The purpose of this study was to examine sex differences in the genetic, shared environmental and non-shared environmental influences on antisocial behavior in childhood and adulthood. We found that the genetic or shared environmental factors influencing antisocial behavior were different for males and females in childhood (i.e., a qualitative sex difference) but not adulthood. Further, genetic and environmental influences accounted for proportionally the same amount of variance in antisocial behavior for males and females both in childhood and adulthood (i.e., no quantitative sex difference). The stability of antisocial behavior from childhood to adulthood was slightly greater for males than females, and genetic factors accounted for the majority of the covariation between CD and AAB for both sexes. However, familial factors accounted for more of the stability of antisocial behavior for males than females. Finally, the genetic influences on AAB overlapped completely with the genetic influences on CD for both sexes.
