Charles Efferson, Senior Research Associate, Economics, University of Zurich.
Charles will present two areas of research, both of which emphasize how distinct mechanisms can interact to shape the evolution of human social behavior. The first part of the talk, entitled "Super-Additive Cooperation," presents results from a modeling project and an associated behavioral experiment. Models examine the evolution of cooperation under both repeated interactions within groups and competition between groups. These mechanisms have critical weaknesses in isolation, but when combined they generate large positive interactions. Positive interactions arise from a form of reciprocity that conditions on both the choices and the group affiliation of one's partner. We observe exactly this form of parochial reciprocity in a one-shot trust game with two groups from the Highlands of Papua New Guinea. The second part of the talk, entitled "The Seduction of Applied Conformity," considers if and how policy makers can recruit cultural evolutionary processes to promote socially beneficial changes in behavior. Results from a field study on female genital cutting in Sudan show that individual heterogeneity may be shaping the cultural evolution of harmful practices like cutting far more than development agencies assume. If so, policy makers must examine how individual heterogeneity interacts with social learning in a population of individuals who vary in terms of their preferences and how they learn from others.