. Another important context is
mate value. Men who have higher mate value are more likely to pursue
short -term mating. Some studies show that women with a low WHR
(which is attractive) are a bit more inclined to pursue a short -term mating
strategy. They are also perceived as more sexually unrestricted by others.
Some personality characteristics also predict sexual strategy. Those who
have high levels of extraversion, low levels of agreeableness and
conscientiousness are more inclined to short -term ma ting. Those who have
high scores on narcissism, psychopathy and Machiavellianism are likely to
pursue an exploitative short -term mating strategy.
4.4 SUMMARY In this unit, we learned that sexual strategies can be long term as well as
short term. Initially, we looked at women’s and men’s long term mating
strategies. We understood the content of mate preferences, how it is
different for both the sexes and effects of context on mate preferences. We
also discussed the effects of men’s and women’s preferences o n their
actual mating behavior. There are short term sexual strategies of men and
women. We studied theories of men's short term mating and discussed five
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86 mating strategy. Finally, we s aw how context can have an important
impact on short term mating.
4.5 QUESTIONS A) Write long answers:
a) Summarize the content of women’s mate preferences.
b) Discuss - evolved standards of physical beauty.
c) Explain - Women’s short term mating.
B) Write short n otes:
a) Explain - context effects on women's mate preferences
b) Discuss how women’s mate preferences affect actual mating
behavior,
c) Theoretical background for the evolution of men’s mate preferences.
d) Write in detail - Men’s preference for youth.
e) Context effects on men's mating behavior and effects of men's
preferences on actual mating behavior.
f) Theories of men's short term mating and context effects on short
term matings.
4.6 REFERENCES  Barkow, J. H., Cosmides, L., Tooby, J. (1992). The adapted mind.
Oxford Univ ersity Press.
 Buss, D., Schmitt, D. (1993). Sexual strategies theory : An
evolutionary perspective on human mating . Psychological Review,
100 (2), 204 -232.
 Buss, D. (2015). Evolutionary Psychology: The New Science of the
Mind. Pearson Education.
 Dunbar, R . , Barrett, L., and Lycett, J. (2007). Evolutionary
Psychology: A Beginner's Guide. One world.

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87 5
PARENTING AND SOCIAL BEHAVIOR - I
Unit Structure
5.0 Objective
5.1 Parenting introduction
5.1.1 Maternal involvement and Paternal Involvement
5.1.2 Parent -offspring conflict
5.2 Kinship introduction
5.2.1 Theory of implicit and inclusive fitness
5.2.2 Empirical support for theory if implicit and inclusive fitness
5.3 Summary
5.4 Questions
5.5 References
5.0 OBJECTIVES After studying this chapter, the students will be able to:
 Understand evolutionary differences in maternal and paternal
parenti ng behavior
 Understand evolutionary reason behind parent -offspring conflict
 Understand kinship theory and its empirical basi
5.1 PARENTING INTRODUCTION According to evolutionary perspective, two of the primary jobs of any
human being are survival and re production. We have developed several
behaviors that aid in survival such as preference for certain types of food,
bodily reflexes, heightened attention to negative stimuli, etc. The term
survival in evolutionary psychology does not only refer to survival of the
person themselves but also survival of their species. Best way to ensure
survival of one’s species is via reproduction. According to Buss(2011), off
springs are primary vehicles carrying one’s genes. As such, behaviors
protecting one’s children beco me paramount. Collectively, these behaviors
can be called as parenting.
Parenting is an expensive task. Species that engage in parenting spend a
lot of time and resources into raising their off spring. The resources that
could have been spent on meeting more mates and producing more
children. Humans carrying young ones also put themselves at risk as they
cannot run immediately to save themselves, if a predator may attack. They
also have to roam long and far to fetch food for their young ones, leaving
the safety of their residence. This is the reason some species do not engage
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88 oysters. Humans are one of the rare species providing extensive care to
their babies. Several reasons contribute to this. First of all, humans cannot
produce as many off springs at one attempt, in a life time, as much as
oysters or cats or dogs do, for that matter. Second, human babies are born
quite helpless. They need care for multiple years after being born to ens ure
their survival. For example, a calf stands on its feet few hours after being
born. Whereas a human baby takes more than an year to start walking.
One of the puzzles that researchers studying humans tried to resolve for
several years was the gender dif ferences in parenting. All over the globe,
across different species, mothers seem to be investing much more heavily
in parenting than fathers. The reasons contributing to mating differences
are where parenting difference is also stemming from. Since severa l years,
traditionally mothers have been seen to be providing food and care
whereas fathers have been providing resources and protection. In ancient
societies, while fathers would go out hunting for meat, mother would stay
back with young ones and look aft er them. An interesting study conducted
recently found an pregnant women being involved in more ‘nesting’
behaviors such as organizing and de cluttering home(Anderson and
Rutherford, 2013).
5.1.1 Maternal involvement and Paternal involvement :
The two lea ding hypothesis that explain difference in maternal and
paternal care are:
1) Paternity uncertainty hypothesis
2) Mating opportunity cost hypothesis
Paternity uncertainty hypothesis:
Body structure of majority of the living beings is made such that females
of the species bear gestation and give birth to offspring whereas males
typically provide the seed / sperm for offspring conception via sex.
Therefore, a female is often 100% sure that the baby born is carrying her
genes. However for a male there is always a possibility that another male
has provided sperm for the baby. The issue of whether baby is carrying
one’s genes or not is important here as the task of survival makes it
necessary to ensure that one’s own genes are continued to live in order for
one’s species to survive. Everyone, whether male or female want to spent
their resources and care on their own child who is carrying their genes
instead of protecting genes of someone else.
Paternity uncertainty issue becomes more salient in mammals like humans
that involve internal fertilization. There is always a possibility that a
female’s egg is already fertilized when she comes in contact with male A,
or she may secretly mate with any other male while courting male A. As
such, it becomes quite costly for ma le A to provide their resources on a
child he isn’t sure is his own. As resources are limited, anything spent on a
rival’s child is snatching it away from one’s own child. It is like helping
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89 Parenting And Social Behavior - I one’s own genes. On the other hand, as mothers are always sure that the
child born is carrying their genes, they bear no uncertainty cost when
raising him/her. Thus, it is less profitable for fathers than mothers to spend
all their time and resources on a child. This hypothesis explain why
mothers are more heavily involved in childcare than father.
Mating opportunity cost hypothesis :
Mating opportunity costs are costs born as a result of spending time and
resources taking care of a child. These cos ts are missed opportunities to
produce another child due to being engaged with raising one child. Both
the genders suffer this loss. Mothers bear this cost by gestating, breast
feeding, looking after the baby whereas fathers pay it by being busy
keeping aw ay predators and fending for resources. As such neither of them
can produce another child while completing these tasks.
Further these costs tend to be higher for males than females. This is
because a human male has larger capacity to produce children than a
human female. This is because a male’s job in mating is to inseminate a
female. Once it is done, he does not have any other physically engaging
part to play in entire gestation. Thus, a male can produce as many child as
the number of times he can insemi nate a woman. This number can
possibly be very large. However for a female, since once they get pregnant
they cannot produce another child at least for next nine months, the
number of children she can produce is limited. In other words, the lost
mating opp ortunities as a result of being heavily involved in taking care of
a child are more for a male than a female. This is why they do not spend
100% of their time and resources in raising a child.
This hypothesis is supported by study of a fish species by Gro ss and
Sargent, 1985 (as cited in Buss, 2011). This fish species has a unique child
rearing practice wherein male fishes mark and protect their own territory.
A female fish lays her eggs in a territory she finds safe and thereafter it is
male fish’s job to protect the eggs and territory. Here, males do not suffer
much mating cost and hence we see greater amount of paternal care.
Rather, protecting one’s eggs and territory well attracts other female fishes
to lay their eggs on that territory thereby providin g more opportunities for
males to mate.
The mating opportunity cost hypothesis also lets us assume that in a
society where more females than males exist, men have greater mating
opportunity and hence will show poor participation in child rearing.
However if a society has more males than females, mating opportunities
will be less and hence males may show greater involvement (Pedersen
1991 as cited in Buss 2011). Some of the other factors that predict amount
of paternal involvement apart from sex ratio in th e society are
attractiveness of a male as more attractive males have greater mating
opportunities, population density since crowded places provide more
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90 Thus, the paternity uncertainty hypothesis and mating opportunity cost
hypothesis provide a compelling explanation for less paternal and more
maternal involvement in child care.
5.1.2: Parent -offspring conflict :
As stated previously, children are primary means for parents to pass their
genes and keep their species surviving. However, as human babies are
born out of mating of a male and female, every child shares with each of
their parent only 50% of genetic relatedness. This difference of 50% is
what is responsible for the conflict between them. This geneti c difference
is also the reason behind difference between parents and children about
allocation of resources wherein children want more resources for
themselves than for their parents.
Daly and Wilson (1998, as cited in Buss 2011), explain this conflict w ith a
simple example. Lets assume you have a brother and a sister. You mother
comes home one day with three loafs of bread. Now, for her the idea
allocation would be to give one bread loaf to each one of you. As she
shares 50% of genetic related with each one of you, each one is an equal
opportunity for her genes to survive. However for you, your siblings share
only 50% of your genes while you are carrying 100% of your genes. More
food means more survival and reproduction capacity. That is why you
would wan t all the three bread loafs to come to you. This is where the
difference in interest and conflict will begin between you and your mother.
To put the above example in generalized terms, the parent offspring
conflict theory states that parents and children will experience
disagreement primary based on resource allocation. Even in case of a
single child, the child would want a larger share of family resources which
would mean parents cannot spent it on their other reproductive pursuits.
This conflict is expe cted to occur during all the life stages however it may
become pronounced during adolescence as the child now tries to establish
their independent identity and begin mating pursuits for which resources
are needed.
Trivers (1974) indeed predicts these figh ts to occur instead of considering
it just as a possibility. Accordingly human evolution has produced some
adaptations in children that help them manipulate parents whereas parents
have also developed some counter adaptations to deal with the same.
Accordi ng to Buss (2011), the theory predicts following hypothesis:
1. Parents would expect children to be weaned sooner than children
wish to.
2. Parents would expect children to value their siblings more than
children want to.
3. The fights between siblings and with parents will be punished by
parents whereas agreement will be rewarded by parents.
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91 Parenting And Social Behavior - I Mother offspring conflict in utero :
As stated earlier, a mother is always 100% sure that the child belongs to
her. Mothers are also found to be more heavily involv ed in parenting than
fathers. As such it is surprising to know that evolutionary psychology
predicts conflicts to take place even between mother and children.
This conflict begins from conception. The same logic of parent offspring
conflict applies to mot her fetus conflict. It will be more beneficial for a
mother to invest in a child who is physically healthy enough to carry on
her genes than a weaker one. Therefore, women’s bodies have developed a
mechanism that produces spontaneous abortions in the firs t few weeks of
conception of the fetus has any genetic abnormalities. This saves mother
from investing her efforts on a child who will die early and thereby not
help in survival of her genes. It is found that 78% of eggs fail to fertilize
or get naturally aborted in the first few weeks of pregnancy (Nesse and
Williams, 1994; as cited in Buss 2011).
On the other hand, fetus has also developed some mechanisms to ensure
its survival. Pregnant women often experience high blood pressure. Fetus
receives nutritio n via mothers blood. When this nutrition is low, fetus
releases certain substances in mothers blood that make her arteries
constrict and result in greater blood flow and thereby greater amount of
nutrition to the fetus. Thus, the fetus clings to its life e ven at the cost of
mother’s health. This hypothesis is supported by the finding that women
who experience high blood pressure during pregnancy have fewer rates of
spontaneous abortions (Haig 1993; as cited in Buss 2011). Thus, this
explanation is an extens ion of Triver’s parent offspring conflict theory as
here the fetus is trying to grab more of a mother’s resources than her body
is prepared to offer.
Mother Child conflict and sibling related :
Following from the above discussion, another reason for pare nt offspring
conflict is presence of a sibling. While all the children are of equal value
to mother, every child would be against the equal distribution of her
resources and want majority of resources for themselves. In addition,
presence of a step sibling is even more conflicting than presence of a real
sibling as step siblings share only 25% of genetic relatedness.
Schlomer and colleagues (2010; as cited in Buss 2011) studied mother
child relationship with the help of a 20 item questionnaire. The study
found highest amount of mother child conflict in the presence of a younger
step sibling, followed by younger full sibling and least with np sibling at
all.
Parent offspring conflict over mating :
Mating is an important life event among human species. We hav e heard
several stories of children choosing a partner against parent’s wish. As an
offspring finding a mating partner and consequently producing children
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92 genetic relatedness with their grandparents. Selection of certain mating
partners over others benefits not only the offspring but their parents as
well. This is where the conflict enters. A person might be favorable mate
for an offspring but not to their parents. For example, a son migh t select a
female to be his partner who is physically healthy and thereby has capacity
to produce healthy children for him. However son’s father might want him
to marry another girl who is higher in socio economic status, thereby
providing an opportunity f or father to move up the social ladder and
increase his chances of reproduction and survival. Sometimes, offspring
might only be interested in a short term mating however if parents are to
spend their resources on offspring and their partner, it will be a costly deal
for them. Consistent with this, studies have found off springs to prefer
beauty when selecting mating partner whereas parents prioritize family
background. This gives rise to parents trying to control their daughters
behaviors and clothing, fo r example, in order to protect her from selecting
wrong (according to parents) mating partner.These restrictions are stricter
for daughters than for sons as females bear greater cost from wrong
mating choices than males. They are heavily involved in child rearing and
have lessor opportunities to produce a child than a male does. As such
finding a good long term mate is more crucial for them.
Consequently, children also try to influence mating and re mating decision
of their parents. Parental re mating mea ns possibility of step siblings who
prove to be strong competitors for parental resources. Therefore often
children resist parental divorce as well.
5.2 KINSHIP INTRODUCTION Several behaviors help humans accomplish task of survival. Mating, child
raring and kinship are some of them. Birthing and taking care of one’s
child helps them pass on their genes as there is 50% of genetic relatedness
between parents and children. We also share 25% of genetic relatedness
with our grandparents, cousins, uncles, aunt s, nieces, etc. Protecting and
helping one’s relatives is another way of passing genes and ensuring
survival of species.
Like children, relatives are also vehicles of survival. However they differ
in their value based on genetic relatedness. Selection has favoured
adaptations that help in kinship behaviors. However the preference will
always be given to one’s own self followed by relatives in their degree of
genetic relatedness. Selection has favored adaptations that promote
helping close kin more than dis tant kin and help distant kin more than
strangers. The characteristic of altruism has its origin in the principle of
inclusive fitness.
5.2.1 Theory of implicit and inclusive fitness :
The famous quote by Darwin states well accepted truth of evolution,
which is survival of fittest. The inclusive fitness is calculated by taking
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93 Parenting And Social Behavior - I relatives as well, differing in weight based on their degree of relatedness.
Let us understand this better with Hamilton’s rule.
Hamilton’s rule :
The acts of altruism are evolutionary riddle. Altruism is generally defied
as acts that involve some self sacrifice that leads to benefit of another.
Selection requires one to protect oneself and pass on one’s own genes for
the species to survive. As such altruism seems to contradict selection.
Hamilton has helped solve this riddle by arguing that altruism will not
prove to be costly if benefits of helping another person outweigh sacrifice
to one’s own self. In such case s it will rather prove to be an adaptation
rather than problem behavior. Further, helping another will be beneficial if
the other person shares some genetic relatedness with the on helping.
Closer the relatedness, more the benefit and stronger the tendency to help.
This rule can be expressed in formula as:
cHere, c is the cost to the one helping, r is genetic relatedness between
helper and the one getting helped, and b is the benefit to the one receiving
help. Here, both cost and benefit is defined in terms of reproductive
success.
To put it in an example, if you were to save your relatives from fire at the
risk of your life, doing so would be beneficial for you only if you are
saving, lets say , three young siblings than only one sibling or your
grand father (who has low reproductive capacity). Thus, Hamilton’s rule
specifies under which condition altruism can be expected to occur.
Relatives with stronger relatedness will always be preferred over
strangers. Humans have evolved with adaptations - behavio rs, reasoning
tendency, personality traits and emotions that favour confirmation to this
rule. Similarly, any behavior or trait that goes against this rule will be
rejected by selection. This phenomenon is known as evolvability
constraints where only the t raits that confirm to Hamilton’s rule are
evolved and passed on to generations whereas traits going against this rule
get terminated.
Theoretical implications of Hamilton’s Rule :
Following from Hamilton’s theory, humans have evolved with different
adaptat ions, mostly psychological for different relatives. Parent child is
one type of relationship that is influenced by this rule. Let us see how
other relationships are designed following Hamilton’s rule.
Siblings:
Sibling relationships are more complicated than a simple equation.
Siblings can help and protect each other the best as they share 50% of
genetic relatedness. At the same time they are also the strongest
competitor for parental resources. This is where sibling rivalry originates
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94 Sulloway (19 96; as cited in Buss 2011) has suggested differential behavior
of siblings based in their birth order. Parental behavior also changes as per
the number of children they have which in turn shapes children’s behavior.
According to Sulloway, first born get mo re of parent’s attention and
efforts hence they turn out to be more confirming to the parental rules
whereas second born gain better by revolting against instead of confirming
to the rules. Youngest siblings however often get better parental resources
than middle kids as parents often spend all their remaining investments on
the younger one, since youngest child is their last reproductive vehicle.
Several researchers have found empirical support for this prediction.
Siblings vs half siblings :
While full s iblings share 50% of genetic relatedness with each other, half
siblings only share 25% of genetic relatedness. According to Hamilton’s
rule then, one should be less likely to be altruistic towards half siblings
than with full siblings. Two children born to same woman but having
different fathers are very much likely to compete with each other for her
attention and care.
Grandparents :
Grandparents are share 25% of genetic relatedness with their
grandchildren. Evolution has allowed grandparents to develop c ertain
mechanisms that aid helping raising grandchild instead of one’s own child.
Menopause is the best example of this. The ‘grandmother hypothesis’
states that older women experience menopause as it stops their
reproductive endeavour, allowing them to he lp their children in raising
their kids instead.
Some universal aspects of kinship :
Daly, Salmon and Wilson (1997; as cited in Buss 2011), have made
predictions about certain universal aspects of kinship, based on
adaptations resulting from inclusive fi tness. They suggest an ego centered
kin terminology such as ‘my parents’, ‘my brother’, ‘my niece’ etc. Which
distinguishes between people that you are connected to genetically and
those who are unrelated. Further, they predict that kinship will be
disting uished along sex. For example, mothers will be distinguished from
fathers, uncles from aunts, brothers from sisters, etc. This is salient as sex
implies genetic conformity. Females are always 100% related to the kinds
but same cannot be said about the fath er. Sons have more reproductive
opportunities than daughters. Next, the kin will also make distinctions
along generation as older generation becomes less and less reproductive
wise useful as younger generation becomes more and more useful. The
researchers also predict that emotional closeness will mirror genetic
closeness. Sixth prediction suggests that elders of the family will always
encourage younger ones to be altruistic and cooperative with each other
more their natural preference. Seventh prediction c oming from
inclusiveness fitness theory asserts that one’s position in family will be a
central aspect of one’s self concept. Even today, people often identify
themselves as ‘I am daughter of_’, ‘ Father of_’ , etc. Eighth formulation munotes.in

