Anne Pisor's public dissertation defense

Unlike non-human primates, humans are highly tolerant of out-group strangers, as evidenced by the ethnographic and archaeological records; however, very little research has addressed when and why people build relationships with out-group individuals. What selection pressures might have favored inter-group relationship building in humans? As smoothing resource access has been crucial in the human foraging ecology, I suggest that relationships with out-group members may provide access to non-local resources and buffer resource shortfalls striking entire communities. The relevance of out-group relationships is not limited to small-scale or prehistoric contexts either, as out-group members can also provide access to difficult-to-access resources like market items. My research program is focused on the above question; in my dissertation, I address three components of it: Which social and ecological factors favor out-group relationships? What do people look for when picking partners from out-groups? When people value out-group members, will they avoid costly behavior to avoid harming out-group members? I will present data from three populations of Bolivian horticulturalists and the World Values Survey that provide some preliminary answers.