Objective: Adolescence is an optimal developmental stage for examining the interplay of environmental factors and the genetic risk for alcohol involvement. The current study aimed to examine how socioeconomic status might interact with genetic risk for alcohol involvement among adolescents.
Method: A total of 839 same-sex adolescent twin pairs (509 monozygotic and 330 dizygotic) from the 1962 National Merit Twin Study completed a questionnaire containing items assessing alcohol involvement. Twins were approximately 17 years old at the time of participation. Parents provided reports of family income and educational attainment. Models were fit examining parental education and family income as moderators of genetic and environmental influences on alcohol use.
Results: There was evidence for moderation of genetic and environmental influences on alcohol involvement by family income. For twins with the lowest levels of family income, genetic and shared environmental influences accounted for 50% and 26% of the variance in alcohol involvement, respectively, compared with 2% and 67% of the variance among those at the highest level of income.
Conclusions: These findings suggest that etiological influences on alcohol involvement vary as a function of an adolescent's socioeconomic status.