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95 Parenting And Social Behavior - I suggests that humans across cultures will be aware of different degrees of
genetic closeness with relatives, even though their language may or may
not make this distinction. Finally, considering the benefits enjoyed as a
result of inclusive fitness, kinship terms will be used for persuasion and
influencing strangers. For example, one may say ‘ Hey brother, can you
help me with this address?”. This is because hearing the term ‘Brother’
activates kinship preference which might make even a to stranger help
you.
5.2.2 Empirical su pport for theory of implicit and inclusive fitness :
Several of studies support claims made by the theory of inclusive fitness.
These studies include observations of humans, primates and some other
animals that we share great deal of genetic makeup with.
Mechanisms for kin recognition :
Hamilton’s principle expects humans to help their genetic relatives which
further adds to their inclusive fitness. In order to help a kin , one first
needs to recognize who are one’s genetic relatives and to what degree .
One way in which humans recognize their close relatives with the help of
smell. Newborns often distinguish between their mother and other humans
with the help of her smell (Cernoch and Porter, 1985; as cited in Buss
2011). We can often identify which fam ily member wore a particular shirt
yesterday by smelling it. There is also evidence of adolescents recognizing
their full siblings by smell but not their half siblings.
Humans use the adaptive technique of using specific linguistic terms such
as uncle, au nt, mother etc, to distinguish relatives from strangers and from
one another. Further, infants are often exposed to these close relatives so
that they learn to recognize their kin from early in life. Terminologies also
help in classification of relatives. There are cultural differences in these
terms. For example, Marathi language has different terms for mother’s
brother (mama) and father’s brother (kaka) whereas English language uses
same word to indicate the both (uncle). According to researcher Doug
Jones (2003a, 2003b; as cited in Buss 2011), there is a universal grammar
that governs kin terminology that consists of three systems: genealogical
distance, social rank and group membership. Genealogical distance is
degree of genetic relatedness. The genealog ical distance between siblings
is different from that between an uncle and niece. Elders in the group are
usually given higher social rank than younger ones. Membership is
determined based on groups such as maternal vs paternal relatives, same
sex vs diff erent sex relatives, etc.
Interestingly, physical similarity also helps one identify a close kin.
Individuals who are genetically closer to each other often share a lot of
facial features, posture, voice texture, etc. Further, humans also tend to
distrust a face that looks extremely dissimilar to oneself. Humans can also
detect who are related to each other in a group of strangers as well. This
serves the adaptive value of knowing who will ally with whom if the
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96 Thus, humans have four ways of identifying kin: through association,
odor, linguistic terminologies and physical resemblance.
Altruism among humans:
A Study by Burstein, crandall & Kitayama, 1994, tested two types of
altruistic be havior extended to people of different genetic relatedness to
participants. Two types of behaviors were significant helping behaviors,
such as helping in case of life and death matters and trial helps such as
giving food or some money to someone. They want ed to see if participants
were more likely to help their closer relatives than strangers, also if more
help is provided to younger ones (as they carry more reproductive
potential) than older relative. Participants from US and Japan were
presented with some scenarios such as being able to help only one person
from a burning building vs picking up a couturier for someone. Results
showed that helping in such scenarios increased with increasing degree of
genetic relatedness, especially in case of life and death scenarios. Helping
in such cases also decreased as victim’s age increased. 70 years old were
much much less likely to be helped than a 10 year old.
In another interesting study by Stewert -Williams (2008; as cited in Buss
2011), participants reported feel ing emotionally closer to their mates and
friends than to their siblings; however when cost of helping increased,
they were found to be helping siblings more and more than friends and
mates. Studies from several non industrial cultures have also found
evidence for food sharing happening more among kin households than
others in the village.
Kin relationship seems to be more valuable to women than men.
Patriarchal societies require a woman to shift with husband’s family after
wedding. However across several cultures women are found to maintain
contact with their kin after marriage as well. They often stay with kin
when pregnant, after divorce or death of spouse (Buss, 2011).
Genetic relatedness and emotional closeness :
Selection has also lead to developmen t of some psychological mechanism
that help humans in survival and reproduction, as well as to maintain their
inclusive fitness. Emotional closeness is hypothesized to be one such
mechanism. Korchmaros and Kenny 2001(as cited in Buss, 2011),
extended Burne stein’s study by asking participants to rate emotional
closeness to different genetic relatives on a 7 point likert scale. Then they
were presented with hypothetical situations involving an opportunity to
show altruism. Results showed that not only genetic relatedness but
emotional closeness also predicted tendency to help; further, individuals
were found to be feeling more emotional closeness to kin who are
genetically closer than those who are genetically distant. Humans also
tend to have more frequent co ntact with their genetically closer relatives
which in turn increases their tendency to help them (Kurland and Gaulin,
2005).
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97 Parenting And Social Behavior - I Vigilance over Kin’s Romantic Relationships :
As it is followed from inclusive fitness, mating success of not only oneself
but on e’s relatives especially sibling is also important for evolutionary
tasks. Therefore it is expected that humans will be quite vigilant regarding
good and bad qualities of mates of their siblings, especially mate of their
female siblings as females carry mo re value with respect to passing genes
than males (Faulkner and Schaller, 2007 ; as cited in Buss 2011).
Kinship and stress :
Several researchers have noted relationship between stress and presence/
absence of kin. Cortisol is a chemical secreted during s tress than prepares
body to fight the stress. However the flip side of excessive secretion of
cortisol is its adverse effect on reproductive and general health of the
human. Studies have found that children living with single parent,
especially mother show higher levels of cortisol in blood than those living
with both the parents. But, if a kin stays nearby a child raised by single
parent, the levels were found to be lower. Similarly, children living with
step parents or step siblings showed highest stress levels (Flinn et al, 2005;
as cited in Buss 2011). This is because presence of a genetically related
kin provides better protection to a child than living with those unrelated.
Grandparents and grandchildren :
As females are always 100% sure that the chi ld is theirs, when it comes to
grandparents, a mother’s mother is hypothesized to invest most in children
of her daughter than any other grandparent. A maternal grandmother is
100% sure that her daughter is her own and the daughter in turn is sure
that her kinds are her own. Taking care of daughter’s children is always
beneficial for maternal grandmother. Other grand parents, that is , father’s
mother and father and mother’s father have some chance of either their
child or grandchild not being genetically r elated to them. A study
conducted by DeKay(1995; as cited in Buss 2011), asked participants to
rate all four of their grandparents on measures of physical similarity,
resourcefulness, time and knowledge. The findings supported the
hypothesis regarding mate rnal grandmother.
5.3 SUMMARY Survival and reproduction are two most important evolutionary tasks of all
the humans. Accordingly, they have developed some physical and
psychological mechanisms that help them ensure successful completion of
these tasks. C hildren are primary way of passing on one’s genes and
keeping one’s species alive hence taking care of children becomes at most
importance. Mothers and fathers differ in their investment in child. This is
because since female is responsible for gestation a nd delivering the baby,
she is always 100% sure that the baby is her; however for the father there
is always a chance that baby was conceived with another male. Therefore,
fathers across cultures are found to be less involved in child rearing than
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98 likely to advocate equal distribution of their resources among children.
However as a person shares only 50% genetic relatedness with their
sibling, every child is likely to want more paren tal resources for
themselves and less for their siblings. This leads to parent offspring
conflict.
The principle of inclusive fitness states that a person’s reproductive
success can be calculated not only by adding their direct reproduction -
their children , but also reproductive success of their kin. Hamilton’s
theory further explains humans engage in altruistic acts when helping
another person is more beneficial than keeping resources to oneself. This
usually happens when other person is genetically close and has better
reproductive potential. Therefore people are more likely to help their
close relatives followed by distant relatives and least to strangers.
Hamilton’s rule is represented in the formula: cHumans have also developed mechanisms such as physical resemblance,
emotional closeness, odor recognition, terminologies, frequent contact etc.
to identify close kin and help them. Abundance of empirical evidence
supports principle of inclusive fitness and Hamilton’s rule
5.4 QUESTIONS 1. Explain reasons behind differential parental investment in their
children
2. Describe parent offspring conflict
3. What is the theory of inclusive fitness?
4. Explain the principle of inclusive fitness with the help of its empirical
correlates.
5.5 REFERENCES  Buss, D. (2011). Evolutionary Psychology: A new Science of Mind.
Pearson Education.
 Barkow, J. H., Cosmides, L., Tooby, J. (1992). The adapted mind.
Oxford University Press.

