The aim of the current study was to test the hypothesis that religiosity is a protective factor for problem alcohol use in adolescents and young adults, and to examine the extent to which genetic effects are contextually dependent on religiosity. Based on previous findings we expect genetic influences to be attenuated in participants who are more religious, as predicted by the social control model. Furthermore, studies have shown that shared environmental variance is greater for religiosity in adolescence than in adulthood, suggesting that there is more social control in adolescence (Boomsma et al. 1999; Button et al. under review; Koenig et al. 2005). Therefore, we might expect religiosity to influence alcohol problems differently in adolescents compared with adults. Given previous evidence of greater social control of religiosity in adolescence than in adulthood, we hypothesize that religiosity may attenuate the heritability of alcohol problems more in adolescence than in adulthood. This is the first study, to our knowledge, to examine this potential age difference for alcohol problems.
