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.In his influential collection of essays, Ideology and Utopia, Karl Mannheim (1936) sought to explain the meaning and origin of political ideology. As a founder of the "sociology of knowledge" school of thought, he broadened a view, first championed by Marx, that individual political attitudes are derived from groups and their relationships to the whole of society. While Marx focused particularly on class relations, Mannheim observed that political ideology is the product of the total social context of each individual. To understand a person's political ideology, we need only examine his or her political environment.Mannheim's work would influence several generations of scholars (e.g., Huntington 1957;Bell 1959;Rapoport 1974;North 1978;Lipset 1983;Jackman and Muha 1984;Haas 1992). While many of these scholars disagreed with parts of Mannheim's argument, they all agreed with the premise: that the social and institutional environment is paramount for explaining a person's political attitudes and beliefs. When individuals say they are "liberal" or "conservative," they are referring to their ideas about the issues of the day that are specific to a place and a moment in history. Remove them to another context and their ideology will change.This literature contrasts with a growing body of work that suggests ideology is not purely a product of the social environment or historical moment. Increasingly, it is becoming Contact author James Fowler, jhfowler@ucsd.edu. Most recent version available at http://jhfowler.ucsd.edu. NIH Public AccessAuthor Manuscript J Polit. Author manuscript; available in PMC 2012 January 24. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript apparent that political ideology also has a "core" eleme...

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