LAUSR

Significance Deciphering the underlying psychology of societal attitudes and prejudices is important in times of political unpredictability. We focus on the foundational construct of preference for (or against) hierarchies between groups, as reflected in the 2 subdimensions of social dominance orientation (SDO). Studying SDO with a large-sample twin design, we show that both its sub-dimensions are heritable, share common genetic influences, and overlap genetically with 6 political attitudes that serve to enhance versus attenuate societal hierarchy. This suggests that desire for versus opposition to intergroup hierarchy, in abstract and concrete forms, constitutes a genetically-grounded behavioral syndrome, thus explaining an important part of the long-observed association among political views of various kinds. A foundational question in the social sciences concerns the interplay of underlying causes in the formation of people’s political beliefs and prejudices. What role, if any, do genes, environmental influences, or personality dispositions play? Social dominance orientation (SDO), an influential index of people’s general attitudes toward intergroup hierarchy, correlates robustly with political beliefs. SDO consists of the subdimensions SDO-dominance (SDO-D), which is the desire people have for some groups to be actively oppressed by others, and SDO-egalitarianism (SDO-E), a preference for intergroup inequality. Using a twin design (n = 1,987), we investigate whether the desire for intergroup dominance and inequality makes up a genetically grounded behavioral syndrome. Specifically, we investigate the heritability of SDO, in addition to whether it genetically correlates with support for political policies concerning the distribution of power and resources to different social groups. In addition to moderate heritability estimates for SDO-D and SDO-E (37% and 24%, respectively), we find that the genetic correlation between these subdimensions and political attitudes was overall high (mean genetic correlation 0.51), while the environmental correlation was very low (mean environmental correlation 0.08). This suggests that the relationship between political attitudes and SDO-D and SDO-E is grounded in common genetics, such that the desire for (versus opposition to) intergroup inequality and support for political attitudes that serve to enhance (versus attenuate) societal disparities form convergent strategies for navigating group-based dominance hierarchies.