Genetic influences on antisocial behavior increased and shared environmental influences decreased from childhood to adulthood for both males and females, consistent with the findings of Lyons et al. (1995) and Jacobson et al., (2002). However, whereas Jacobson et al. (2002) found that the increase in heritability across development was attributable to new genetic influences emerging in adolescence and adulthood, the results from both our study and Lyons et al. suggested that the genetic influences on adult antisocial behavior completely overlap with the genetic influences on childhood antisocial behavior, and the magnitude of genetic influences on antisocial behavior simply increases with age. Jacobson et al.’s intriguing finding of unique genetic influences on antisocial behavior emerging in adulthood still awaits replication. The increasing influence of genes and decreasing influence of shared environment across development demonstrated across studies could simply reflect an adult’s greater control over their environment relative to a child, and therefore may be the outcome of an active genotype-environment correlation.
