The Single Factor Fallacy

In one line

Every single-factor theory of crime has failed for the same two reasons: the factor is absent in many offenders, and it is present in enormous numbers of people who never offend.

In the wording a student can write in an exam: a single factor explanation of crime is one that identifies a single condition as the cause of criminal behaviour; each such theory fails the test of necessity, because offenders exist in whom the factor is absent, and the test of sufficiency, because the factor is present in very large numbers of non-offenders.

The test to apply

Learn this and every single-factor theory can be dismantled in two sentences.

Is the factor necessary? If offending occurs without it, it cannot be the cause.

Is the factor sufficient? If the factor occurs without offending, it cannot be the cause by itself.

A cause in the strict sense should be both. No candidate in the history of criminology has been either.

The candidates, and how each fails

Heredity and physical type. Lombroso's born criminal. Not necessary, because most offenders have none of the stigmata. Not sufficient, because Goring found the features distributed as widely outside prisons as within them.

Low intelligence. Advanced by Goring and by others in the early twentieth century, with prison populations reported to test poorly. Not necessary: fraud, forgery and corruption require ability. Not sufficient: most people who test poorly never offend. And the finding was largely an artefact of who gets caught, since a person of low ability is more easily detected and less able to defend himself.

Poverty. Not necessary, because the offences of Module III are committed by the prosperous. Not sufficient, because most poor people do not offend, and some of the poorest regions record the lowest rates, which Guerry found in the 1830s.

The broken home. Not necessary: many offenders come from intact families. Not sufficient: most children of separated or bereaved parents do not offend. Later work found that it is conflict and supervision, not the structure of the household, that matters.

Mental illness. Not necessary, since the overwhelming majority of offenders have no diagnosable disorder. Not sufficient, since the overwhelming majority of people with mental illness never offend and are far more likely to be victims.

Bad company. Closer than most, and it is the basis of Sutherland's theory. Still not sufficient on its own, because it does not explain who becomes the company, and not necessary for offences committed alone.

Mass media. Neither. The effect that research finds is small, short-lived and conditional, and the vast majority of those exposed do not offend. Dealt with in its own chapter.