Our findings of lower mean levels of problem alcohol use at higher levels of religiosity further add to the literature reporting a protective effect of religiosity against drinking alcohol. A number of reasons for this decrease are possible. Certain religions may forbid, or at least restrict the use of alcohol, reducing its use in religious followers. People who subscribe to religious beliefs may also be naturally less inclined to drink alcohol and therefore develop problems with alcohol. Also, people who hold religion as important may be more likely to associate with other religious individuals, and less with individuals who promote alcohol consumption. In contrast to the study by Koopmans et al. (1999), we found an attenuated variance associated with higher levels of religiosity for alcohol problem scores in adolescence and young adulthood. This lower variance is consistent with the social control theory in which religiosity restricts behavior and subsequently the total phenotypic variance of alcohol problems.
