Cooperative and conformist behavioural preferences predict the dual dimensions of political ideology

Decades of research suggest that our political differences are best captured by two dimensions of political ideology. The dual evolutionary framework of political ideology predicts that these dimensions should be related to variation in two social preferences inherent to group living: cooperation and group conformity. Here, we combine data from a nationally representative survey and a suite of incentivised behavioural tasks to test whether cooperative and conformist preferences predict widely used measures of the two dimensions of political ideology - Social Dominance Orientation (SDO) and Right Wing Authoritarianism (RWA) - and a host of related policy views. As predicted, we find that cooperative behaviour predicts lower SDO and economically progressive policy views, and conformist social information use (though not rule following or norm enforcement) predicts higher RWA and socially conservative policy views. These findings reveal how evolved cooperative and conformist preferences continue to shape our political differences even today.