Studies of identical and fraternal twins suggest that political ideology has a heritable component...but no specific gene associated with...political ideology has so far been identified. Using data from the National Longitudinal Study of Adolescent Health, we investigate the moderating influence of friendships on the contribution of the 7R allele of the DRD4 gene to liberal political ideology. The number of self-nominated friendships in adolescence moderates the influence of the gene on political ideology; the more friends nominated, the stronger the liberal ideological identification of the respondent in early adulthood. This is the first study to elaborate a specific gene-environment interaction that contributes to ideological self-identification.

Labels: Behavior Genetics