Unearthing the Foundations: Testing the Universality of Moral Foundations Theory in Three Small-Scale Populations

Moral Foundations Theory proposes five universal moral domains—Care, Fairness, Loyalty, Authority, and Purity—but its empirical support has largely been drawn from affluent, highly educated societies. This limits both the generalisability of the framework and our understanding of the socioecological factors that shape morality. To address this gap, we tested Moral Foundations Theory in three non-industrialised populations: Hadza hunter-gatherers, Datoga pastoralists, and Iraqw agropastoralists. We developed the Moral Foundations Boards, a novel pictorial tool designed to assess sensitivity to violations of the five moral foundations in low-literacy contexts. Participants completed the Moral Foundations Boards, while a sample from the United States served as a comparative reference and completed additional standard measures—the Moral Foundations Questionnaire and the Moral Foundations Vignettes. Although the five-factor structure of Moral Foundations Theory did not consistently emerge, we found cross-cultural variation. Hadza and Datoga participants showed greater sensitivity to Purity-related violations and reduced sensitivity to Care-related violations compared to participants from the United States. These findings challenge claims of structural universality in Moral Foundations Theory and underscore the importance of incorporating diverse socioecological contexts into the study of moral psychology.