Cooperative phenotype predicts political ideology eighteen months later

Cross-sectional research has identified robust correlations between cooperative behaviour in economic games and measures of political ideology, but this research is limited in its ability to draw causal inferences. Here, we conducted a longitudinal cross-lagged panel study of cooperation and political ideology with a New Zealand sample (n = 631). Across two waves separated by eighteen months, we measured self-reported political views and employed a battery of economic games to estimate people’s general preferences for cooperation. We found that this “cooperative phenotype” predicted future variation in Social Dominance Orientation and support for income redistribution. Income attribution beliefs and political party support were not related to the cooperative phenotype over time, but did negatively covary with cooperation within waves. In contrast, none of these variables predicted future variation in the cooperative phenotype. These results suggest that cooperative predispositions may play a causal role in the expression of political ideology.