Publications of Christopher T. Dawes

Genetic Influences on Political Ideologies: Twin Analyses of 19 Measures of Political Ideologies from Five Democracies and Genome-Wide Findings from Three Populations

Almost 40 years ago, evidence from large studies of adult twins and their relatives suggested that between 30 and 60 % of the variance in social and political attitudes could be explained by genetic influences. However, these findings have not been widely accepted or incorporated into the dominant paradigms that explain the etiology of political ideology. This has been attributed in part to measurement and sample limitations, as well the relative absence of molecular genetic studies. Here we present results from original analyses of a combined sample of over 12,000 twins pairs, ascertained from nine different studies conducted in five democracies, sampled over the course of four decades. We provide evidence that genetic factors play a role in the formation of political ideology, regardless of how ideology is measured, the era, or the population sampled. The only exception is a question that explicitly uses the phrase “Left–Right”. We then present results from one of the first genome-wide association studies on political ideology using data from three samples: a 1990 Australian sample involving 6,894 individuals from 3,516 families; a 2008 Australian sample of 1,160 related individuals from 635 families and a 2010 Swedish sample involving 3,334 individuals from 2,607 families. No polymorphisms reached genome-wide significance in the meta-analysis. The combined evidence suggests that political ideology constitutes a fundamental aspect of one’s genetically informed psychological disposition, but as Fisher proposed long ago, genetic influences on complex traits will be composed of thousands of markers of very small effects and it will require extremely large samples to have enough power in order to identify specific polymorphisms related to complex social traits.

Sense of Control and Voting: A Genetically Driven Relationship

Objectives The impact of political efficacy on political participation has been established in numerous classical studies of political behavior. However, the effects of more general measures of efficacy on political efficacy and voter turnout have received almost no attention. Additionally, seemingly independent contemporary developments in the field of political science proposed that political participation is heritable. In this study, we propose to link the two literatures, highlighting one possible mechanism through which genetic inheritance of political behavior is possible in the absence of the evolutionary time horizons of voting behavior. We theorize that heritability of psychological dispositions, such as one's sense of control, is more plausible and indirectly, through political efficacy, could have an influence on one's decision to vote. Methods We test our hypotheses using a classical twin study design (ACE models) and Cholesky decomposition models on data from the MIDUS (first wave) and MNTPS twin surveys. Results Empirically we find a relationship between general efficacy and turnout. We show that numerous operationalizations of efficacy are highly heritable and their covariance with turnout is predominantly driven by underlying additive genetic sources. On the other hand, environmental covariation between general and political efficacy and turnout is not significantly different from zero. Conclusions Our analysis contributes to a better understanding of how one's sense of control influences voting behavior. Our results provide sufficient evidence to claim that the covariation between these two traits can primarily be attributed to genetic factors. However, this is certainly not the only pathway that explains the heritability of voter turnout.