A study of the moderating effects of socioeconomic status (SES) on genetic and environmental influences on alcohol use has found that genetic effects on amount of alcohol use are greater in
socioeconomically disadvantaged environments. Hamdi, a doctoral student at the University of Minnesota, and colleagues used data from the MacArthur Foundation Survey of Midlife Development in the United States, initially conducted during 1995-1996 to examine physical health, psychological wellbeing, and social responsibility throughout midlife, with a reassessment of participants during 2004-2006.
The study examined a sample of 672 complete twin pairs, ages 25-74, comprised of 350 monozygotic (MZ) pairs and 322 dizygotic (DZ) pairs. Phone interviews and self-administered questionnaires were used to examine whether SES, measured by household income and educational attainment, moderates genetic and environmental influences on three indices of alcohol use: amount used, frequency of use, and problem use.
The study found that found significant moderation for the amount of alcohol used. Specifically, genetic effects were greater in low-SES conditions, shared environmental effects (i.e., environmental effects that enhance the similarity of twins from the same families) tended to increase in high-SES conditions, and nonshared environmental effects (i.e., environmental effects that distinguish twins) tended to decrease with SES. This pattern of results was found for both income and education, and it largely replicated at a second wave of assessment spaced 9 years after the first. There was virtually no evidence of moderation for either frequency of alcohol use or alcohol problems.
The findings indicate that genetic and environmental influences on drinking amount vary as a function of the broader SES context, whereas the etiologies of other drinking phenomena are less affected by this context. Efforts to find the causes underlying the amount of alcohol used are likely to be more successfu.l
Source: Socioeconomic Status Moderates Genetic and Environmental Effects on the Amount of Alcohol Use. Hamdi NR, Krueger RF, South SC. Alcohol Clin Exp Res. 2015 Mar 17.