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99 6
PARENTING AND SOCIAL BEHAVIOR - II
Unit Structure
6.0 Objectives
6.1 Group living for humans
6.2 Evolution of cooperation
6.2.1 Reciprocal altruism
6.2.2 Cooperation among non -humans
6.3 Cognitive adaptations for social exchange
6.4 Summary
6.5 Questions
6.6 References
6.0 OBJECTIVES After studying this chapter, the students will be able to:
• Understand the concept of cooperation and how it evolved in humans
• Understand what is reciprocal altruism
• Understand how human brain has adapted to do various forms of
social exchange
6.1 GROUP LIVING FOR HUMANS Humans, unlike most of the other animals, do not have bodily weapons
such as sharp nails, ability to run fast, wings to fly or sharp teeth to protect
themselves in dangerous situation. O ne way for them to protect
themselves from a predator is by living with other humans, in the form of
a group. Now, if a group is to function well and provide protection to its
members, cooperation is a must trait. As such, humans have made several
psycholo gical adaptations that ensure smooth functioning of the group.
This also means that humans have mindset that allows for solving
problems of group living. Cooperation, aggression, conflicts are some of
these problems. In this chapter we will study the probl em of cooperation
in detail with the help of theories such as reciprocal altruism, costs and
benefits of friendships, commonly seen examples of altruism in nature and
explanation of adaptations made by human mind to make this all possible.
6.2 EVOLUTION O F COOPERATION Friendship is one of the oldest forms of cooperation. Defined in simple
words, cooperation is an act of working towards a same goal. It is a form
of social exchange. Cooperation is what makes a family or a big
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100 and across different species as well. The personality trait of agreeableness
is an asset for cooperation wherein people who are high on agreeableness
usually cooperate well and prove to be a good team member.
Howe ver, selection process prizes survival of the fittest. As such
understanding why one would help another survive at one’s own cost is an
evolutionary puzzle. In last chapter we understood that one may engage in
altruism when survival benefits of saving a ge netic relative are greater
than cost of loosing one’s own life. We also understood that people are
more likely to help others closer in genetic relatedness and younger in age.
But a friend is not genetic relative and is often of similar age as oneself.
Why would one help such a person who may very well be a competition to
win over a healthy mate? This is also known as the problem of altruism.
The theory of reciprocal altruism answers this question.
6.2.1 Reciprocal altruism:
In simple words, the theory of reciprocal altruism says that a human may
help non relative in situations where there is a possibility of the help being
reciprocated in future. This way, the one who is helping and the one who
is being helped, both benefit. Lets take an example of huntin g. Getting a
good game is not a frequent event. One day you may get enough meat for
your family, other days you may walk miles without any hunting success.
One way to solve this issue is becoming friends with another hunter. That
way you both can help each other. If, for example, today you get a big
game, you may share it with your friend. Tomorrow if you do not score
any thing but your friend does, he will share is food with you. Moreover,
you will also be more powerful if you hunt together than alone. Thu s, you
both benefit out of this deal. It is a win win situation.
Speaking in evolutionary terms, humans who developed this trait of
reciprocal altruism will be more successful reproductively and thus
outnumber those who are selfish. Reciprocal altruism ca n then be
conceptualized as ‘cooperation between two or more individuals for
mutual benefit’ (Tooby and Cosmides, 1992; as cited in Buss, 2011).
Thereby the terms cooperation, reciprocation, social exchange mean the
same.
The phenomenon of reciprocal alt ruism also calls attention to the problem
of cheating where one may only enjoy the benefits without returning the
favors. Interestingly, humans have also evolved psychological
mechanisms to detect cheating. We will discuss those adaptations a little
later in this chapter. Let us now study an interesting phenomenon that
throws light on important aspects of cooperation, something known as the
prisoner’s dilemma.
Prisoner’s dilemma:
The workings of cooperation can best be illustrated by a hypothetical
situati on called as prisoner’s dilemma. In this situation two people are
accused of committing a crime that they have indeed committed. Both are
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101 Parenting And Social Behavior - II and are inquired separately by police. If none of them confess, there will
be no proof of their crime and both will be set free. However if one of
them rats out against the other then this person will be rewarded and the
other one will get even stricter punishment. If both of them confess, they
will be sentenced to jail.
This situation presents a dilemma as although the rational action is to
confess, it will lead to punishment for both than if they trust each other
and do not confess. Here, term R is used for reward of setting free, P is the
punishment each receives of both confess, T is temptation to confess
against the other prisoner and S is sucker’s pay off which is punishment
one gets of the partner rats out and one does not.
Lets examine this dilemma from player A’s point of view. He will benefit
if he defects but his partner does not. But if his partner defects, he will be
better off defecting as well. Thus, defecting appears more appropriate than
mutual cooperation although that option is mutually rewarding. In real
life as well, both the part ies benefit with mutual cooperation but there is
always the temptation to benefit even more by defecting against another
while they do not.
After a lot of research, the winning strategy for this game is discovered to
be Tit for Tat when the fame is played multiple times. It is effective if first
move is to cooperate and then reciprocate whatever move the other one
does. This is also called as ‘contingent reciprocity’ as one’s cooperating
behavior depends on behavior of another (Trivers 1985; as cited in B uss
2011).
6.2.2 Cooperation among non humans:
Cooperation is an adaptive behavior not only for humans but for majority
of species on earth. Let us examine some examples.
Vampire bats:
These bats consume other animal’s blood. They usually venture out to
suck blood during night and hide in caves during day. Their groups consist
of female bats and their off springs with male bats going out to collect
blood when they get old enough. Interestingly, they can live without blood
only for three days. Blood sucki ng, like hunting is unpredictable. Then
how do they deal with this problem?
Bats seem to be using reciprocal altruism. Studies have found them donate
collected surplus blood to their friends who have helped them in past. This
tendency to give blood to frie nd bat also increases when friend is close to
dying than when their need is mild. Starved bats were also more likely to
return the help. Thus, vampire bats have developed mechanism for
reciprocal altruism for survival.
Chimpanzees:
An observational study by de Waal (1982; as cited in Buss 2011) studied
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102 as human world. In this study they observed behavior of an alpha male A
who dominated the group with his physical strength and showed sexual
prowess by mating with majority of the female of the group. With time he
grew old and a young chimpanzee B gained more power. He soon
dethroned chimpanzee A with physical fight and left him with 0 mating
partners. However chimpanzee A formed an alli ance with an newer
younger chimpanzee C and together they fought against chimpanzee B.
They of course won this fight and C, being the younger one secured 50%
of mates whereas A gained 25% of mates which is much better than 0
mates when he was dethroned.
Thus, cooperation helps chimpanzees to sustain power and survival in the
group.
6.3 COGNITIVE ADAPTATIONS FOR SOCIAL EXCHANGE As cooperation and altruism is a form of social exchange, humans have
developed several adaptive mechanisms that ensure behaviors consistent
with it.
Social contract theory:
Theory of reciprocal altruism states that people help others so that they get
help in return. However acts of reciprocal help do not occur at the same
time, always. If I fail at hunting today and you help me by sharing food
that you have hunted, I cannot return this favor immediately by giving you
food. This creates the possibility of cheating. Cheating is the biggest threat
to cooperation.
Cosmides and Tooby have developed theory of social contract to explain
social exchange in such situations. They propose that humans have
evolved mechanisms to detect and avoid cheaters. With this, cheaters will
be at disadvantage as cooperators will align with other cooperators and
avoid them. They have proposed five such mec hanisms that humans have
developed:
1) Ability to recognize different individuals:
First of all, to return the favor you gave me, I should be able to distinguish
you from other humans so that in future when you are in need I can come
forward to help. Sec ond, if I get deceived by someone once, I can avoid
them next time only if I recognize them. Therefore humans have
developed ability to recognize difference in humans to distinguish
between them effectively and form alliance accordingly. We are so good
at it that it almost seems to be an obvious behavior instead of a specific
ability. Alternatively, lesion to brain area involved in face recognition
leads to a condition called ‘Prosopagnosia’ which is inability to recognize
faces.
2) Humans also have memor y of interactions with others. This memory
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103 Parenting And Social Behavior - II the past when it comes to helping them right now. This helps them
decide if the other one was cooperator or cheater. It also helps them
remember who owes whom so that know false claims can be made by
those who owe help to the other person. If you fail at this ability, you
may end up giving much more benefits than what you receive.
3) In order to clearly convey to the other what I need in return of t he
favor I did, I should be able to communicate my needs to them. This
is third capacity that humans have developed to facilitate reciprocal
altruism. Similarly, if I don’t express my anger and disappointment
when being cheated on I will be perceived as a weak member of
group and become more prone to being cheated again.
4) In line with previous ability, along with ability to communicate one’s
own value to others, we also have the ability to understand other’s
value. Recognizing when one is in need and ho w much and what kind
of help they need can help alter help we provide accordingly. Giving
someone a rug to cover themselves when what they need I actually
food, help provided will be worthless. Recognizing other’s value and
need can help the helper maximiz e value of their help.
5) Last but one of the most useful ability is to compute cost and benefit
independent of the specific items exchanged or help provided. There
are innumerable number of things that humans can exchange - food,
cloths, tools, shelter, status, protection, etc. One needs to compute
worth of each of these items and compare them. Giving someone
shelter in exchange of a pen will be a costly deal. The ability to
conceptualize cost and benefits in general terms than specific items
helps overco me this problem.
Thus, social exchange theory proposes five abilities that humans have
evolved that ensure cooperation and deal with problem of cheating. By
being able to recognize different humans, remembering interactions with
them, communicate and unde rstand one’s own and other’s value and
compute cost and benefit irrespective of the specific item exchanged helps
to do that.
Cheater detection adaptations - logical problem solving:
How humans solve logical problems gives a glimpse of adaptations mad e
in accordance to social contract theory. Logical problems are often
presented in form of If “p then q”. For example, if it rains, the roads will
be wet. This is then followed by a problem statement such as ‘p’; ‘roads
are wet’. The respondent has to arri ve at the logical inference from given
information. The correct answer is “q” ; ’then the roads will be wet’. Thus,
when situations state if p then q , whenever p is true logically q is also
true.
Studied have shown that humans are not so good with drawin g such
logical inference. A study by Pinker et al., 1997 (as cited in Buss, 2011)
presented college students with premise that in a room there are some
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104 biologists are archaeologists but al l the biologists are chess players. More
than 50% students concluded from this information that none of the
archaeologists are chess players. Which is an incorrect conclusion. It is
also possible that some archaeologists are ALSO chess players. The
informa tion says all biologists are chess players. It does not say only and
only biologists are chess players to conclude that archaeologists are not
chess players.
Wason card problem is another famous logical problem solving situation
that sheds light on human problem solving skills. It presents respondents
with 4 cards, two of them have a letter written on them - A and K and
other two have number written on them - 2 and 7. The task is to check
only two cards to see if the rule ‘If a card has vowel on one side, it will
have an even number on the other side’. Majority of the people select card
A and 2. Now, while selecting card A is correct choice as it has to have an
even number on the other side failing to which the rule is proved false,
turning card 2 is not us eful here. Again, like in previous paragraph, the
rule says if a card has vowel on one side it will have even number on the
other. It does not say only and only the cards with vowel on one side have
even number on the other. Which means even cards with con sonants may
have an even number on the other side. Therefore any letter could be
behind card 2 which will not prove anything about the rule. The correct
answer is card 7. If card 7 has a vowel on the other side then the rule is
falsified.
To put this in ab stract terms, given “if p then q’, concluding ‘p therefore q’
and ‘not q not p’ are the only logically correct inferences. Rest two
possibilities = ‘q therefore p’ and ‘not p not q’ are logically incorrect
conclusions. Studies show that humans are good at concluding if p then q,
but make logical fallacies when it comes to other conclusions.
Evolutionary psychologists explain this finding by stating that humans are
not evolved to solve abstract problems. Solving abstract problems did not
serve any purpose t o our hunter gatherer ancestors. However solving
social problems was indeed useful to them. Consider this example, you
have to verify the rule that “If a person drinks alcohol they must be twenty
one years or older”(Cosmides and Tooby, 1992; as cited in Bu ss 2011).
There are four people sitting at the table: a sixteen year old, a 25 year old,
someone sipping wine and someone sipping juice. Which two people
would you approach two check if the rule is being followed? Majority of
the people correctly pick some one sipping wine and sixteen years old.
Interestingly, this answer follows same logic as above abstract problem. If
p (drinks alcohol) then q (must be 21 or above). Concluding p therefore q
(sipping wine therefore has to be 21 or older) and ‘not q not p’ ( sixteen
years old therefore shouldn’t be drinking alcohol) is logically correct
answer.
Thus, evolutionary psychologists showed how humans are better at
solving social problems than abstract problems because solving social
problems, specifically detecting cheaters provided them an evolutionary
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105 Parenting And Social Behavior - II the same. People are much much more efficient when it comes to solving
problems presented in the form of a social contract. The context
familiari ty is not the key here as people solve such problems even when
presented with weird rule such as ‘only those with swollen arm will get
entry in mall’. Human mind is evolved to detect cheaters no matter what
the rule is. This is a cross cultural evidence.
Further, different brain areas are devoted to such adaptations. In a famous
study of a patient with brain damage to amygdala and some areas of
frontal cortex, it was found that the person was still good with
precautionary problem like “ always wear mittens when holding hot pan’
but his ability to solve social contract problems such as mentioned above
was deteriorated. Such people are more likely to get deceived by others.
Cheater detection adaptations – memory:
Remembering who has cheated in past provid es an evolutionary advantage
as one will not associate with that person again. Some studies have rather
found that people are better at remembering faces of cheaters better than
remembering faces of cooperators from past. This could also be because
cheater s are usually fewer than cooperators as majority of the humans are
evolved to cooperate than to cheat. Some studies also claim that cheaters
give away some subtle cues through their facial features and expressions
that give a hint to respondent as to wheth er they are cheaters or not and
thereby also help them to remember such faces better even without actual
knowledge about whether the person is cheater or not. For example, while
smiling indicates a potential cooperator, expressions of contempt indicate
a potential cheater. People are even better at making these judgments if
they have been primed by asking them to remember an occasion when
they were cheated, before they are asked to make these judgments.
Thus, humans have evolved memory as well as attention al capacities that
aid in cheater detection.
Cheater detection adaptations - detection of altruists:
Interestingly as humans have evolved mechanisms to detect cheating,
cheaters have also evolved mechanisms to avoid getting detected. In turn,
humans have also developed tactics to detect altruists, moreover genuine
motives behind altruism.
Evolutionary psychologists have conducted studied similar to Wason card
problem but tweaked to detecting genuineness. The rule states “ if X helps,
she gets the point”. The four cards are “X helps” , “X does not help”, “X
takes point”, “X does not take point”. The cards of “X helps” and “X does
not take point” shows genuine altruism. Majority of the respondent
correctly select this. This performance was equally good as p erformance
on cheater detection task and both were still better than solving abstract
problems.
Surprisingly, people have shown ability to detect genuineness in others
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106 Altruists are h ypothesized to display a more genuine smile than non
altruists.
Thus, detection of cheaters and detection of altruists are two broad
adaptations that humans have developed that facilitates reciprocal
altruism.
Added benefit for altruists - costly signalin g theory:
Altruists definitely enjoy the direct benefit of getting another person’s help
after helping them. However they also enjoy an added benefit they get by
advertising their altruist acts. When one popularizes their altruist acts or
others talk abou t X person’s altruism. He/she appears more attractive and
trustful for others. Others may then try to form alliance with X individual
in future. The benefit is then not limited to receiving help form the person
you helped, nut also from others who have hea rd about your altruism.
This is why people are often more helpful when others are watching. This
also explains why popular personas often post their generosity on social
media, in order to influence their followers.
The theory of costly signaling or cost ly helping is related to this. Only
those who have extra resources can afford to help others. By displaying
their altruism, throwing dinner parties, giving expensive gifts, charity,
donations etc. one is also informing others subtly that they have more tha n
enough resources available. This is an attractive quality when it comes to
mating as well as forming alliances and maintaining groups. Those who
sacrifice themselves for others often get more respect by the group and
receive help when needed. Such people also have higher status in the
group. Studies have found that people often tend to help more when doing
it publicly than when doing it anonymously.
Banker’s paradox:
Banker’s paradox throws light on an unexplored aspect of altruism.
Usually the number of people asking for loan are more than the amount of
money a particular bank has. Therefore a banker needs to decide whose
loan should be approved and whose not. People having good salary, for
example, are safer risk than someone with low salary. However those in
need of money are precisely the people who lack money or steady income
source. They are the ones in need. Should they then be helped or not?
To apply this paradox to social exchange, often people in need are the
ones who have poorest resources; t hat is why they are in need. A person
struggling with cancer would need your help. However he cannot provide
any benefits to you immediately or in near future. What should you do in
such cases where reciprocity of altruistic act is a thin possibility?
Evolutionary psychologists argue that this dilemma is resolved by
considering A. character of the person. Whether the person is known to be
a cooperator or cheater. B. How likely they are to help you in future. And
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107 Parenting And Social Behavior - II these questions ensure that one’s investment in others will not go loss. By
this rule, those who are in temporary need are more attractive recipients of
help than those whose problem is likely to be persisting.
As a recipient of help, one way to ensure you get help when needed is to
become ‘irreplaceable’. Tooby and Cosmides (1996; as cited in Buss
2011) have highlighted some of the ways to become irreplaceable. Some
of those are maintaining a reputation that highlights one’s qual ities,
identifying priced values that are difficult to achieve and trying to achieve
them, learn skills, hang out with groups that value your qualities and avoid
groups that do not need your attributes, trying to do away anyone offering
same qualities as y ou do.
Forming friendships is one way to ensure you get help when needed.
Evolutionary psychologists have suggested some ways to ensure this such
as being with friends who find you irreplaceable, who want same things as
you, being with friends who underst and your needs, etc. The ability to
distinguish between fair weather friends and real friends is extremely
adaptive.
Friends also provide a lot of other evolutionary benefits apart from
providing help. They often share their food and shelter with us, may
provide protection, introduce us to potential mates or even be those mates.
Cost and benefits of having friends differ by several dimensions such as
gender. While a same sex friendship carries potential of intra sex rivalry,
opposite sex friendship offers the advantage of potential mating. For men,
opposite sex friendship offers possibility of short term. While for women a
benefit of opposite sex friendship is protection. Opposite sex friends also
provide one information about their own gender which further helps them
get mates.
Apart from friendships, humans also form cooperative coalitions. These
coalitions offer benefits such as sharing food, hunting together, attacking
the other group together, etc. These coalitions also have to deal with
problems of de fection and free riders. Defectors are group members that
withdraw in the face of difficulty and free riders are members that share
group benefit without providing anything for group’s success. The strategy
of punishment is often used to deal with this pro blem. However, punishing
brings with it a potential cost. When A punishes B, A looses chance of
getting helped by B in future at the same time he incurs cost of potential
revenge from B. That is why punishing is also called as an altruistic act
that one pe rforms for the sake of their group. Such group members are
well respected in the group and enjoy a higher status. They are also
perceived to be more trustworthy and fair. This makes them attractive
member for forming alliances. This is the benefit they ob tain in return of
the cost of being the one punishing the defectors or free riders.
6.4 SUMMARY This chapter has shown us a true meaning behind the saying “man is a
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108 done to ensu re survival and reproduction of the species. Group living is an
ancient behavior and several psychological mechanisms are evolved to
facilitate that group living. Reciprocal altruism, cooperation, detection of
cheaters, detection of cooperators, etc are so me examples. It is interesting
to observe claims of evolutionary psychologists in this regard in modern
ways of living as well. In line with evolutionary hypothesis, we see even
today how people are more likely to help their close relatives than
strangers, help strangers when there is a possibility of getting reward for it,
pick on subtle cues of someone’s cooperativeness, advertise one’s
cooperative behavior, etc. The changing times however present different
problems and solution to those problems lies in modern time adaptations.
Human species will continue to survive on earth successfully if they
develop these adaptations.
Group living provides evolutionary advantage to humans as it helps them
protect themselves better from predators, gives better ma ting opportunities
and any other help when needed. For group living to happen smoothly
humans have to solve problems of group living. These problems are
solved by mechanisms such as altruism, cooperation, aggression, etc.
Cooperation and altruism are a for m of social exchange. Altruism is seems
contrary to selection theory as it involves helping another at one’s own
cost. This question is answered by the theory of reciprocal altruism. The
theory of reciprocal altruism states that humans help another when th ere is
a possibility of getting help in return from that person. For example, in a
hunter gatherer society, if one fails to obtain any game today, his neighbor
may help him by sharing some of the meat that he has obtained.
Tomorrow if the neighbour doesn’t have any food, you are likely to return
that favor. Thus, both the parties benefit. Prisoner’s dilemma is a
popular way to study cooperation strategies. In this game, participants are
presented with an imaginary situation where two people are bein g inquired
separately for crime they have committed. If both of them confess, they go
to jail, if one rats out the other, he gets reward while other gets a stricter
punishment, if both deny the crime, they are set free. This presents a
classic dilemma as i f one party doesn’t confess but other one does, they
get in more trouble; confessing seems better than that. After several trails,
researchers have found the best strategy to solve this problem, when
played multiple times is to cooperate first time and the n mirror partner’s
response. Cooperation is found among not only humans but also non
humans like vampire bats and chimpanzees.
Humans have evolved several cognitive adaptations that facilitate
reciprocal altruism. These adaptations involve ability to diff erentiate
between persons so as to know who is helpful and who is not, having
memory of the interactions with others, ability to communicate one’s
value to others and to understand other’s value, ability to calculate cost
benefit analysis that is not conne cted to the specific items exchanged.
Along with adaptations that facilitate reciprocal altruism, it is equally
important to detect cheaters. Studies have found that people are better at
solving logical problems when presented in terms of social exchange and
not in abstract terms. This is because it was always more adaptive for our munotes.in

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109 Parenting And Social Behavior - II ancestors to solve problems of social exchange than solve abstract
problems like “if p then q”. These findings are received from experiments
that use Wason card task. Further, h umans also have better memory to
remember faces of cheaters than faces of cooperators. They also seem to
be paying better attention to cheater’s subtle physical cues than
cooperators. This gives an evolutionary advantage to detect cheaters
easily. Studies have been conducted where participants are shown
pictures/ silent videos of strangers going about their regular tasks and still
people give accurate ratings about how cooperative the person in
picture/video is likely to be. It is hypothesized that cooperat or’s display a
more genuine smile than people low on cooperation. This helps us
estimate how cooperative the person is likely to be.
Altruism also gives another advantage when someone’s altruistic acts are
displayed. When others come to know about a perso n’s altruistic acts, that
person is perceived as more trustworthy and attractive. Others are more
likely to form an alliance with such a person. Friendships and cooperative
coalitions are some other forms of social exchange.
6.5 QUESTIONS 1. Write a no te on cooperation as a mode of social exchange
2. Explain principle of reciprocal altruism
3. Discuss cooperation among non human species with the help of
examples.
4. What cognitive adaptations have humans developed to facilitate
social exchange?
5. How do humans detect cheaters?
6.6 REFERENCES • Buss, D. (2011). Evolutionary Psychology: A new Science of Mind.
Pearson Education.
• Barkow, J. H., Cosmides, L., Tooby, J. (1992). The adapted mind.
Oxford University Press.

