Socioeconomic Status and Adolescent Alcohol Involvement: Evidence for a Gene-Environment Interaction

Adolescent alcohol use patterns stem from both genetic and environmental influences. In addition to these factors contributing additively to risk for use, genetic and environmental factors interact with each other to inhibit... [ view full abstract ]

Adolescent alcohol use patterns stem from both genetic and environmental influences. In addition to these factors contributing additively to risk for use, genetic and environmental factors interact with each other to inhibit or exacerbate risk (Young-Wolff et al., 2011). Socioeconomic status (SES) is one environmental factor that might interact with genetic risk for alcohol use. Two theories exist for understanding how SES might interact with genetic risk: 1) the social control model (Shanahan & Hofer, 2005) and 2) the diathesis stress model (South et al., 2015). Evidence for these two competing theories is complicated by the fact that an agreed upon definition of SES has not been reached, and many studies conceptualize the term using only social status or financial status indicators. The current study examined indicators of both family social status and financial resources as potential moderators of genetic and environmental influences on alcohol involvement among adolescents using data from the 1962 National Merit Twin Study. 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. Results provided evidence for moderation of genetic and environmental influences on alcohol involvement by family income.  For twins with the lowest levels of family income, genetic influences accounted for 50% of the variance in alcohol involvement, compared to just 2% of the variance among those at the highest level of income. Shared environmental influences accounted for 67% of the variation among twins at the highest levels of family income compared to 26% among twins at the lowest level of income. Despite a lack of significance, analyses did show that genetic and shared environmental influences varied across average parental education levels, particularly for females. These findings suggest etiological influences on alcohol involvement vary as a function of an adolescent’s socioeconomic status. Implications and limitations are discussed