Do Genes Predict Friendship Networks? The Mitigating Role of School Context

Benjamin Domingue, University of Colorado at Boulder
Jason D. Boardman, University of Colorado at Boulder
Jason Fletcher, Yale University

Recent research suggests that the genotype of one friend in a friendship pair is predictive of the genotype of the second friend. These results provide tentative support for the genetic homophily perspective which has important implications for genetic and social epidemiology because it evidences a particular form of gene-environment correlation. This factor may have important implications for both environmental and genetic estimates on health and health-related behaviors that are of interests to social demographers. We extend this work by considering the ways in which school context shapes genetically similar friendships. Using the network, school, and genetic information from the National Longitudinal Study of Adolescent Health, we show that genetic homopily for the TaqI A polymorphism within the DRD2 gene is stronger in schools with greater levels of inequality. Our results highlight the fundamental role played by broad social structures in the extent to which genetic factors explain complex behaviors.