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110 7
SOCIAL BEHAVIOR AND SPECIFIC TOPICS - I
Unit Structure
7.0 Objectives
7.1 Introduction
7.2 Aggression as a solution to adaptive problems
7.2.1 Why are men more violently aggressive than women
7.3 Empirical evidence for distinct adaptive patterns of Aggression
7.3.1 Evidences for sex differnces in same sex aggression
7.3.2 Context triggering Men’s aggression against Men
7.3.3 Causal contexts Triggering Women’s aggression against
Women
7.3.4 Contexts Triggering men’s Aggression against women
7.3.5 Contexts Triggering Women’s Aggression against Men
7.4 Conflict between Sexes
7.5 Conflict about the timing and occurence of sex
7.5.1 Conflict over sexual access
7.6 Sexual Aggression
7.6.1 Sexual Harrasment
7.6.2 Sexual exploitation and cues to sexual exploitability
7.6.3 Sexual Aggressiveness
7.7 Jealous Conflict
7.7.1 Sex differences in Jealousy
7.8 Sex differences in the use of mate retention tactics
7.8.1 Context Influencing Mate retention Strategies
7.8.2 Destructive side of Mate rete ntion
7.9 Evolution of Morality
7.9.1 Free riders and social contract
7.9.2 Strong reciprocity and prosocial interest
7.9.3 Social embeddedness
7.10 Evolution of Art
7.11 Evolution of Emotion
7.11.1 Origin and functions of emotions
7.11.2 Appraisal theories of Emotions
7.11.3 Social Emotion
7.12 Summary
7.13 Questions
7.14 References
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111 Social Behavior and Specific Topics - I 7.0 OBJECTIVES After studying this unit you should be able to:
 Understand the adaptive problems critical to survival.
 Know the strategies adopted by human beings to deal with adaptive
problems.
 Understand aggression as a solution to adaptive challenges.
 Understand differences in pattern aggression as a function of sex.
 To study and analyze different type conflicts arises between sexes.
 Understand an evoluti onary basis of Morality and Art
 Acquire the knowledge about how emotions evolved.
7.1 INTRODUCTION We often say that a man is a social animal and cooperates with each other
to function in a society. However plenty of instances and empirical
evidence show t hat human beings sometimes go against the very nature of
a social being and choose to aggress against each other. We come across a
number of such news articles featuring such aggressive acts often in
media, news channel and television. Have we ever wondere d why human
beings engage in any sort of aggression? What function does aggression
serve? Are there any differences in the pattern of aggression as a function
of sex? What type of conflict typically occurs between men and women?
Can we trace back the aggre ssion and common conflicts to evolutionary
roots? Do we only engage in the activities critical to survival? Why do we
often spend time pursuing hobbies and art, which are not necessary to
survival? In this unit, We will try to look at all the questions fro m an
evolutionary perspective.
7.2 AGGRESSION AS A SOLUTION TO ADAPTIVE PROBLEMS Have you ever thought of using aggression as a strategy to overcome any
of the problems? If so, Is aggression a new age phenomenon or can it be
traced back to the time of evol ution? Empirical evidence suggests that our
ancestors gained multiple benefits by using aggression as a tactic and by
inflicting harm on rivals. In this unit we would make an attempt to
understand how aggression is used as a solution to solve adaptive
problems and also will shed a light on sex differences in aggression. Now
we would look at some of the leading candidates of adaptive problems for
which aggression might be used as an adaptive solution (Buss & Duntley,
2008; Buss & Shackelford, 1997b).
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112 1) Co -opting resources of others:
Human beings show a tendency to maintain a reserve of all the goods
critical for survival and reproduction such as Fresh water, access to land,
tools, food and weapons. There are plenty of ways to acquire these
resources such a s social exchange, stealing and Aggression. On an
individual level, one can secure valuable resources simply by using
physical force whereas on group level people can form alliances to
forcibly acquire resources from others. Co -opting resources as a strate gy is
used across all the ages. In childhood, aggression is often seen over toys
and territory (Campbell, 1993). In adulthood, aggression could be used as
a means to secure money or other goods by beating others. The perpetrator
creates a threat of aggress ion in the minds of the potential victim. This
threat or fear might be enough for the potential victim to give up the
resources in order to protect or prevent the danger.
2) Defend against attack:
The potential victims of aggression often stand at high ris k of losing their
valuable resources, status and reputation. In extreme cases victims might
also suffer serious physical injuries or death, placing the survival and
reproduction at stake. Defending against the attack is therefore used as a
means to prevent the harm or loss of face and honor. According to Buss,
(2005) women as well as men sometimes risk their own lives in order to
prevent the injury, abuse, or death of their mates or children (Buss, 2005).
3) Inflicts costs on Intrasexual Rivals :
Having an a ccess to the valuable members of the opposite sex is critical to
survival and reproduction. A Cost inflicted on the rival of the same sex
can add to the potential benefits to the perpetrator. Aggression is therefore
used as a strategy to make the same sex rival less desirable. The intensity
of the aggression may range from verbal remarks to extreme physical acts
such as killing.
4) Negotiate status and Power Hierarchies :
Literature on evolutionary psychology sheds light on how aggression can
be used as a m eans to establish oneself in the social system or to increase
one’s power in existing societal structure. Putting oneself in danger to kill
the enemies is often regarded as an act of bravery. Men who put
themselves in danger in warfare to kill enemies are regarded as brave and
courageous and consequently experience an elevation in their status within
the group (Chagnon, 1983; Hill & Hurtado, 1996).However this strategy
does not work for all the groups all the time. Aggression in some groups
can result in de cline in status.
5) Deter Rivals from future aggression :
A reputation of aggression can be used as a strategy to deter others from
co-opting one's valuable resources. Establishing oneself as the aggressor
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113 Social Behavior and Specific Topics - I resources. For example, We would not ever think of stealing anything
from a Don.
6) Deter Long term Mates from sexual infidelity :
Past reseach has indicated that Male sexual jealousy is the leading cause or
precipitating context of spou sal battering (Buss & Duntley, 2011; Daly,
Wilson, & Weghorst, 1982). A sizable number of research from shelters
for battered women indicates that extreme jealousy on the part of their
husbands or boyfriends is the key cause of the beating (Dobash & Doba sh,
1984). Men use aggression as a means to discourage women from
partnering with other men.
7.2.1 Why are men more violently aggressive than women?
An ample amount of cross cultural research unequivocally shows that men
are Often the perpetrators and als o the victims of the violent crimes. We
must make an attempt to understand what are some explanations
accounting for the same.
The model of intrasexual comepetition or competition between same sex
rivals is one such explanation. There is a difference in m inimum
obligatory parental investment as a function of sex. Men often make
minimum obligatory parental investment and hence can produce more
offspring than females can. Females are seen as a limited valuable
resource particularly in the species where femal es invest much more in the
offspring than the men do. This discrepancy leads to differences in the
variances in reproduction between the sexes. Research evidence show that
Selection often favors riskier strategies (including intrasexual competition)
within the sex that shows the higher variance.
Let us now move to understand aggression in females. If the earlier
discussion creates an impression that females do not engage in any form of
aggression, that is certainly not true. Women typically are involved in less
risky and less violent forms of aggression than do men. According to
research conducted by (Buss & Dedden, 1990; Campbell, 1993, 1999)
women may vilify the physical appearance of their rivals by using
derogation as a strategy.
As put by Campbell, wome n need to place a higher value on their own
lives than do men on theirs, given the fact that infants depend on maternal
care more than on paternal care.
7.3 EMPIRICAL EVIDENCE FOR DISTINCT ADAPTIVE PATTERNS OF AGGRESSION The empirical evidence with no ambi guity shows that men engage in
aggression more than women. With this most obvious prediction we
would also look at the other possible combinations of aggression where
reverse also might be true.
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114 7.3.1 Evidences for sex differences in same sex aggression
Let us now move to understand and explore the factors accounting for sex
differences in same sex aggression.
1) Body Differences in Design for Combat :
Natural sex differences in the body takes us back to the long evolutionary
history of male aggression. R esearch evidence certainly shows that men
surpass women in terms of overall physical strength. According to a
documented research finding, Compared to women, men have 61 percent
more total muscle mass. In addition to that men as compared to women
have 75 p ercent more upper arm muscle mass and 91 percent greater
upper body strength. They have taller and heavier bodies, thicker jaw
bones, thicker skin, stronger bones, greater bone density in their arms,
higher muscle - to-fat ratio. They generally have broade r shoulders that
makes it easy for them to use a weapon (Lassek & Gaulin, 2009; Sell,
2012). As compared to women, Men show greater interest in using their
bodies in physical competition often resulting in engagement of activities
such as boxing, wrestlin g, ultimate fighting, mixed martial arts, and high -
impact tackle football. (Deaner et al., 2012).
2) Result of a Meta -Analysis of Sex Differences in Aggression :
The result of a number of meta -analysis studies conducted both previously
and recently paints a clear picture of Aggression in males. All the studies
retain and further support the past evolutionary prediction that men engage
in aggression more than women.
In 1986, Psychologist Janet Hyde conducted a meta -analysis of studies of
the effect sizes for sex differences in different forms of aggression (Hyde,
1986). Before discussing the results of meta -analysis studies let's briefly
discuss the concept of an effect size. An effect size, in this context, refers
to the magnitude of the sex difference which can be understood as
(0.80,large), (.50 medium) and (.20 small). The effect sizes for various
forms of aggression are averaged across dozens of studies and they are as
follows: aggressive fantasies (.84), physical aggression (.60), imitative
aggression (. 49), willingness to shock others in an experimental setting
(.39). The data shows greater male scores on aggression.
3) Same -Sex Homicides :
One way to study the pattern of aggression is by considering the rate of
homicide in a particular culture. One such attempt was made by Daly and
Wilson in 1988. They compiled same -sex homicide statistics from thirty -
five different studies. These studies represented a broad span of cultures
from downtown Detroit to the Basoga of Uganda. Here it is important to
understand that the rate of homicide differs widely from culture to culture.
Therefore the most useful way to compare the sexes is to calculate the
proportion of same -sex homicide committed by males (i.e., the percentage
of same -sex homicides that are male –male homi cides).A subset of
statistics is shown in Table 7.1. From the data it is clear that the rate at munotes.in

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115 Social Behavior and Specific Topics - I which same sex homicide rates for men are necesarily higher than same
sex homcide in females.
As Daly and Wilson puts it,“Indeed there is no evidence that the w omen in
any society have ever approached the level of violent conflict prevailing
among men in the same society” (Daly and Wilson, 1988).
Table 7.1 Same -Sex Homicides in Different Cultures Location Male Female Proportion Male Canada, 1974–1998 2965 175 .94 Miami, 1925–1926 111 5 .96 Detroit, 1972 345 16 .96 Pittsburgh, 1966–1974 382 16 .96 Tzeltal Mayans, Mexico, 1938–1965 37 0 1.00 Belo Horizonte, Brazil, 1961–1965 228 6 .97 New South Wales, Australia, 1968–1981 675 46 .94 Oxford, England, 1296–1398 105 1 .99 Scotland, 1953–1974 172 12 .93 Iceland, 1946–1970 10 0 1.00 Denmark, 1933–1961 87 15 .85 Bison-Horn Maria, India, 1920–1941 69 2 .97 !Kung San, Botswana, 1920–1955 19 0 1.00 Congo, 1948–1957 156 4 .97 Tiv, Nigeria, 1931–1949 96 3 .97 Basoga, Uganda, 1952–1954 46 1 .98 BaLuyia, Kenya, 1949–1954 88 5 .95 Jol Uo,Kenya 31 2 .94
Source: Daly, M., & Wilson, M. (1988). Homicide. New York: Aldine de
Gruyter. Copyright © 1988 by Aldine de Gruyter. Reprinted with
permission.
4) Same -Sex Bull ying in Schools :
Aggression may not always be seen in an extreme form such as
aggression; milder forms of aggression are also seen, often in school
settings such as bullying.
One research was conducted to understand the patterns of bullying by
Ahmad & Smi th in 1994. The sample involved 226 middle school
children, ranging between eight to eleven year old and 1,207 high school
students ranging from eleven to sixteen years old. An anonymous
questionnaire was given to participants which asked the following
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116 often he or she had accompanied others in bullying others at school, and
the particular forms or type the bullying .The researchers concluded that
significant sex differences were ob served on all measures.
With respect to bullying others, 54 percent of middle school boys and 34
percent for same -age girls reported to have engaged in bullying. Whereas
for the older -aged high school students, 43 percent of the boys and 30
percent of th e girls reported bullying.
Researchers further examined sex differences in violent aggression. A
significant sex difference was observed for type or form of bullying. In the
high school student sample, 36 percent of the boys and 9 percent of the
girls repo rted being physically hurt, such as being hit or kicked, by a bully.
Another finding supported our earlier evolutionary hypothesis that
aggression can be used as a strategy to co -opt the resources from others.
With respect to losing their belongings, 10 pe rcent of the boys and 6
percent of the girls reported to have lost their belongings as it was taken
by someone. Interestingly girls surpassed boys in two measures of
aggression. With respect to verbal aggression, 74 percent of the girls and
57 percent of the boys reported that others had called them nasty names. It
was also observed that girls spread rumors about other girls and most often
used nasty names were as follows: “bitch,” “slag,” “slut,” and “whore.”
The findings also indicated that such type of bullying was common among
high school girls but not among the middle school students. Derogating
the same sex rival might be used as a strategy in intrasexual mate
competition in order to solve the adaptive problems.
Series of research conducted cross -culturally have produced similar
findings. One such study was conducted in Turku, Finland. Researchers
involved a sample of 127 schoolchildren who all were fifteen years old.
The researchers used the techniques of peer nomination and self -report
(Bjorkqvist, L agerspetz, & Kaukiainen, 1992). Let us now understand the
findings of the experiment in brief. Direct Physical aggression ( tripping,
taking things from another, kicking and striking, seeking revenge in
games, and pushing and shoving) was seen more in boys than in girls. The
rate of aggression in Boys was more than three times the rate of
aggression in girls.
With respect to Indirect aggression (gossiping, shunning another person,
spreading vicious rumors such as revenge, breaking contact with the
person, a nd befriending someone else as revenge) the reverse was true.
The rate of Indirect aggression in fifteen -year-old girls was approximately
25 percent higher than the same -age boys.
In summary we can say that ample amount of research continues to
support th e earlier evolutionary predictions and concludes that overall the
percent of aggression is higher in males than in females and females are
more likely to use less violent forms of aggression than males.

