title: Friendships Moderate an Association Between a Dopamine Gene Variant and Political Ideology.
abstract: Scholars in many fields have long noted the importance of social context in the development of political ideology. Recent work suggests that political ideology also has a heritable component, but no specific gene variant or combination of variants associated with political ideology have so far been identified. Here, we hypothesize that individuals with a genetic predisposition toward seeking out new experiences will tend to be more liberal, but only if they are embedded in a social context that provides them with multiple points of view. Using data from the National Longitudinal Study of Adolescent Health, we test this hypothesis by investigating an association between self-reported political ideology and the 7R variant of the dopamine receptor D4 gene (DRD4), which has previously been associated with novelty seeking. Among those with DRD4-7R, we find that the number of friendships a person has in adolescence is significantly associated with liberal political ideology. Among those without the gene variant, there is no association. This is the first study to elaborate a specific gene-environment interaction that contributes to ideological self-identification, and it highlights the importance of incorporating both nature and nurture into the study of political preferences.
authors.affiliation: Political Science Department, University of California, San Diego, 9500 Gilman Drive 0521, La Jolla, CA 92093-0521, USA2.
authors.forename: Jaime E
authors.initials: JE
authors.lastname: Settle
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Dawes
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Christakis
authors.forename: James H
authors.initials: JH
authors.lastname: Fowler