Brain Abnormalities and Crime

Despite the large body of knowledge accumulated by neuroimaging research in the last few decades associating criminal behavior to various neurobiological risk factors, the most well-known theories of criminology remained focused on the use of social and environmental variables to explain criminal and antisocial tendencies. The lack of inclusion of a neurobiological aspect in these theories prevents an in-depth understanding of the complicated biosocial mechanisms underlying criminal behavior, specifically regarding the role that brain abnormalities play in predisposing individuals to criminal and/or violent behavior. This gap in theories can be viewed as problematic especially since several reports have confirmed high rates of brain abnormalities among death row [Page 106]inmates, forensic psychiatric inpatients, and other individuals with a history of violence.

The phrase brain abnormalities is often employed, as an umbrella term, to describe congenital or acquired anatomical or functional alterations in the brain. Brain abnormalities have long been associated with psychiatric disorders, such as antisocial personality disorder (APD) and psychopathy, of which criminal behavior is a prominent feature. Several hypotheses and models have been proposed based largely on empirical evidence from brain imaging literature.

This entry reviews a key hypothesis, the frontal lobe dysfunction hypothesis, which has received a great deal of attention in the past few decades with regard to the neural bases of antisocial, criminal behavior. Specifically, the theory as well as the supporting empirical evidence from lesion, neuropsychological, and neuroimaging findings of structural and functional brain abnormalities in the frontal lobe of criminal offenders and antisocial individuals is discussed. This is followed by a discussion on other models of brain abnormalities and crime, specifically the somatic marker hypothesis and the violent inhibition mechanism, which focuses on brain deficits underlying poor decision making and moral reasoning aspects of criminal offending. This entry concludes with an assessment of the hypothesized link between brain abnormalities and crime, and with a discussion of implications for future studies.