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117 Social Behavior and Specific Topics - I 5) Aggression in an Australian Aboriginal Community :
Anthropologist Victoria Burbank studied a community called Mangrove of
roughly 600 Australian aborigines. Researcher recorded a data of 793
aggressive episodes, some through her own observation and few as
reported by other residents. She further categori zed these episodes and
assessed sex differences in frequency within each category. It was
concluded that men overall used more dangerous forms of aggression than
women did. Further she also examined sex differences in aggression by
using any weapon (knife, gun, spear). Of ninety three cases in which the
weapon was used, ninety percent of the episodes were committed by men
but women only accounted for 3 percent of cases.
6) The Young Male Syndrome :
From the above discussion so far we have learnt that men ar e more likely
to use riskier and violent strategies than women. However, this finding
needs to be understood with caution as the research evidence also shows
that not all men use aggressive techniques always. This finding calls for an
explanation for same sex variation.
One explanation comes directly from the empirical investigation
conducted by Wilson and Daly (1985) who called this as the “young male
syndrome.”. A large sample was drawn from the United States in 1975 and
homicide rates by age and sex of the victim are shown in figure (7.1). Let
us briefly look at the findings discussed below.
As it can be seen in the figure, both men and women do not differ in the
likelihood of becoming homicide victims up to the age of ten. The pattern
however changes fr om adolescence. With the start of adolescence the
victimization of men begins to hike and peak is observed at mid -twenties.
The statistical data indicates that at this age men are six times more likely
to become the subject of homicide than women. Noticeab ly the rate of
victimization does not remain the same afterward. A steady drop is
observed in the rate of men’s victimization post mid -twenties as they
avoid the use of risky strategies.
Figure 7.1 Homicide Victimization Rates by Age and Sex for the
Unite d States in 1975.
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118 Source: Wilson, M., & Daly, M. (1985). Competitiveness, risk -taking,
and violence: The young male syndrome. Ethology and Sociobiology, 6,
59–73. Copyright © 1985, with permission from Elsevier Science.
The young men syndrome also accou nts for findings from episodes of
violent conflicts from collective aggression such as riots and gang fights.
Across many countries and states it has been observed that there is an
association between percentage of coalitional aggression and percentage
of males in the age group of fifteen to twenty -nine, as this group accounts
for most coalitional aggression.
7.3.2 Context triggering Men’s aggression against Men :
Aggression ranges from mild to severe, and homicides represent the most
extreme form of aggres sion and violence. Men are most often the
prep[arators as well as the victims of the violence. Let us now explore
some causal factors that underlie male - male homicide.
1) Marital and Employment status :
Having access to valuable resources is critical to survival and
reproduction. Therefore lack of such resources and failure to attract long
term mates may be one of the causal factors linked with male -male
homicide. The findings of various studies indicate that victims and
perpetrators share the same cha racteristics. A study by Wilson & Daly
(1985) of Detroit homicide revealed that 43 percent of the victims and 41
percent of the perpetrators were unemployed. Similarly with respect to
marital status, 73 percent of the male perpetrators and 69 percent of th e
male victims were unmarried.
2) Status and Reputation:
Research evidence suggests that there is a link between reputation and
aggression. One laboratory experiment proved it scientifically.
Participants in a study were provided with status cues (Imagine being
graduated from college) which would act as a prime. Upon priming they
were told that there are other two competitors competing for a prestigious
job. They were asked to imagine the other competitor did some careless
act (spilling drink on table) and did not apologize. Then they were asked
the question, how likely are they to insult the opponents.(Insult, hit, push,
or get “in the face” of the rival). It was found that compared to women,
men significantly reacted to the direct aggression when they were primed
with status cues. Series of experiments on tribes in the Ecuadorian
Amazon confirmed that Status and warriorship are highly correlated.(John
Patton ,1997, 2000)
3) Sexual Jealousy and Intrasexual Rivalry :
Evolutionary literature suggests that exua l jealousy is a significant factor
in triggering same -sex aggression and homicide. A summary of various
studies of same sex killings involving love triangle shed light on the same.
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119 Social Behavior and Specific Topics - I were male –male homicides and only 8 killings percent were female –
female homicides.
7.3.3 Causal contexts Triggering Women’s aggression against
Women :
Females also uses number of strategies against other same sex competitors
mainly to maintain her mate’s lo yalty and mate’s resources and protection.
Females often use social exclusion to get rid of female competitors
through verbal aggression.(Benenson, Hodgdson, Heath, & Welch, 2008).
A study by Buss & Dedden, (1990) concluded that women were more
likely to use verbal derogation as a strategy to fend off their competitors
than did men. The competitors were derogated against the physical
appearance (Calling them fat, ugly, mocking body shape and size) and
sexual promiscuity. sexual promiscuity as a tcatic was context dependent.
For men the dimension of sexual promiscuity was only significant while
looking for a long term mate and not a short term mate.(Buss & Schmitt,
1993).
In summary, females prominently use aggression to attract the potential
mates and to secure the resources from mates and to fend off the
competitors.
7.3.4 Contexts Triggering men’s Aggression against women :
So far we have seen that men are more likely to aggress against other men.
Let us now understand certain factors that might cause men to aggress
against women. Sexual jelousy appears to be the leading cause for such
aggression across cultures.(Daly & Wilson, 1988) In one study involving
battered women, It was observed that fifty -seven of sixty battered women
admitted extreme jealousy an d possessiveness on the part of their
husbands (Hilberman & Munson, 1978). Men who typically engage in
spousal homicide or aggression are triggered by following factors. One
such factor is suspicion of sexual infidelity and second being suspect of
terminat ion of relationship by a women. Age of the women also plays a
role as age is a powerful cue indicating girls reproductive value.
Therefore, Young wives and girlfriends stand a higher chance of being
killed than older ones (Daly & Wilson, 1988; Shackelford, Buss, &
Weeks -Shackelford, 2003).
7.3.5 Contexts Triggering Women’s Aggression against Men :
It might seem rare but the research suggests that under certain
circumstances women as well inflict violent aggression on the men. Let us
now briefly look at certa in factors that can cause women to aggress against
men. Women most often use aggression as a last resort in order to save
oneself or to defend against the attack. The factors accounting for the
aggression are as follows: Male sexual jealousy, saving onesel f from an
enraged husband over a real or suspected infidelity, prolonged history of
physical abuse. (Daly & Wilson, 1988; Dobash et al., 1992). Spousal
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120 7.4 CONFLICT BETWEEN SEXES Donald Symons (1979) very correctly said that In every age the battle of
the sexes is largely a battle over sex. Men and women must cooperate with
each other for survival and reproduction. In this section we shall discuss
some of the major forms of sexual conflict such as conflicts over the
occurrence and timing of sex, sexual aggression and defenses against
sexual aggression. Sexual conflict may be defined as “a conflict between
the evolutionary interests of individuals of the two sexes”(Parker, 2006, p.
235).
7.4.1 Str ategic Interference theory :
Human conflict occurs at many levels and in many forms. Research has
suggested that conflict between sexes typically occurs as a function of use
of different evolutionary strategies. We have seen that use of strategies
differ as a function of sex. With respect to short term mating men more
than women have evolved strong desire for sexual variety whereas women
have evolved to be more discriminating. These conflicting desires cannot
be fulfilled simultaneously hence result in a phe nomenon of strategic
interference. If a woman refuses any sexual advancement until some
emotional commitment from a man is made and if a man still persists in
his sexual advances inspit of refusal from a woman then this results in
interference in women’s s trategy. Strategic Interference phenomenon is
applied to a number of situations including timing of sex, at workplace in
form of sexual harassment, in dating situation through deception, sexual
infidelity in a marriage etc. Research has also indicated tha t negative
emotions (Anger, distress, upset) are evolved to solve the adaptive
problems of strategic interference as these emotions alert people to the
sources of distress thereby ensuring a prompt action.
In summary, Strategic interference occurs in a sit uation where a person
employs a particular strategy to achieve a goal and another person
obstructs the successful enactment of that strategy.
7.5 CONFLICT ABOUT THE TIMING AND OCCURENCE OF SEX Failure to agree upon the timing and occurence of sex is one o f the leading
cause of conflict between men and women. This prediction was supported
through a number of studies. One such study involved 121 college
students who were asked to maintain a diary, indicating their dating
activities over a span of four weeks. Findings of the research revealed that
around 47 percent students reported one more incidence of disagreement
about their desired level of sexual intimacy (Byers & Lewis, 1988)
7.5.1 Conflict Over Sexual access :
In this section we shall discuss some comm on conflicts that occur between
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121 Social Behavior and Specific Topics - I 1) Inference about sexual intent :
Another source of conflict between men and women is the incorrect
inference of sexual interest. Men often incorrectly infer the sexual interest
on the part of women when it may not ex ist. It has also been documented
that when men are in doubt they are more likely to infer sexual interest
and occasionally may act on those inferences. A series of studies have
suggested that men are more likely to exhibit sexual misperception bias
and may misinterpret simple friendliness or smiling as cues to sexual
interest. (Perilloux, Easton, & Buss, 2012). A real world demonstration of
the same was documented by Browne in (2006). A supermarket chain had
implemented a ‘Superior customer service’ Progra mme in which the
employees were asked to smile at and make eye contact with the
customers. However, it was observed that male customers misinterpreted
these gestures by female employees as sexual cues, resulting in sexual
comments or even stalking. This mi sinterpretation or bias often results in a
conflict.
2) Deception about Commitment :
Research has shown that men often intentionally deceive women about
emotional commitment. The cost of being deceived by a partner is more
heavily paid by a woman than a man resulting in untimely pregnancy and
unaided childrearing. Since the cost to be paid is very high, women must
be vigilant about the cues of deception. Research suggests that women use
naturally evolved strategies to protect oneself against deception. Women
are more likely to take extended time, energy and commitment before
consenting to sex as it allows more time for stringent assessment.
3) Cognitive Biases in Sexual Mind Reading :
We often make inferences about a number of things including others
intenti ons and emotional states. How attracted is he to her? How
committed is she to him? Is he being friendly or is it something else?
However our inferences may not always be correct and we may go wrong
sometimes. Some common miss -inferences includes, Misperce ption of
sexual interest when it does not exist, or being unaware about the true
romantic yearnings when it does exist. According to Error management
theory (EMT), It is important to understand that the cost -benefit ratio of
the above two circumstances are not identical. (Haselton, 2003; Haselton
& Buss, 2000, 2003;Haselton & Nettle, 2006). In case of fire alarms which
are set to detect any hint of smoke, the cost of failure to detect the real fire
is much heavier than the occasional false alarms. The asymm etry of cost -
benefit if occurs in evolutionary time creates tension and produces
systematic bias.
The first is sexual overperception bias in men where men appear to
incorrectly infer sexual interest on the part of women when it does not
exist.
The second s uch bias is the commitment skepticism bias in women
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122 men’s actual level of romantic commitment to her early in courtship. A
study showed that this bias was present in young women but no t in older
women (Cyrus et al., 2011).
EMT provides a newer perspective on problems faced by humans in
mating, and it further suggests that some errors reflect functional
adaptations rather than actual problems in the psychological system.
4) Sexual withh olding :
Women often use the strategy of sexual withholding exercised through
acts such as being sexually teasing, saying no to intercourse, and leading a
man on and then stopping him. By doing so women preserve their ability
to choose, allowing only those men of high quality who will be ready to
invest emotionally. This way women only allow sexual access to the men
ready to make heavy investment. Women’s strategy of withholding the
sexual access and men’s strategy to have it sooner crates the conflict
betwe en sexes.
7.6 SEXUAL AGGRESSION In this section we shall discuss different forms of sexual aggression by
men and what strategies women use to guard against it.
7.6.1 Sexual Harassment :
As put by Terpstra & Cook, (1985) Sexual harassment is defined as
“unwanted and unsolicited sexual attention from other individuals in the
workplace” .The conflict or disagreement between the sexes to have
sexual access at times result in workplace in form of sexual harassment.
Sexual harassment ranges from mild (unwanted sta ring and sexual
comments) to severe acts (physical violations, such as the wanted touching
of breasts, buttocks, or crotch) .Victims of sexual harassment are typically
women who are young, physically attractive and single. Women over age
forty -five are fa r less likely than younger women to experience sexual
harassment (Studd & Gattiker, 1991). Reactions to sexual harassment
support the assumption of strategic inference theory as it results from a
difference between men’s and women’s evolved psychologies (B rowne,
2002, 2010).
7.6.2 Sexual exploitation and cues to sexual exploitability :
A new research has shed light on men’s strategies of sexual exploitation
and women’s co -evolved defenses to prevent it. Researchers have
identified three types of cues to sexu al exploitability and they are as
follows. Psychological cues (e.g., shyness, low cognitive ability,
permissive sexual attitudes), incapacitation cues (e.g., intoxication,
fatigue), and physical cues (e.g., small body size, shorter walking gait)
(Goetz, Ea ston, Lewis, & Buss, 2012). Those men who use sexual
exploitation as a strategy have adaptations to identify observable cues in
women and that further indicate ease of sexual exploitation. Women
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123 Social Behavior and Specific Topics - I sexually exploitability as a tactic to pursue their mating goals such as
attracting highly desirable mate for short term relationship (Goetz, Easton,
& Meston, 2014, Buss, 2003).
7.6.3 Sexual Aggressiveness :
Sexual aggressiveness is one of the risky strategies used by men which
minimizes their investment for sexual access, but also costs them high in
form of retaliation and damage to reputation. In one study where women
were asked to rate 147 upsetting actions men could do to them on a sc ale
of 1 (not at all upsetting) to 7 (extremely upsetting) ,women gave a rating
of 6.5 to sexual aggression. However, men often underestimate how
unacceptable sexual aggression is to women.
7.7 JEALOUS CONFLICT We have so far reviewed problems in choosing a mate. However, it is also
equally important to retain the mate once chosen to fulfill the reproductive
potential. There are several threats to mate retention. The first threat is the
presence of mate poachers and the second threat is mate’s infidelity.
Evolutionary psychologists have stated that the emotion of jealousy has
evolved to deal with such adaptive problems. Sexual jealousy promotes
vigilance by signaling men to circumstances in which his partner might be
unfaithful. It also enables men to incre ase their efforts to fulfill their
partner's desires to have less incentives to stray.
7.7.1 Sex differences in Jealousy :
Many studies have explored the sex differences in psychology of jelousy.
One such study conducted by Buss et al (1992) revealed that men are more
likely to give more weight to cues to sexual infidelity, whereas women to
give relatively more weight to cues to a long -term diversion of investment,
such as emotional involvement with another person . In a test of
hypothesized sex difference involving 511 students, asked participants to
compare two distressing events: (a) their partner having sexual intercourse
with someone else or (b) their partner becoming emotionally involved
with someone else. 83 percent of the women but only 40 percent of the
men reported their partner’s emotional infidelity more upsetting. In
contrast, 60 percent of the men and only
17 percent experienced their partner’s sexual infidelity as more
distressing. In a subsequent study conducted in psycho -physiological
labora tory, revealed that the men became more physiologically distressed
by the sexual infidelity whereas exhibited greater physiological distress at
the thought of emotional infidelity (Buss et al.1992).
7.8 SEX DIFFERENCES IN THE TACTICS OF MATE RETENTION Psyc hological mechanisms evolve only if they are translated into behavior
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124 ● Deter Mate Poachers
● Deter a partner from committing infidelity
● Lower the odds that the partner will defect from the relationship
It is important to note that mate retention techniques can range from
vigilance to violence.
Strategies commonly used by Men
According to several studies exploring sex differences in mate retention
techniques have found out that men are more likely to use following
techniques.
1) Concealing a partner: Exercised by taking a partner to a party where
other men are present or i nsisting that she spend all of her free time
with him.
2) Threats and violence: Threatening to hit a man who is making
moves on his partner or picking a fight with a man interested in her
3) Resource display : buying the partner jewelry, giving her gifts, and
taking her out to expensive restaurants
4) Submission and self -abasement: groveling and saying that they
would do anything their partner wanted to get the partner to stay in
the relationship.
Strategies by women
Commonly used techniques of mate retenti on by women are as follows.
1) Enhance their appearance: making up their faces, wearing the latest
fashions, and making themselves “extra attractive” for their mates.
2) Inducing jealousy : by flirting with other men in front of them,
showing interest in other men to make their partners angry, and
talking with other men to make their partners jealous
However it is important to note that these strategies are not always used by
all women all the time.
7.8.1 Context Influencing Mate retention Strategies :
Seve ral contexts influencing Mate retention strategies are given below.
1) Reproductive Value of the Wife :Effects of Age and Physical
Attractiveness
There are two powerful cues to a woman’s reproductive value and fertility
are her youth and physical attractiv eness. These two qualities appear to be
highly desirable to men across cultures (Buss, 1989a; Kenrick & Keefe,
1992). A study conducted by reported that men married to younger women
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125 Social Behavior and Specific Topics - I Similar findings were also reported by Graham -Kevan and Archer
(2009).It was found that men who mated to fertile women exercised more
economic, threatening, and intimidating forms of controlling behavior, and
were more likely to isolate them from social contact with others.
2) Ovulation Status of the Woman :
Several studies have reported that men seem to increase their mate -
retention efforts at precisely this time in their partner’s menstrual cycle
(Gangestad, Thornhill, & Garver -Apgar, 2005; Haselton & Ga ngestad,
2006; Pillsworth & Haselton, 2006).
3) Income and Status Striving of the Husband :
Women’s mate retention tactics were hypothesized to be a function of
husband’s income and status striving. Status striving refers to the degree to
which the husband devotes his efforts to getting ahead in the status and
work hierarchy (Buss & Shackelford, 1997c).
7.8.2 Destructive side of mate retention: Violence towards partners :
Have you ever wondered why one would commit violence against a
partner? As discussed ear lier, use of violence is often used as a strategy
which serves several functions. Use of violence and threats by men helps
to restrict a partner’s autonomy thereby reducing the odds that the partner
will commit infidelity or defect from the relationship (Wilson and Daly
,1996).
Spousal homicide is the most destructive form of violence towards a
partner. In case of spousal homicide, even the perpetrator bears a heavy
cost as he loses an access to the valuable resource hence this continues to
puzzle the ev olutionary researchers. Age also plays a role as Young and
attractive women might be more vulnerable to violence from their
partners. Research studies have confirmed this prediction. The wives who
are at greatest risk of being killed by their husbands are in their teenage
years; the lowest rates of spousal homicide are among postmenopausal
women (Daly & Wilson, 1988).
7.9 EVOLUTION OF MORALITY So far we have explored the topic of aggression which has received
considerable research attention. Now let's discu ss the topic that has
received very less attention from evolutionary psychologists that is
Morality. Moral behavior is indeed important in our day to day lives.
Before exploring morality in detail let’s explore some philosophical
issues. Naturalistic Falla cy is one such fallacy. It argues that just because a
behavior is found to occur ‘naturally’ it doesn’t follow that the behavior is
somehow ‘right’ or ‘good. It is implied in this fallacy that ought cannot be
derived from it.

