The Dopamine Transporter Gene, a Spectrum of Most Common Risky Behaviors, and the Life Course

Guang Guo, University of North Carolina at Chapel Hill

This study tests the specific hypothesis that the 9R9R genotype in the DAT1 gene exerts a general protective effect against a spectrum of risky behaviors relative to the 10R9R and 10R10R genotypes, drawing on three-time repeated measures of risky behaviors in adolescence and young adulthood on about 822 non-Hispanic white males from the Add Health study. Our data have established two empirical findings. The first is a protective main effect in the DAT1 gene against risky behaviors. The second is that the protective effect varies over age, with the effect prominent at ages when a behavior is illegal and the effect largely vanished at ages when the behavior becomes legal or more socially tolerated. Both the protective main effect and the gene-lifecourse interaction effect are replicated across a spectrum of most common risky behaviors. Our work demonstrates how social contexts can enhance or reduce a genetic effect on risky behaviors.