Monique Borgerhoff-Mulder: University of California, Davis

While the causes, transmission and consequences of material and social inequality are well studied in the social sciences, the ways in which people respond to inequality are less clear. As evolutionary social scientists we know that humans show a strong aversion to inequality, but we have little understanding of how individuals respond behaviourally to disparities in material, social and relational wealth. In this talk I present data from the Pimbwe, a Bantu forager-horticulturalist population in Tanzania undergoing rapid social change and escalating material inequality, to show how both witchcraft accusations and social networks of exchange are patterned by wealth differences. Specifically cooperation among unrelated and related individuals is least pronounced amongst the wealthiest individuals. This observation is used to start theorizing how inequities might favor or disfavour cooperation. A better understanding of such dynamics is important, given the escalating levels of inequality worldwide, consequential on the neoliberal policies associated with globalization.