The Dual Foundations of Political Ideology Are Ubiquitous across Human Social Life

Many people in Western countries represent the political landscape as a single dimension of conflict: authority, hierarchy, and tradition on the right versus greater freedom, equality, and systemic change on the left. Here, we argue that politics comprises not one but two primary dimensions. Moreover, these two dimensions are not unique to modern nations but reflect two evolutionary trade-offs that we call the “dual foundations” of politics and argue are inherent to human social life. One foundation concerns the trade-off between cooperation and competition and gives rise to contestation over levels of inequality and provision of public goods. The other foundation concerns the trade-off between autonomy and conformity, leading to contestation over the extent of social control. Drawing on anthropological, psychological, and historiographical evidence, we argue that these dual foundations are contested across the diversity of human lifeways and lead to two cross-culturally ubiquitous dimensions of ideology. As such, the dual foundations provide a common evolutionary framework for studying human politics across geography, history, subsistence styles, levels of social organization, and academic disciplines. We end by outlining how quantitative approaches to studying the dual foundations beyond industrialized nations can advance research on both the anthropology and psychology of political ideology.