Genetic variance is attenuated at higher levels of religiosity in adolescence, consistent with the social control hypothesis. That is, the environment is sufficiently influential (i.e. there is likely to be pressure to not drink) that it over-rides any genetic predispositions. Some additional evidence for the social control hypothesis is found in the increase in shared environmental variance in more religious adolescents, suggesting that people who are religious are closer to their families, and are more influenced by them. Previous studies have demonstrated that religiosity in adolescents is almost entirely due to shared environmental effects (Boomsma et al. 1999; Koenig et al. 2008), and it is possible that this is because adolescents tend to follow their parents in religious matters. This increased likelihood to be religious if your parents are, and the control religious parents potentially exert over their adolescent offspring, would influence the siblings being raised in the same family similarly, and manifest itself as a shared environmental effect on alcohol related behavior. This is providing that there is variation among religious households in their attitudes towards drinking. For example,