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126 7.9.1 Free -riders and the soci al contract :
Human beings as social animals accept a number of cooperation strategies
for long term gain. One such model is Social contract. Social contract can
be implicit or explicit in which an individual member agrees to bear a
short term cost to immed iate personal benefit in order to gain long term
benefit through the means of cooperation. These societal systems are
always susceptible to free riders, those who obtain some benefit without
effort or cost. This can destabilize the functioning of the group and hence
free riders pose a serious problem. Needless to say those human beings
have evolved a number of special mechanisms to detect cheating
Human beings are predisposed to be sensitive to detect or identify social
cheating. A number of studies conduct ed in this domain have confirmed
this prediction.
Leda Cosmides and John Tooby conducted series of experiments using
Wason Selection Task (abstract logic task, originally developed by the
psychologist Peter Wason conducted with an aim to study people’s
intuitive understanding of scientific reasoning) The task is as follows :
● The subjects are presented with 4 cards with a rule such as, ‘If a card
has Cards vowel one side it always has an even number on the reverse
side’
 After the presentation of cards, subjects asked to say which card or
cards they would turn over to test the validity of the rule.
 A result of this experiment revealed that only 25 percent of the
subjects could answer the test correctly.
 Cosmides and Tooby however showed that when the identical task
was formulated (‘Only people older than 18 years are all owed to drink
beer’) and presented in a form of social contract 75 percent of the
subjects could provide the correct answer.
 Cosmides and Tooby argued that the findings concluded that we have
a specialized cognitive module that was extremely sensitive t o social
cheating.
 These findings and the interpretation spurred a lot of debate in the
field.
Needless to say that people seem to be particularly sensitive to social
cheats. The experimental evidence shows that people are more likely to
remember a perso n's facial features if they were made aware about any
cheat committed by that person. Similar Group identity or group
membership may also help people to believe that another person will
cooperate as a sense of obligation. Group identity is explicitly displ ayed
by clothing and hairstyles, religion and other beliefs or dialect and styles
of behavior. Similar dialects can also be effective in controlling free
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127 Social Behavior and Specific Topics - I people to cooperate with us, we must have a reputation of being honest.
This has also been tested empirically.
7.9.2 Strong reciprocity and the prosocial ‘instinct’ :
In a series of experiments, Fehr and his collaborators explored the
interesting phenomenon of Strong reciprocity a nd the prosocial ‘instinct’
through different games. Let's now look at some of the experimental
findings in brief.
● The games used in the experiments were one shot games which means
only a single round is played.
● All the individuals in the game remain anonymous and genetically
unrelated to ensure that findings cannot be explained by the theory of
reciprocal altruism and kin selection.
● Findings of the experiment suggested that a significant proportion of
people repay gifts willingly and also punish individuals who violate
fairness and co -operative norms.
● Fehr has termed the behavior as ‘Strong reciprocity’ in whic h an
individual willingly sacrifices the resources for both rewarding the
fair behavior as well as to punish the unfair behavior in spite of no
present benefit nor future economic rewards for the person.
● Another notable finding from these experiments was that not all
individuals play fair and some use a strictly selfish strategy.
● In this kind of game one factor significantly influences the findings,
that is whether individuals believe they will be punished for non -co-
operation.
● When there is no punish ment for non -cooperation, low cooperation is
observed and it even tends to decline with each successive round.
● Some of the later studies also documented that Willingness to punish
is not unconditional as willingness to punish decreases when the costs
become too high.
● Herb Gintis, through a mathematical model, showed that through
evolutionary history human beings have faced several extinction
problems, (floods, famines and other environmental catastrophes) on a
regular basis and under such circumstances groups with high numbers
of reciprocating increases the survival chance of the group. Further it
showed that the balance between the two forces means that, at
equilibrium, both selfish individuals and strong reciprocators co -exist.
7.9.3 Social embeddedne ss:
Human decisions are always embedded in a social context. Most of the
studies highlighting the importance of social context have conducted ‘The
‘Ultimatum Game’. Let’s understand this game in brief. This game is
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128 is asked to make an offer to share it with a second player who is generally
anonymous. The second player has two options, Either he can accept the
offer thereby splitting the money as per the offer or he can refuse it.
Studies showed that when conducted in modern Western societies, offers
typically average 50 per cent of the initial stake, which further suggest that
the player making the offer is responding to expectations of fairness
although not purely economical. In contr ast when the same game is
conducted in traditional societies, average offers ranged between 26 –58
percent. Two factors explained the variance. One was the extent to which
the group’s economic production required co -operation (Limited
cooperation to larger cooperation) the extent to which the society
concerned was integrated into (and thus dependent on) a market economy.
Patterns of rejection also revealed the importance of social institutional
factors. It was revealed that, In western subjects only offers b elow about
30 percent of the stake are rejected implying that something is better than
nothing. In contrast traditional societies showed much greater variability.
In some cases it was observed that only offers below 16 percent were
rejected, whereas in som e others cases only offers above 70 percent were
accepted.
7.10. EVOLUTION OF ART Do human beings only engage in activities that are critical to survival and
reproduction? Why do we have several activities which are not directly
related to survival? Why do we spend our time enjoying movies, enjoying
sports or learning any new art? What motivates us to pursue our hobbies?
In this section we will try to explore some evolutionary explanations of the
same. Evolutionary psychologists have come up with two explan ations to
account for the same.
1) Display Hypothesis :
As put by Miller(1998) “Culture is “an emergent phenomenon arising
from sexual competition among vast numbers of individuals pursuing
different mating strategies in different mating arenas”. Further M iller
suggested that cultural displays by male increases sexual access. This
might explain why men have produced more art and literature than
women. Further evidence for cultural display comes from the pattern of
age distribution of cultural displays as th e majority of art and music is
created by men in young adulthood (intensely engaged in intrasexual mate
competition). However critics report that display hypothesis is not
sufficient to explain why there is a variation in the content and why some
people en joy solitary enjoyment of art and music in absence of cultural
display.
2) Explanation by Pinker :
“Let people take pleasure in shapes and colors and sounds and jokes and
stories and myths” (Pinker, 1997, p. 523). According to Pinker, the answer
lies in ev olved mechanisms in the mind. He further suggested that Humans munotes.in

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129 Social Behavior and Specific Topics - I have learned to artificially activate existing mechanisms by inventing
cultural products that mimic the stimuli for which the mechanisms were
originally designed. For eg. Color vision for locat ion ripe fruit, can be
activated by making the paintings that imitate these patterns. Pinker has
made a similar explanation for patterns of music. He suggested that music
is sensitive to six mental faculties.
● Language Such as lyrics from songs
● Auditory scene analysis : According to this, we must segregate sounds
coming from different sources, such as a animal call in a noisy forest
● Emotional calls (Such as whining response or crying, moaning,
baying, and cheering are used as metaphors to describe mus ical
passages)
● Habitat selection such as thunder, rushing water, growls, and other
sounds might signal safe or unsafe environments
● Motor control (e.grhythm, a universal component of music, mimics
the motor control needed for a variety of tasks, includ ing running and
chopping, and signals qualities such as urgency, laziness, and
confidence.
In summary, According to this argument by Pinker, the patterns of music
which we find pleasurable, are those that artificially mimic natural stimuli
that our evolve d mechanisms were designed to process. This hypothesis is
not only limited to art and music but also to movies and fictions. The
plots, stories, narration of comedy or tragedy activates pleasurable
sensations by triggering a host of evolved mechanisms. No wonder why
popular and successful movies/novels contain patterns of intrasexual
competition, mate choice, romance, and life -threatening hostile forces of
nature.
7.11 EVOLUTION OF EMOTION In this section we would illuminate our understanding about the mos t
interesting topic in evolutionary psychology that is evolution of emotion.
The topic of emotion has been studied from multidisciplinary perspectives.
The research surrounding emotions dates back to Darwinian Theory.
Emotions are special modes that are sh aped by natural selection. As put by
Darwin, evolution shaped not only the physical characteristics of an
organism but also its mental processes and behavioral repertoires.
An evolutionary account of emotion takes into consideration how
emotions came to ex ist. Emotions are evolved to coordinate an organized
response to deal with an adaptive challenge. For example, Presence of a
predator, initiates an emergency response on the part of a potential victim.
How many emotions exist? Can we categorize emotions s imply under
positive and negative domains ? Evolutionary psychologists, through years
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130 simple dichotomous categorization while some argue for complex
understanding of multiple emot ions. Irrespective of the stand all the
theorists agree that valence and intensity are necessary qualities of
emotions (Smith & Ellsworth, 1985). The ability to detect emotions
initiates appropriate responses. For. eg Excessive heat (signaling danger)
can initiate escape response. Different theorists have listed several basic
emotions, but all include fear and anger, and most also include joy and
sorrow. Some theorists have proposed a few more additions to the list of
emotions.
As put by Cosmides and Toob y, selection has shaped thousands of discrete
domain -specific mental modules to deal with different situations
(Cosmides & Tooby, 1994) and that emotions are superordinate programs
which coordinate the modules (Cosmides & Tooby, 2000).
Evolutionary psychol ogists reject the idea of existence of sharply distinct
emotions and sharp distinction between emotions and moods. They
believe that both are special states which are evoked in these situations as
a tactic to increase fitness.
7.11.1 The Origins and functi ons Different Emotions
Years of investigation in the field of emotional research have reached
several conclusions.
1. Emotions do not have clear boundaries: There is an overlap in both
the characteristics of situations and the patterns of response that are
adaptive responses. For example, given two similar situations such as
confronting a snake and confronting a bear, adaptive responses also
would be the same.
2. The clear taxonomy of emotions may not exist.
3. No specific description of emotions and their subtypes can be accurate
and precise.
Sometimes specific emotions are often discussed in relation to their
special functions. Emotions are often perceived as a special mechanism
through which fitness in certain situations is enhanced. Positive emotions
motivates the organism to take advantage of environmental opportunities
while negative emotions motivate the organism to save oneself from
misfortune. A response of fear to danger often motivates escape. For
example, If we confront a snake, thereby inducing f ear response, we are
more likely to run away to avoid potential threat (escape). An emotion of
disgust often initiates avoidance response or vomiting, interest leads to
exploration; lust motivates seduction and sexual intercourse; sorrow
motivates ask for help or giving up on fruitless endeavors, and so on
(Gross & Keltner, 1999; Plutchik, 2003).
Fear conditioning and classical conditioning often allows the organism to
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131 Social Behavior and Specific Topics - I adaptive benef it. Operant conditioning also offers an additional benefit as
it allows the organism to predict the likely consequences of an event.
However it is important to note that different emotions do not correspond
to different specific functions; instead, they co rrespond to the adaptive
challenges encountered in different situations.
7.11.2 Appraisal theories of Emotion :
Appraisal theory of emotion was originally put forward by Magda Arnold
in 1960. Appraisal theory argues that organisms are constantly alert to
changes in the situation that might have implications for their well -being.
It further states that emotions involve situation appraisals and
physiological response and action (Frijda, 2006). Emotions arise from
appraisal of several situations such as
● Novelty and environmental changes
● Intrinsic pleasantness/unpleasantness
● Goal obstacles or facilitators
● Unpredictability
● Agency (event caused by self, other, or circumstances)
● Controllability
● Compatibility with social norms or personal values
Appraisal theory believes that we don’t focus on concrete theories of
emotions, rather we appraise the abstract appraisals from where the
emotion arises. For example, a new element in the situation such as a tiger
elicits fear. A loud noise of lightning ma y induce fear but if the loud noise
is coming from honking it may induce anger.
7.11.3 Social Emotions :
As man is a social animal and connected to society, social emotions carry
a special significance and needs to be treated differently. Research so far
has greatly focused upon the benefits of reciprocal exchange in social
situations (Cosmides & Tooby, 1992; Fessler & Haley, 2003; Ham -
merstein, 2003; Trivers, 1971). Benefits of reciprocal exchange is often
studied using Prisoner’s dilemma, which represents a situation in which
two players who are separated and have no means of communication must
individually choose between two options : cooperating or not cooperating.
The results typically show that people play fairly on the game and try to
maximize their benefit. It has also been found out that people tend to be
generous initially and give strict responses to defections by others.
Different strategies may elicit different emotions such as Mutual
cooperation elicits friendship and trust whereas temptations to defect
induces anxiety. Defection creates guilt whereas suspicion is useful when
the other might defect; and if she or he does, anger is beneficial. Several
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132 recent work in the dom ain has focused on irrationalities on the part of
human behavior that is not in line with self -interest.
7.12 SUMMARY In this unit we began by explaining the evolutionary roots of Aggression
and how aggression is being used to solve adaptive problems, crit ical to
survival and reproduction. We then explained the sex differences in
aggression and under what circumstances both sexes might aggress against
each other. We also reviewed some common conflicts that are often seen
between sexes as a result of use of conflicting strategies. Further, some
commonly used mate retention strategies were also discussed. In addition
to aggression and conflict we discussed the evolutionary base of morality.
Human beings do not only engage in activities critical for survival as we
spend a lot of time pursuing hobbies, watching movies, doing other
activities and art.Hence we also tried to explore the evolution of art in
brief. At last we shifted our focus to the concept of emotions and then
discussed how emotions are to be und erstood from an evolutionary
perspective.
7.13 QUESTIONS A) Write long answers:
a) Discuss the use of aggression as a solution to adaptive problems in
detail.
b) Elaborate different tactics of mate retention in detail.
c) Discuss the context triggering men ’s aggression against men.
B) Write short notes:
a) Jealous conflict
b) Origin and functions of emotion
c) Sexual aggression
d) context triggering women’s aggression against women
e) Evolution of art
7.14 REFERENCES  Barkow, J. H., Cosmides, L., Tooby, J. ( 1992). The adapted mind.
Oxford University Press.
 Buss, D. (2011). Evolutionary Psychology: A new Science of Mind.
Pearson Education.
 Buss, D. (2005). The Handbook of Evolutionary Psychology. John
Wiley & Sons, Inc. munotes.in

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133 Social Behavior and Specific Topics - I  Buss, David M. Evolutionary psychology : the new science of the
mind/David M. Buss, The University of Texas at Austin. Fifth edition.
 Dunbar, R. I. M. (2005). Evolutionary Psychology: A Beginner's
Guide. One world.
 Nesse & Ellsworth (2009). Evolution, emotions, and emotional
disorders. American Psychologist, 64, 129 -139.



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134 8
SOCIAL BEHAVIOR AND SPECIFIC
TOPICS - II
Unit Structure
8.0 Objectives
8.1 Introduction
8.2 Dominance and status in non human species
8.3 Evolutionary theories of Dominance, Status and Prestige
8.3.1 Prestige signaling, altruism, and reputation
8.3.2 Leadership and followership: The service -for-prestige theory
8.4 Evolutionary theory of Sex differences in status and striving
8.4.1 Status and Sexual Opportunity
8.4. 2 Are men higher in status striving
8.4.3 Men and Women Express Their dominance thr ough Different
Actions
8.5 Dominance Theory
8.6 Social attention holding theory
8.7 Indicators of Dominance
8.8 Self-esteem as a status tracking mechanism
8.8.1 Sociometer theory
8.9 Strategies of Submissiveness
8.9.1 Sex Differences in Submissive Str ategies
8.10 Cognitive development
8.11 Modularity of Mind and innateness issues
8.12 Summary
8.13 Questions
8.14 References
8.0 OBJECTIVES After studying this unit you should be able to:
 Understand the definitions of status, Dominance and Prest ige
 Discuss what functions do these hierarchies serve.
 Understand the other side of the dominance spectrum: being
submissive
 Explore the evolutionary logic underlying the use of submissive
strategies.
 understand Cognitive Evolutionary psychology munotes.in

