Recent research demonstrates that variation in a wide range of political attitudes, beliefs, and behaviors can be explained in part by genetic variation. However, these studies have not yet identified the mechanisms that generate such a relationship. Some scholars have speculated that personality traits mediate the relationship between genes and political behavior, but so far there have been no empirical tests of this conjecture. Here we focus on the role of three psychological traits that are believed to influence political participation: cognitive ability, personal control, and extraversion. Utilizing a unique sample of more than 2,000 Swedish twin pairs, we show that a common genetic factor can explain most of the relationship between these psychological traits and acts of political participation like contacting officials and voting. We also show that a common genetic factor underlies other important political traits related to participation, like internal and external political efficacy, interest in politics, being informed about policy, confidence in politicians, and feelings of civic duty. These are the first results to suggest that the same set of genes influences both psychological traits and political participation, which suggests that psychological traits partially mediate the effect of genes on behavior. They also suggest specific causal pathways that can now be studied in greater detail at the molecular level in order to better understand our political predispositions.
