Aimee Plourde: UCLA Dept. of Anthropology

The emergence of social ranking and political hierarchy in human society constituted a fundamental departure from the small, egalitarian group structure thought to characterize society for most of our species’ history. Explaining the origins of social ranking is thus key to understanding the underlying structures of modern human societies, and the evolutionary processes that have generated them. Archaeologists have argued that the emergence of an economy of prestige goods in prehistory provided a critical means for leaders in chiefdom-level societies to attract followers and establish hierarchical relations with elites in neighboring polities. However, these arguments fail to explain the initial attraction of prestige goods themselves. Here I present a model for the evolution of psychological mechanisms that value prestige goods, and outline the evolving role of prestige goods in the negotiation of hierarchy at increasing levels of political ranking. This model is assessed against archaeological excavation and survey data collected in the northern Lake Titicaca Basin of highland Peru. The data demonstrate that strong correlations exist between increasing polity size and political hierarchy on the one hand and increasingly direct control of the trade routes used to procure prestige items on the other.