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135 Social Behavior And Specific Topics - II 8.1 INTROD UCTION In the later part of this unit, we will discuss how dominance hierarchies
are formed in Human and nonhuman species and what functions they
serve. We shall also focus on the sex differences in the formation of status
hierarchies. We shall also review various correlates of Dominance and sex
differences in the strategies used by men and women. Thereafter we shall
analyze the other end of the dominant continuam that is being submissive
and will explore the evolutionary logic underlying the same followed by
understanding evolutionary cognitive development and modularity of
mind in brief.
8.2 DOMINANCE AND STATUS IN NON HUMAN SPECIES As put by Robert Frank (1985), We come into the world equipped with a
nervous system that worries about rank. Why do human b eings strive to
get social recognition ? Why are people so concerned about their
reputation and honor?
Several researchers have studied and documented the existence of this
phenomenon in non -human species such as crickets. Research findings
show that cric kets often store an account of their fights with other crickets.
In addition they also remember the history of success and failure of each
such fight.(Dawkins,1989). Consecutive success allows the cricket to
emerge victorious and aggressive thereby increas ing the chances of
seeking sex from female crickets.
“Pecking Order” is one such phenomenon which explains how order is
established amongst hens. Hens initially fight with each other and
gradually understand that each hen is superior to and subordinate to other
hens thereby subsiding the fights. Once the order is established it helps
both superordinate and subordinate hens. Dominant hens gain advantage
as their rank is established and subordinate hens get advantage as they can
avoid injury by not fighting w ith the dominant hens.
All out fighting is not an effective strategy as it is costly for both victor
and the loser. Researchers further believed that subsequent behavior of
loser and victor is linked with some changes in the nervous system.
Researchers tes ted this assumption with a pair of crayfishes. Two
subordinate crayfishes were put in one territory and it was found that one
crayfish shifted from subordinate to dominant status. Their neurons were
tested two weeks later and it showed that the neuron was excited by the
serotonin. In another Trial two dominant crayfishes were put in one
territory and they proved the saying that ‘More than one male crayfish
cannot inhabit the same territory without determining who the boss is’
(Barinaga, 1996). Out of two do minant crayfishes one was forced to take a
subordinate position even though the crayfish continued to be aggressive,
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136 The dominance and status order is also evidently seen in the case of
chimpanzees. In chimps, the number of times an animal receives
submissive greets from the other animal is considered to be an indicator of
dominance. Sometimes the submissive chimp also brings certain objects
such as leaf sticks for the dominant chimp. The Dominant male chimps
often walk around and make themselves look deceptively large and heavy.
The dominant chimp gets an adaptive evolutionary benefit by having
increased sexual access to females (de Waal, 1982). A survey of 700
studies, conducted by Ellis (1995) reported that t he animals with middle to
high ranking typically get more reproductive advantage over the low
ranking animals.
Cummins documented certain characteristics of the dominance hierarchies
and they are as follows. The status hierarchies are not static as individ ual
animals continue to compete for the higher position. Injury or death of a
dominant animal, creates instability and creates a hurry to fill the void
position. Dominance is not primarily indicated by physical size but rather
social skills (Cummins, 1998, 2005).
8.3 EVOLUTIONARY THEORIES OF DOMINANCE, STATUS AND PRESTIGE In this section, we will try to understand the theoretical perspective
underlying dominance, status and prestige. With a sound base of a theory
we will try to decode what function does dom inance and status serve?
Why do people strive for prestige? How hierarchies are established in
groups and what functions do they serve? What benefits do they offer for
the dominant and subordinate members?
We need a comprehensive theory to help explain why status striving is
more prevalent in males than females. A good theory should also focus
upon the benefits that the subordinates get if any. It should also further
explain why people strive for equality at the same time and differentiate
between dominance and production hierarchies.
Dominance refers to force or threat of force. An individual may enjoy the
additional benefits or status by establishing himself as dominant through
the use of power. Prestige, in contrast, is regarded as “freely conferred
defer ence.”, and it is domain specific. Dominant individuals often induce
fear in subordinates whereas prestigious individuals evoke admiration.
8.3.1 Prestige signaling, altruism, and reputation :
Research evidence has shown that Costly signaling is found to b e
prominent in acquisition of prestige (Bliege Bird & Smith, 2005; Boone,
1998; Plourde, 2008). According to Anderson & Kilduff (2009) ,In
traditional hunter gatherer societies signaling involved throwing lavish
feasts for the group, providing meat from d ifficult -to- capture prey
animals, or displaying knowledge that is valuable to the group. In modern
societies, one may acquire prestige by making personal sacrifices
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137 Social Behavior And Specific Topics - II the tasks that ar e valuable to the group, or being generous (Andeson &
Kilduff,2009). It is important to understand in the context of prestige,
giving is highly regarded than receiving.
In one experiment people were being asked to contribute some money
(either anonymously or in the presence of the group) in order to help
needy people. Researchers then analyzed changes in the social reputation
by considering if an individual has offered or did not offer charity and
whether their behavior is observed by anonymous or by group. As
expected it was found that those people who contributed for charity
experienced a dramatic increase in their prestige and reputation when
contributions were made publicly (Bereczkei, Birkas, & Kerekes, 2007).
8.3.2 Leadership and followership: The serv ice-for-prestige theory :
Have you ever observed the functioning of any specific group? you will
realize that not all members in a group are equally dominant or eually
submissive, rather some choose to lead while others choose to follow.
What qualities of leaders are most valued by the group? In this section we
will understand the evolved strategies of leading and following and what
adaptive benefits do they offer to an individual to solve adaptive problems.
According to Van Vugt, (2006) Leaders are those w ho possess knowledge
and competence relevant to the task and they are high in intelligence, and
signal high levels of generosity by making costly sacrifices for the group.
Leaders are the ones who have special qualities to solve problems related
to group c onflict and coordination and often emerge from group
consensus.
Service -for-prestige theory of leader –follower relations states that leaders
often provide significant services to the group which benefits the followers
and ensures good outcome for the group . The key services may include
Knowledge, wisdom, organizational skill, Intelligence in respective
domains. These services provided by the leader offer adaptive benefits for
the follower such as defense group against attack, more effective warfare
on rival groups, or simply superior habitat selection for the group. In
exchange, followers offer social prestige to the leader.(Prestigious
salutations such as your highness, chairperson etc).
The qualities which will be helpful in solving adaptive problems are o ften
sought in the leaders. In the context of hunting and warfare,qualities such
as athletic ability, strength, skill in weapon use ,courage are significant
whereas in peacemaking, qualities such as intelligence, good social skills,
oratory skills, and ab ility to unify the group toward a common goal are of
key importance.
Another quality which is often sought among leaders is fairness. Fairness
in this context involves equity as well as equality. In this context, equality
refers to distribution of rewards as a function of individual contribution to
a group, that is, those who have contributed more to the group will get
more rewards and vice versa. Equality on the other hand refers to equal
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138 receive equal rewards irrespective of their contribution. The services -for-
prestige theory predicts which followers will want leaders who adopt each
definition of fairness. Members with above average contributions will
want leaders to value equity as they will gain more resources as a function
of their contribution. On the contrary members with below average will
favor equality since they will be getting equal share despite their low
contribution.
Both leaders and followers benefit from this exchang e hence The service -
for-prestige theory is fundamentally based on reciprocal altruism.
8.4 EVOLUTIONARY THEORY OF SEX DIFFERENCES IN STATUS STRIVING In the earlier unit, we have learned that there are differences in the
obligatory parental investment made by both the genders. For males the
obligatory parental investment in offspring is low as compared to females
and hence the ceiling of reproduction is higher for males than females.
The more polygynous the mating system, the stronger the selection
pressure on the males to become one of the few who would succeed in
reproduction.
Research evidence has shown that women often prefer men with high
status as it ensures increased access to resources, better protection and
support to children and healthcare.(Buss, 1994b; Hill & Hurtado, 1996).
Dominant men often gain increased access to women through intrasexual
domination (Puts, 2010). Dominant men might take the mates of
subordinate men thereby leaving these low -ranking men helpless to
retaliate. This way status and dominance help men to have increased
sexual access and benefits.
8.4.1 Status and Sexual Opportunity :
Let’s now understad if there is any association between status of men and
the sexual oppotunity. Are there any research evidences which proves that
elevated status in men ensures greater sexual opportunity with females?
An extensive research was conducted by Evolutionary anthropologist
Laura Betzig. She gathered systematic data from the first six civilizations
Mesopotamia, Egypt, Aztec Mexico, Incan Per u, imperial India, and
imperial China namely (Betzig, 1993).These civilizations spanned four
continents and roughly 4,000 years, beginning in about 4,000 b.c. All the
six civilizations did show a remarkably consistent pattern. It was found
that Status and rank, afforded men great sexual access to women in each
of the six first recorded human civilizations.
In modern times as well the association between status and sexual
opportunity appears to be strong. In some modern Western cultures
monogamy is legally enforced as it restricts the number of women a man
can marry. In modern society, men with high high status ensures greater
sexual access to a larger number of women (Perusse, 1993). Another
research finding reported that modern men with high income and sta tus munotes.in

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139 Social Behavior And Specific Topics - II found to have more frequent sex and a larger number of children
(Hopcroft, 2006; Weeden, Abrams, Green, & Sabini, 2006). A research
conducted in Austria documented that In the context of universities, high
status male academicians had more children tha n the other employees
which is also in line with the earlier findings. (Fieder et al., 2005).
In sum, we can say that evolutionary logic explains why do men stive for
status more than women as High status in men ensures increased sexual
access to a large n umber of women.
8.4.2 Are men higher in status striving :
Is there any difference in the amount of status striving as a function of
sex? Let's have a look at what researchers have to offer about the same.
A study was conducted by involving six cultures s howed that boys tended
to involve more in rough -and-tumble play, assaults and other aggressive
actions, tried to seek attention, and also issued dominance challenge to
same age peers. Girls on the contrary found to use nurturance and pleasing
sociability m ore than boys (Whiting and Edwards, 1988).
Psychologist Elenor Maccoby (1990), did extensive research to study sex
differences in preschool years. She concluded that rough tough play
characteristics and language seems to be important for boys as it protec ts
an individual's turf whereas for girls conversation is more likely to be a
binding process. She concluded that sex differences in dominance
motivation occurs at a much early age. Those who are high on SDO
(Social Dominance Orientation (SDO) legitimize o ne’s group dominance
over others. Men consistently score higher on SDO than do women.
Findings cross culturally have supported this notion.
8.4.3 Men and Women Express Their Dominance through Different
Actions :
Which acts can be described as the acts of do minance? Is the perception of
dominance acts similar for men and women? Researchers have tried to
explore the sex differences in the perception of dominance acts through
various studies. In one study, researchers collected 100 acts of dominance
(listed pre viously) and asked both men and women to rate each act on two
grounds. One being the social desirability of the act and another was the
extent to which the act was worthwhile in their eyes. It was found that for
women, prosocial dominant acts were rated to be more socially desirable
whereas for men egoistic dominance acts were rated as more socially
desirable. Prosocial dominance acts involved statements such as “Taking
charge of things at the committee meeting,” “Taking a stand on an
important issue withou t waiting to find out what others thought,”
“Soliciting funds for an important cause and egoistic dominance acts
involved statements such as “Managing to get one’s own way,” “Flattering
to get one’s own way,” “Complaining about having to do a favor for
someone,” and “Blaming others when things went wrong (Buss, 1981). munotes.in

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140 Do these sex differences reflect in the actual behaviors of men and
women? Research findings reported that men in reality as well appear to
perform more egoistic dominance acts whereas women a ppear to engage
in prosocial egoistic acts.
Edwin Megargee (1969) conducted an experiment in which he
administered a dominance scale to both men and women and selected
those who scored either high or low. Participants were then put into pairs
in such a way that in each pair there will be one high dominant player and
one low dominant player. He made 4 conditions:
(1) A high -dominant man with a low -dominant man,
(2) A high-dominant woman with a low - dominant woman,
(3) A high-dominant man with a low -domin ant woman, and
(4) A high -dominant woman with a low -dominant man.
Participants were provided with the necessary material and their task was
to act as troubleshooters in a team and repair the boxes given by
unscrewing nuts and bolts and replacing it with d ifferent colors. In the
team they were told they had to choose the leader (providing instructions)
and the follower (act as per the instruction by the leader). It was found that
in same sex pairs, 75 percent of high dominant men and 70 percent of high
domi nant women took the leadership position. Interestingly, when high
dominant men were paired with low dominant women, 90 percent men
took leadership roles. Interestingly when a high dominance woman was
paired with a low dominant man ,only 20 percent women to ok up charge
of leadership positions.
On prima facie, we may believe that women tend to suppress their
dominance or men are compelled to take leadership positions, however
nothing is guaranteed. When the researcher analyzed the recording
between pairs whi le deciding and assuming roles it was found that in 91
percent of the cases women made a final decision and were appointing low
dominant partners to leadership positions which again proves that women
tend to exercise their dominance differently than do men .
Another hypothesis involving sex difference in dominance and status
proposed that men are more likely to use riskier resource strategies when
being observed by others with similar status and not by people who are
either low or high status to them.Elsa Er mer and her colleagues through an
experiment confirmed the assumption that in males status competition gets
more intense while involving men of equal status thereby increasing the
use of riskier strategies. (Ermer, Cosmides, & Tooby, 2008).
8.5 DOMINANCE T HEORY Survival of any species is marked by conflict between those who are
dominant and those who are trying to defeat those who are dominant. In
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141 Social Behavior And Specific Topics - II or subordinate strategies to subvert the access of the dominant individual
to key resources. Dominance theory further proposes that human beings
have evolved a few strategies to reason about social norms involving
dominance hierarchies such as obligation, permission and prohibition. And
these strategies are domain specific.
Cummins supported the theory with a few research findings. Cumin
believed that human reasoning emerges at a much earlier stage as young as
three. Cumin further stated that individuals choose to use different
reasoning strat egies on the basis of whether one is evaluating deontic or
indicative rules. Deontic reasoning refers to reasoning about what an
individual is allowed, obligated and prohibited to do whereas indicative
reasoning involves reasoning about what is true or fal se. It was found that
when individuals evaluate deontic reasoning, they look for rule violations
whereas when they tend to evaluate indicative rules they look for the
evidence which conforms to the rule. For example, if the deontic
reasoning states that” D rinking is permitted only after twenty one years of
age”, individuals will look for instance where the person might be
drinking in spite of being under aged. Whereas in case of Indicative
reasoning if the rule states that all polar bears have white fur, in dividuals
will look for the instances which will conform to the rule (Cummins,
1998).
Dominance theory further states that ranking or status of an individual will
have a strong influence on human reasoning. An experiment conducted by
Mealey, Daood, &
Krag e,(1996) empirically tested this assumption. Participants in this
experiment were shown a few pictures of men along with their social
status (high or low), Character( Trustworthiness, history of cheating) and
biological information. After a week the partic ipants were called to the
laboratory and were asked to recollect which photographs they could
remember. Findings revealed a few patterns. Participants remembered
cheaters more than non -cheaters and this memory was enhanced if the
cheaters were from low sta tus and the same memory bias reduced if
cheaters belonged to high status. Memory biases for cheaters were
stronger for men than women. Another study conducted tested the effect
of status on social reasoning and concluded that there existed a strong link
between these two factors. (Cummins,1998).
8.6 SOCIAL ATTENTION HOLDING THEORY Another theory explaining how the hierarchies are made in species was
put forward by evolutionary psychologist Paul Gilbert (1990,2000a) .This
theory emphasizes on the idea of Res ource Holding Potential (RHP). RHP
put another way is an assessment of one's own strength and weaknesses as
compared to other animals. The dominance hierarchies, as per this theory
emerges from this evaluation. Losers and those who determine that they
are inferior will have low RHP, in contrast Winners and those who
determine before the contest that they are likely to win will have superior
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142 are made an individual might behave in one of three ways such as attack
(High RHP), Flee (Low RHP) or submit.
Another principle that is highlighted in this theory is social attention -
holding potential (SAHP). SAHP refers to the quality and quantity of
attention provided to one individual. According t o this theory hierarchies
emerge from the amount of attention sought by an individual. Those who
receive high quality and quantity of attention, will experience elevation in
status and on the contrary those who are isolated and don't get attention
will be low in status. People often bestow their attention to those who
perform key functions that are valued by bestowers. For example, doctors
who treat the needy.
This theory also emphasizes the emotional components of dominance
(Gilbert (1990, 2000a). The theo ry predicts that increase in rank is
associated with elevations in mood and helpful behavior.
According to SAHP theory, Decrease in status leads to different
consequences for mood and emotion as it results in social anxiety, shame,
rage, envy and depressi on.
8.7 INDICATORS OF DOMINANCE High dominance and status can also be indicated by a variety of verbal and
non-verbal characteristics. In this section we would explore the association
between verbal and non -verbal characteristics with dominance. However,
it is important to note that correlation does not guarantee causation.
1) Verbal and Nonverbal Indicators of Dominance :
Literature has shown that there are significant differences in the physical
posture between dominant and non -dominant people. Dominant
individuals tend to stand at full height, often facing the group, with hands
on hips and an expanded chest whereas less dominant or non -dominant
individuals are exactly the opposite and their body posture is often bent
rather than straight. With respect to t heir verbal and non -verbal behavior,
Dominant individuals generally gaze a lot, look at others while talking, do
not smile much and speak in a loud and a low pitched voice and gesture by
pointing whereas individuals with low dominance speak softly, smile a lot,
listen while other is speaking and generally keep less than those higher in
status.(Argyle 1994, Ketelaar et al., 2012). Literature further suggested
that In men, walking speed is linked with socioeconomic status, linking it
with evolutionary activit ies such as hunting.
2) Size and Dominance :
Ethnographic studies involving different cultures have made frequent
references to a term ‘big man’ which indeed reflects the importance of
physical stature, influence, dominance, power and authority. Research
involving diverse cultures establishes a link between Height and
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143 Social Behavior And Specific Topics - II leaders to be tall and those who are tall tend to show greater interest in
assuming leadership roles than do short people (Murray & Schmitz, 2011).
Experiments were also conducted to test if there is any link between
physical and social stature (Wilson,1968).In one study it was found that
audiences described the man as being tall or not based on the rank
assigned to the indiv idual such as professor, graduate student.
Is there any practical advantage that people get because they are tall over
short people? Research shows that tall men are more likely to get an
advantage in being hired, promoted, and elected (Gillis, 1982)
3) Testosterone and Dominance :
Testosterone (T) is one of the important hormones that contributes to
developing and maintaining “masculine” features in a variety of animals
(Mazur, 2005). The production of Testosterone increases significantly at
puberty whic h brings about the key changes associated with puberty such
as deepening of voice, facial and bodily hair, penis growth, and an
increased interest in sex. Researchers tried to experimentally manipulate
the levels of Testosterone in cows and found that thos e cows tested with T
rose to higher rank and when T was removed they sank to the previous
rank.(Bouissou, 1978).
In the case of humans, studies show that higher levels of Testosterone are
linked with significant antisocial domains and antisocial acts typic ally in
young males.(Mazur, 2005). The mismatch hypothesis further predicts that
if there is a mismatch between the levels of T and the status,(High T &
Low status / Low T & High status) people will experience stress and may
distort their cognitive perform ance (Josephs, Sellers, Newman, & Mehta,
2006). Mazur (2005) Further stated that changes in status also brings about
changes in T. No wonder why winners show elevated in T levels whereas
losers show decrease in T after a competition. This finding is not o nly
limited to athletic competitions but also to the competitions involving
reaction time and chess (Mazur, Booth, & Dabbs, 1992). Elevated T levels
in winners may prepare them for future challenges and may discourage
losers from future confrontations.
Studies have also explored the link between WHR (Waist to Hip ratio) in
men to T and dominance and found that men with high WHR ,with high T
levels are found to have less physical problems.(Singh, 2000).Another
research finding shows that T is positively corr elated with dominance and
not prestige. Most of the research conducted so far in this domain has
explored the relationship between T and social status and dominance in
males and not females. Since the data is limited Further research is needed
to clarify t he links between T and status in women (Grant, 2005).
4) Serotonin and Dominance :
Researchers have also tried to explore the links between serotonin and
status. Range of experiments have been conducted involving both human
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144 with dominance and higher ranks. Evolutionary scientists Michael
McGuire and Michael Raleigh through a series of experiments with
monkeys reported that the amount of serotonin in monkeys varied as a
function of their s ocial status, monkeys being higher in status having
almost twice the level of serotonin than monkeys with lower
status.(McGuire & Troisi,1998). In the case of human beings too it was
found that serotonin indeed is linked with dominance and status as
offic ers' serotonin levels were considerably higher than the regular
members. Interestingly ,a similar pattern was found when researchers
analyzed their own levels of serotonin and found that the serotonin leve;ls
in case of lab director were greater than rese arch assistant.
So far we have reviewed only a few factors that are associated with status
and dominance, however other correlates of dominance and status need to
be further analyzed and studied in order to form a comprehensive theory
of determinants of do minance and status.
8.8 SELF ESTEEM AS A STATUS TRACKING MECHANISM Researchers have explored the concept of self -esteem in context of
prestige, power and status with reference to one’s referent group.
8.8.1 Sociometer theory :
Why do human beings form diff erent groups and choose to stay in the
group? Why is group membership so important for an individual? Why do
people look for or strive for acceptance by group? Evolutionary logic
explains that human beings started living in groups as it offered key
resourc es, protection which was critical to one's survival and reproduction.
Group acceptance is important to enjoy these benefits and failure to gain
acceptance would lead to isolation and loss of protection hence group
membership and acceptance has been long fa vored by human beings. By
this logic, as group acceptance is key to survival and reproduction, we
must have evolved some mechanisms through which we may track the
level of one’s acceptance in society.
Sociometer theory states that Self Esteem is one such indicator which
helps people measure one's acceptance in groups. As put by Barkow
(1989) self -esteem tracks dimensions of prestige, power, and status within
one’s referent group. As per the arguments of sociometer theory self -
esteem reflects other people’ s evaluation about self. An increase in self -
esteem reflects an increase in the degree to which one is socially accepted
by others and vice versa.(Baumeister & Leary, 1995; Leary, Haupt,
Strausser, & Chokel, 1998) A range of studies have empirically tested the
arguments and have gained support for the theory.
According to the expanded Sociometer theory, self -esteem also serves a
few evolutionary functions. First, Self -esteem serves as a motivator to
design one's actions in such a way that gains respect fr om others, as it is
linked with status and reputation. Secondly, accurate evaluation of self -munotes.in

