IQ in high school as a predictor of midlife alcohol drinking patterns

The aim of the present study was to assess the relationship between adolescent IQ and midlife alcohol use and to explore possible mediators of this relationship.

Study data were from 6300 men and women who participated in the Wisconsin Longitudinal Study of high-school students graduating in 1957. IQ scores were collected during the participants' junior year of high school. In 2004, participants reported the number of alcoholic beverages consumed (past 30 days) and the number of binge-drinking episodes. A multinomial logistic regression was conducted to determine the relationship between adolescent IQ and future drinking pattern (abstainer, moderate drinker, or heavy drinker), and Poisson regression was used to examine the number of binge-drinking episodes. Two mediators-income and education-were also explored.

Every one-point increase in IQ score was associated with a 1.6% increase in the likelihood of reporting moderate or heavy drinking as compared to abstinence. Those with higher IQ scores also had significantly fewer binge-drinking episodes. Household income, but not education, partially mediated the relationship between IQ and drinking pattern.

The present study suggests that higher adolescent IQ may predict a higher likelihood of moderate or heavy drinking in midlife, but fewer binge-drinking episodes. The study also suggests that this relationship is mediated by other psychosocial factors, specifically income, prompting future exploration of mediators in subsequent studies.