Emergence of inequality within human societies

All human societies exhibit socially mediated inequalities among individuals or groups, but only relatively late in the history of our species do these inequalities assume the form of institutionalized differences in power and wealth. Smith applies evolutionary game theory and agent-based modeling to understand the emergence of such institutionalized inequalities, which emerged repeatedly both pre-agriculture (e.g., among the NW Coast Indians) and well afterwards. Although there is a large social science literature on this problem, formal models are rare. Smith’s work (with economist J.-K. Choi and archaeologist J. Boone) focuses on developing such models, both analytical (using evolutionary game theory) and computational (using agent-based simulation). To date they have developed two sets of models (Smith & Choi in press). One is based on mutually profitable exchanges between patrons (who defend resource-rich territories) and clients (who exchange services for a share of a patron’s resources). The other involves a division of labor between producers who cooperate to produce a collective good and a “manager” who enforces this cooperation (monitoring and punishing defectors) in return for a management fee, thus solving an n-player prisoner’s dilemma. The models contain demographic, economic, and environmental parameters, and involve standard replicator dynamics (which could apply equally to genetic or cultural variation) to convert strategy payoffs into population-level evolution. The eventual goal is to develop an expanded set of alternative models that can generate hypotheses to be tested empirically with archaeological and historic data. We plan to involve IPEM Fellows in several aspects of this work, from simulation model building and refinement, to empirical evaluation of alternative models and comparative analysis of human and non-human systems of inequality and their evolutionary dynamics.