Gene–culture interactions: a multi-gene approach

Abstract

Previous studies have identified genetic variants linked to increased susceptibility to socio-cultural influences. These studies typically show that individuals with the more susceptible variant of a specific polymorphism exhibit social behavior more in accordance with surrounding cultural norms. Given limitations of the single gene approach, we propose to assess genetic susceptibility with a multi-gene index, composed of polymorphisms previously identified in gene–culture interaction studies. Specifically, we are interested in whether the combined susceptibility index moderates cultural differences in self-expression. In the present study, Americans and Koreans completed psychological and behavioral assessments of self-expression tendencies and provided DNA samples, which were genotyped for preselected OXTR, 5HTR1A, SERT, and DRD4 polymorphisms. Results show that the genetic susceptibility index predicts a wider range of self-expression outcomes than what is predicted by individual polymorphisms. The findings underscore the importance of developing biologically and functionally informed models of genetic influence. Further the work demonstrates a model for examining the effects of multiple genes simultaneously and advances our understanding of how genetic and socio-cultural factors jointly contribute to shape social behaviors.