Biology and Crime

Abstract

Research into biological factors in the etiology of crime has long been out of favor in the United States. Yet all human behavior is partly the result of physiological causes, and it is a reasonable hypothesis that both nature and nurture influence antisocial behavior. Recent research has tested that hypothesis and results seem to confirm it. A growing body of research has consistently found that identical twins are likelier both to have criminal records than are fraternal twins. Adoption studies have found that, controlling for the criminality of the adoptive parents, adopted children whose biological parents had criminal records are likelier themselves to have criminal records than are adopted children of noncriminal biological parents. Psychophysiological studies of the autonomic nervous system, primarily using skin conductance measures, suggest that repetitively antisocial people tend to have low arousal levels and slow skin conductance recovery. These factors may play a role in learning to avoid antisocial behavior. The consensus of neurophysiological research findings is that criminals' electroencephalograms (EEG) are more often abnormal than are those of noncriminals and that there is some slowing of EEG frequency in habitual offenders. Research into the relations among epilepsy, EEG, and aggression has produced no clear consensus. There are similarities in the skin conductance and EEG research: both slow alpha frequencies and diminished skin conductance responsiveness are associated with low arousal states. There is no question that biochemical and pharmacological factors contribute to antisocial behavior, but the extent of their contribution, relative to social and other environmental factors, is unclear. Drugs and other endogenous materials are not intrinsically criminogenic but elicit antisocial behavior under particular cultural, social, and personal circumstances. Taken together, research into the relation between biology and crime leaves no doubt that social and biological variables, and their interactions, are important to our understanding of the origins of antisocial behavior.