Crime Causation: Biological Theories

Recent molecular genetics studies report that a gene related to the serotonin system may be associated with increased risk for the cooccurrence of violence and alcoholism. These efforts have been fueled by the robust finding that alcoholism and violence, in humans and nonhuman primates, may be related to serotonergic dysregulation (Virkkunen et al., 1989; Higley et al., 1992). In a reanalysis of data from the Swedish Adoption Study, Carey (1993) noted that paternal violence is linked to alcoholism in adopted-away males.

The present authors are currently investigating the possible genetic link between violence and alcoholism (Tehrani and Mednick, forthcoming). Within the context of the Danish Adoption Cohort, we found that alcoholic biological parents were twice as likely to have a violent adopted-away son than nonalcoholic parents. In contrast, the risk for property offenses in adopted-away sons of biological parents with alcohol problems was not significantly elevated. The significant genetic effect was specific to violent offenders. Moreover, violent offending, but not property offending, among the biological parents was associated with severe alcohol-related problems in the adopted-away males. These findings from our adoption cohort are in agreement with data from the Swedish adoption study, and support the overall interpretations from recent molecular genetic studies.

Genetic factors, as determined by a biological background positive for criminality or mental illness, may represent one pathway through which the risk for a certain negative outcome is conferred. Our research group has also explored the role of prenatal factors in the development of criminal behavior.