A new study finds that genes significantly affect variation in voter turnout, shedding new light on the reasons why people vote and participate in the political system.

"Although we are not the first to suggest a link between genes and political participation," note the authors, "this study is the first attempt to test the idea empirically."

They do so by conducting three tests of the claim that part of the variation in political participation can be attributed to genetic factors. The results suggest that individual genetic differences make up a large and significant portion of the variation in political participation, even after taking socialization and other environmental factors into account. They also suggest that, contrary to decades of conventional wisdom, family upbringing may have little or no effect on children's future participatory behavior.

In conducting their study, the authors examine the turnout patterns of identical and non-identical twins—including 396 twins in Los Angeles County and 806 twins in the National Longitudinal Study of Adolescent Health. Their findings suggest that 53% of the variation in turnout can be accounted for by genetic effects in the former, with similar outcomes in the latter.

Moreover, genetic-based differences extend to a broad class of acts of political participation, including donating to a campaign, contacting an official, running for office, and attending a rally. According to Fowler, "we expected to find that genes played some role in political behavior, but we were quite surprised by the size of the effect and how widely it applies to all kinds of participation."

"The fact that we have found genetic variation in voting, and political participation in general, should not be surprising given the large numbers of behaviors that have already been found to be heritable," observe the authors. They conclude by noting that "the next step in this line of research must move beyond estimates…and attempt to identify why genes matter so much." Some potential avenues include examining the interaction of genes and the environment on political participation, tracing the connections between participation in small groups and large-scale participation, and identifying the genes or groups of genes implicated in political behavior.

The research, conducted by political scientists James H. Fowler, Christopher T. Dawes (of UC San Diego) and psychologist Laura A. Baker (of University of Southern California), appears in the May issue of the American Political Science Review, a journal of the American Political Science Association (APSA). The article is available online at: www.apsanet.org/imgtest/APSRMay08Fowler_etal.pdf.