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145 Social Behavior And Specific Topics - II esteem helps an individual to understand one's position in social hierarchy
and then to manage their strategies (challenge or submit) accordingly.
Third function o f self -esteem helps an individual in gauging one’s
desirability in the mating domain.
In an interesting study, The researchers analyzed self -evaluation of both
male and female participants on the dimension of self -desirability as a
marriage partner. These evaluations were taken after exposing them to the
photographs of same sex other who were either dominant or less dominant
and physically attractive or less attractive. Findings of the experiment
revealed that physical attractiveness of same sex other cons iderably
impacted women participant’s self -evaluation but not the evaluations of
male participants. On the contrary, dominance of same sex other had
considerable impact on the self -evaluation of male participants but not of
female participants.(Gutierres, Kenrick, & Partch, 1994).However more
research is needed to form a comprehensive theory.
8.9 STRATEGIES OF SUBMISSIVENESS Not all people stand at the high end of dominance or not all people stand
high in their status. Not all people in a group situation as sume the
leadership role. Much research has focused upon exploring the domain of
high status and dominance but what about the other end of the continuum?
In this section we would explore the domain of being submissive and
strategies used by those who are s ubmissive in nature.
8.9.1 Sex Differences in Submissive Strategies :
Though this domain has received less research attention, evidences
suggest that there is a difference as a function of sex in the tactics and
strategies employed by men and women while ne gotiating with powerful
men. In this section we shall discuss some of the commonly used
strategies by both the sexes.
1) Deceiving Down :
Consider two situations: A man who is doing a job that does not fully take
advantage of his talent or a woman who belie ves that she is more
intelligent than her husband.(Hartung,1987).
By evolutionary logic this may pose an adaptive problem as the superior
might fire the employee for insubordination and in case of the other
example the spouse might seek someone with whom h e is more
comfortable. Adaptive solution to this problem comes in the form of a
strategy of deceiving. Deceiving down should not be misunderstood as
playing dumb. It refers to actual reduction in the self -confidence to act in a
subordinate or submissive ma nner. Evolutionary literature shows that
when such situations existed it was always adaptive to act as submissive
thereby being non -threatening and avoiding further wrath and conflict.
However further research is needed to explore consequences of deceiving
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146 2) The Downfall of “Tall Poppies” :
Have you seen people taking delight in someone else's misfortune? Do
you think that having a great status attracts envious notice or hostility from
others? As defined by Oxford English Dict ionary “Tall poppy” refers to
“an especially well -paid, privileged, or distinguished person” (Simpson &
Weiner, 1989) Another definition comes from The Australian National
Dictionary Tall poppy refers to “a person who is conspicuously
successful” and “one whose distinction, rank, or wealth attracts envious
notice or hostility” (Ramson, 1988).A rough translation of English would
be having pleasure in someone else's misfortune.
Feather et al conducted an experiment involving people from Japan and
Australia an d analyzed people's reaction towards the fall of tall poppies.
For example, an academic Superstar might plunge in performance on a
critical final exam. Researchers asked participants to read such scenarios
which varied on certain features such as whether t he fall was small or
large, cause of fall to be the mistake by a poppy and whether the person's
initial success was deserved. Tall poppy scale served as one of a
dependent measure and it included statements such as “It’s good to see
very successful people fail occasionally,” “Very successful people often
get too big for their boots” etc. Findings revealed that people reported
more happiness by the fall of tall poppies when the high status of the
person was made salient. Participants' reaction varied as a fu nction of their
belief about if the tall poppy deserves the success. Lastly, Envy was
commonly experienced emotion particularly if the domain of success is
what people valued. Self -esteem too played a role as participants with low
self-esteem had more form ed more favorable reactions to the fall of tall
poppies. It was also found that cultural differences in the pattern of
reaction was found as Japanese participants reacted more favorably to the
fall of tall poppies than the Australian participants. The find ings suggest
that facilitating the fall of people with greater status and taking delight in
their fall are used as submissive strategies. One's success is always taken
as relative to others hence one way to achieve the same is by self
enhancement and anoth er is by promoting the downfall of others,
interestingly people tend to use both.
Further researchers tried to explore under what conditions people might
use submissive strategies. Studies suggest that social comparison plays a
key role in activating subm issive strategies. (Buunk & Brenninkmeyer,
2000). In addition to the strategies discussed above human beings have
long used tactics such as including creating greater distance from the
dominant individual, hiding, escaping, remaining passive, signaling def eat,
eliciting help from others, and signaling agreeable and cooperative
proclivities (Fournier, Moskowitz, & Zuroff, 2002; Gilbert, 2000a,
2000b). Human beings may also use conformity to avoid being
stigmatized and ostracized (Kurzban & Leary, 2001; Will iams, Cheung, &
Choi, 2000).
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147 Social Behavior And Specific Topics - II 8.10 COGNITIVE DEVELOPMENT We often study psychological mechanisms in the context of information
processing devices which are made specific to solve adaptive problems.
As adaptive problems are typically social in nature, Cogni tive psychology
must consider the ways in which human beings understand and process
information while dealing with other people. Literature helps us
understand that some core assumptions of cognitive psychology are
challenged by evolutionary psychology (Co smides & Tooby, 1994).
Cognitive Psychologists assume that cognitive architecture is a general
purpose mechanism and content free, whereas evolutionary psychologists
take an opposite stand and state that the mind involves specialized
mechanisms for solvin g specific adaptive problems. Secondly, for the sake
of ease of presentation and experimental manipulability, cognitive
experimental psychology mainly involves material like triangles, shapes or
a few circles, nonsense syllables as opposed to kin, enemies, mates.
According to evolutionary perspective, assuming mind as a general
mechanism is problematic as successful adaptive qualities will be different
for one domain than the other.
Cognitive Psychology further believes that information -processing
mechani sms can be studied without considering the adaptive problems
they were designed to solve, a view typically known as functional
agnosticism. On the contrary evolutionary psychology states that, it is
impossible to understand how human beings act, processes take decisions
without understanding the functions of cognitive mechanisms performing
these activities. Replacing the core assumptions, evolutionary psychology
permits the integration with other life sciences (Tooby & Cosmides,
1992).
1) Attention and Memo ry:
As indicated by researchers, Attention and Memory are valuable yet
limited resources, hence are highly selective (Klein, Cosmides, Tooby, &
Chance, 2002).
It has been indicated that human memory and attention is extremely
sensitive to store and retriev e information highly specific to solve adaptive
problems (Klein, Cosmides, Tooby, & Chance, 2002). One of the
researchers made use of eye -tracking technology and found that women
were more likely and strongly responded with attentional bias toward
viewin g infants than men (Cardenas, Harris, & Becker, 2013), which
proves that evolutionary relevance influences attention (Jackson &
Calvillo, 2012). Evolutionary psychologists assumed the memory systems
to be somewhat domain specific for survival and reprodu ction. The
researchers used a standard memory experiment paradigm and made
participants participate in a surprise recall test and it was found that those
words rated relevant for survival were remembered better than words rated
for relevance in a variety o f control scenario conditions.(Nairne &
Pandeirada, 2008, p.242; see also Nairne et al., 2012). munotes.in

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148 2) Problem solving, Heuristics ,Judgment under uncertainty :
Cognitive Researchers have indicated that Human beings are more likely
to make errors when solving problems and making decisions under
conditions of uncertainty (Nisbett & Ross, 1980; Tversky & Kahneman,
1974).It further shows that human beings are predisposed to certain type
of biases and errors; Base rate, Conjunction fallacy to name a few. Base
rate fallacy indicates that humans are more likely to ignore actual
statistical information when presented with compelling individuating
information. Evolutionary perspective poses a challenge to specific
cognitive view that problem solving capacities of huma n beings are
subjected to certain errors and biases (Cummins & Allen, 1998).As per the
notion of evolutionary psychology, designing experiments which are more
close to the setting in which human beings learn to solve the adaptive
problem would paint a diff erent picture of cognitive capacities of humans
under the uncertain situations. However it is not implied that the human
mind is completely free from biases, rather certain biases are adaptive in
nature that solve the problem of survival.
3) Language :
As stated by Pinker ,“Simply by making noises with our mouths, we can
reliably cause precise new combinations of ideas to arise in each other’s
minds”.The two primary questions which are discussed in evolutionary
context are as follows: Is language an adaptati on and if yes what adaptive
problems did it solve?
Noam Chomsky and Stephen Jay Gould have argued that language is a by -
product of the tremendous growth of the human brain rather than an
adaptation.As per these researchers many functions emerged as a side
effect of brain growth.However they eased their positions and allowed the
possibility that human language could have been guided by particular
selective pressures which are unique to our evolutionary past, or a
consequence (by -product) of other kinds of ne ural organization” (Hauser,
Chomsky, & Fitch, 2002).
On the contrary evolutionary psychologist Steven Pinker strongly argues
that language is an adaptation. According to him language involves
universal elements found across all the languages such as verb,
proposition, temporal distribution of events ( past ,present, future). He
further stated that children usually by the age of three, without much
formal training masters the complex structure of language. Language is
also linked to specific brain areas and any damage to these areas results in
certain impairments. All these support the notion that language is an
adaptation. Pinker further argued that language is evolved to facilitate
communication which necessarily involves the exchange of information
between individuals which is used to convey a variety of information such
as possible threat, coordinating for coalition in context of war or hunt,
coordinating construction of shelter etc. (Pinker, 1994).Though there are a
few competing theories, the dominant th eory of information
communication cannot be dismissed (Pinker & Jackendoff, 2005). munotes.in

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149 Social Behavior And Specific Topics - II 4) Human Intelligence :
As put by Leonard & Robertson,1994, “Although the human brain makes
up only 2 to 3 percent of the average human’s body weight, it consumes
roughly 20 to 25 percent of the body’s calories”. Human beings have a
larger brain relative to body size. Human brain houses unprecedented
capacities for abstract thinking, reasoning, learning, and scenario -building.
There has been a great debate as to why human bein gs evolved these
cognitive capacities. According to the ecological dominance/social
competition (EDSC) hypothesis, human ancestors could defeat many of
the traditional “hostile forces of nature” such as food shortages, warfare,
pestilence, and extreme wea ther. that previously impeded survival.
According to the EDSC hypothesis, human dominance over the ecology
paved the way for a new set of selective forces, namely competition from
other humans .Living in a large multifaceted social group demands certain
adaptive problems to be solved such as forming coalitions, punishing
cheaters, detecting deception, and negotiating complex and changing
social hierarchies.
8.11 MODULARITY OF MIND AND INNATENESS ISSUES The idea of modularity of mind emerged somewhat uncle arly in the
literature of psychology in 1980’s following Fodor’s landmark book The
Modularity of Mind (1983). Fodor has focused on nine characteristics or
features of modularity and they are as follows: Modular systems are
localized, Subject to characteris tic breakdowns, mandatory, fast, shallow,
Ontogenetically determined, domain specific, inaccessible, subjected to
breakdown, informationally encapsulated. The Moderate modularity
hypothesis has two parts. The first part states that certain input systems
involved in language and perception are modular whereas systems
involved in belief fixation and modular reasoning are not modular. Input
systems can be thought of as a computational mechanism which “presents
the world to thought” by processing the outputs of sensory transducers. A
sensory transducer can be understood as a device which converts the
energy impinging on the body’s sensory surfaces, into a computationally
usable form.It does so without adding or subtracting information for
example retina or coch lea. The idea of modularity of input systems has
been criticized and opposed by many psychologists (Churchland, 1988;
Arbib, 1987; Marslen -Wilson & Tyler, 1987; McCauley & Henrich,
2006). Fodor in his claim further states that certain systems cannot be
understood as informationally encapsulated hence central systems are not
modular.
Evolutionary psychology argues that the human mind involves a set of
cognitive adaptations which are mainly designed by the natural selection
process. From an Evolutionary persp ective as put by, Tooby and Cosmides
(1992) the better analogy for the human mind is not that of a general all -
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150 Evolutionary Psychology states that the mind is not a logic device but a
specialized mechanism e volved to deal with specific or certain forms of
adaptive problem. For example, to understand how fear responses are
learned in monkeys, Mineka et al, conducted a series of experiments on
rhesus monkeys. It was observed that those rhesus monkeys raised in
captivity showed no evidence of fear to snakes however monkeys captured
in wiled did show the evidence of fear and panic even to a toy or a rubber
snake. Further it was found that naive lab raised monkeys developed the
fear of snakes following exposure to motion films in which wild captive
monkeys were shown reacting fearfully to snakes. Studies by Mundkur
(1978) have also shown the universal tendency among human beings to
attribute symbolic significance to certain animal species. Cooke (1996)
further argue d that this phenomenon is known as evolution of interest
which makes certain stimuli more intrinsically interesting to us than
others. He showed that even if the countries have an environment that is
free from snakes, presence of serpents is found in art and motifs and
sculptures. From this it is evident that fear learning is an evolved
psychological mechanism. Cosmides and tooby further studied people's
ability to reason logically using a Wason Selection task in the context of
social situations. It was ob served that participants performed better in the
social context as food ,drink, cheat detection. Tooby and Cosmides argued
that we have evolved a special propensities for dealing with problems
involving social contract by activating a cheat detection mecha nism.
Evolutionary account of human cognition focuses on innate psychological
mechanisms. It is important to understand what purpose various cognitive
capacities serve or for what purpose different cognitive capacities have
evolved? Mind can be seen as a u nit consisting of different independent
modules to deal with various environmental pressures.
As put by Steven Pinker, The human mind is not a general purpose
computer but a collection of instincts adapted for solving evolutionary
significant problems.Evo lution refers to change over time. Darwin argued
for the notion “struggle for existence,” in which favorable variations tend
to be preserved and unfavorable ones tend to die out.
Common Misunderstandings in the field of evolutionary Psychology are
as foll ows :
1. Human Behavior Is Genetically Determined Evolutionary theory
represents a view that focuses on both evolved adaptations and
environmental input.
2. If it is evolutionary, we can't change it evolutionary theory does not
imply that human behavior is impervious to change.
3. Current Mechanisms Are Optimally Designed.
8.12 SUMMARY In this unit we began by discussing how status hierarchies are formed in
non-human species. Then we discussed what functions do these munotes.in

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151 Social Behavior And Specific Topics - II hierarchies serve and how they help to solve adaptive problems of survival
and reproduction. In the later section, we tried exploring the theoretical
perspective underlying dominance, status and prestige. We discussed the
following question: Why do people strive for prestige? We then discuss ed
dominance hierarchy theory which argued that some individuals will have
greater access to the key resources critical for survival and reproduction.
Dominance and Social Holding potential theory was also discussed. The
other end of the Dominance continuu m namely submissiveness and the
sex differences in the strategies used by male and female also explored.
We concluded our chapter with the discussion of cognitive development
and modularity of mind in brief.
8.13 QUESTIONS A) Write long answers:
a) Discuss how hierarchies are formed and explain dominance theory in
detail.
b) Elaborate evolutionary theory of sex differences in status and prestige
in detail.
c) Write a note on submissiveness strategies used by men and women.
B) Write short notes:
a) Indicator s of Dominance
b) Cognitive Development
c) Dominance and Status in Non Human Species
d) Self Esteem as status tracking mechanism
8.14 REFERENCES  Barkow, J. H., Cosmides, L., Tooby, J. (1992). The adapted mind.
Oxford University Press.
 Buss, D. (2011). Evol utionary Psychology: A New Science of Mind.
Pearson Education.
 Buss, D. (2005). The Handbook of Evolutionary Psychology. John
Wiley & Sons, Inc.
 Buss, David M. Evolutionary psychology : the new science of the
mind/David M. Buss, The University of Texas at Austin. Fifth edition.
 Fodor, J. A. (1983). The modularity of mind. Cambridge, MA: MIT
Press
 Prinz, Jesse. (2006). Is the mind really modular?. Contemporary
Debates in Cognitive Science.
*****
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