found that environments across a number of different domains can play important roles in moderating the importance of genetic effects. Initially we found that a number of different socioregional factors moderated the relative importance of genetic and environmental effects. Genetic influences on frequency of alcohol use in late adolescence (ages 16–18) were stronger in urban settings, neighborhoods with greater regional alcohol sales, those with more migration in and out (which we believe may represent greater anonymity and less community monitoring), and those which had a greater percentage of slightly older adolescents (likely providing more alcohol availability and diversity of selection of role models and activities) (Dick et al., 2001; Rose et al., 2001). Similar socioregional effects were observed earlier in adolescence on behavior problems in girls at age 14 (Dick, Bernard, et al., 2009).
