It is striking that all of the significant effects that we found were limited to girls. Similar sex differences were reported previously in a study of gene–environment interaction involving socioeconomic status and adolescent antisocial behavior, in which neighborhood conditions had a greater moderating effect on genetic and environmental influences on female antisocial behavior than male antisocial behavior at ages 16 to 17 (Tuvblad et al., 2006). But in addition to the moderation effects found only in females, we also found that main effects of each of the neighborhood variables on alcohol use at age 14 were limited to girls. Interestingly, in previous analyses of age 14 drinking in this sample, we found evidence that common environmental influences on alcohol use at this age showed some sex-specific effects (Rose et al., 2001a). Girls are also somewhat, albeit not significantly so, more likely to report drinking than are boys at this age, perhaps reflecting the earlier developmental maturation of girls, compared to age-matched boys, and its accompanying association with older peers and boyfriends. There is a growing body of evidence suggesting that
