Adult antisocial behavior (AAB), which is broadly defined as a ‘pervasive pattern of disregard for and violation of the rights of others',1 is relatively common and is associated with adverse consequences for both individuals and societies. According to prevalence estimates from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions, 3.63% (95% confidence interval=3.34–3.92) of adult Americans qualify for an antisocial personality disorder (ASPD) diagnosis, and men are affected at a greater rate than women.2 Findings from the all-male Vietnam Era Twin Registry indicate that ASPD is highly heritable, with genetic factors accounting for 69% of the variation in diagnoses.3 Twin and adoption studies further indicate that dimensional measures of AAB are moderately heritable, with genetic factors accounting for ~40% of the variation in these behaviors.4, 5, 6 These figures are similar to the results from a meta-analysis of 51 twin and adoption studies from child, adolescent and adult samples, which found that additive genetic influences accounted for 32% of the variance in antisocial behavior.7
