Biological influences on criminal behaviour: how good is the evidence?

Available studies have their limitations

The perception that crime, especially violent crime, has become one of the most serious problems facing society has led to determined efforts by many researchers to find the causes of criminal behaviour. Researchers have focused on biological causes, believing that a biological basis of criminality exists and that an understanding of the biology will be useful in predicting which people are predisposed to become criminals. In the 1960s it was proposed that males with an extra Y chromosome were predisposed to violent criminal behaviour; later work found no support for this hypothesis.1 Recently, two approaches, one genetic, the other biochemical, have received widespread publicity. I would argue that currently neither approach provides convincing evidence that criminal behaviour can be understood in terms of genetics or biochemistry.

Before these two approaches are discussed, the many family, twin, and adoption studies that have concluded that a biological basis exists for antisocial behaviour should be noted.2 3 4 At least two recent reviews, however, have suggested that the support for these conclusions, especially those concerned with violent …