2013 EAS Paper Presentation Awards

The EAS gives out two awards per year, based on presentations at the AAA meetings. The awards are for best paper by a new investigator and best paper by a student, and they are awarded with a cash prize.

Best Paper by a New Investigator (2-way tie)

Drew Gerkey Risk-Pooling, Resilience, and Common-Pool Resources in Siberia: Synthesizing Field Experiments and Ethnography

Abstract: Research on cooperation focuses on strategic risks—the potential costs and benefits of choosing a strategy in a social context shaped by the actions of other people. But social dilemmas often entail environmental risks as well, where people are affected by unpredictable shocks and other misfortunes. Risk-pooling is one strategy for adapting to environmental risks that has intrigued evolutionary theorists, economists, and ethnographers alike. If the strategic risks of pooling resources can be overcome, groups facing unpredictable environments can thrive where individuals acting alone struggle to survive. We present results from a new field experiment, conducted with common-pool resource users in rural villages in Siberia and Alaska. Our design builds on a multi-round public goods game, systematically varying strategic and environmental risks in order to understand the emergence of risk-pooling strategies. Our methods allow us to explore the impact of reputational dynamics, environmental shocks, and communication on risk-pooling strategies. Using survey data on social networks of support, interviews, and participant observation, we explore how decisions in these field experiments correspond to actions in naturally occurring contexts of cooperation in Siberia and Alaska.

Brian Wood The Hadza and the Honeyguide Bird

Abstract: When Hadza hunter-gatherers of northern Tanzania search their woodlands for sources of wild honey, they are often helped by a bird they call Tikiliko, which leads them to hives of the African honeybee, Apis mellifera. This bird is known appropriately in English as the Greater Honeyguide (Indicator indicator). Relying upon observations carried out between 2006-2012, this paper describes how honeyguides and Hadza interacted, tests whether honeyguides changed the Hadza’s efficiency at finding honey, calculates the fraction of the Hadza diet that was acquired with honeyguides’ help, examines how and why the Hadza manipulate honeyguides, and considers the co-evolution of the relationship. We find that honeyguides provided a 7-fold increase in men’s rate of encountering beehives. Honeyguides’ only led men to hives of A. mellifera, which produced larger stores of honey and brood than any of the other local bee species. Interestingly, honeyguides led Hadza to significantly higher-yielding hives of A. mellifera than those found without honeyguides’ help. The bird plays a very important role in the Hadza diet: 57% of all the honey and brood calories that men acquired came from hives found with honeyguides’ help. Surprisingly, not once did a Hadza ever actively repay a honeyguide; on the contrary, if they ever acted to influence the bird’s payoff, it was to reduce it. Even so, available evidence generally supports the hypothesis that early human ancestors partnered with the bird, leading to the evolution of this extraordinary relationship.

Best Student Paper

Glowacki, Luke (Harvard U) - Raiding Party Formation, Composition, and the Collective Action Problem: Results From an East African Pastoralist Society

Abstract: Participation in warfare in small-­-scale societies presents an especially salient example of collective action. Warriors take significant mortality risks to produce non-­-excludable benefits such as deterrence and territorial expansion. Little is known about inter-­-individual variation in participation or the formation of raiding parties. Do individuals participate uniformly in conflict, or is there significant variation? Is raiding party leadership stable across raids? Answers to questions such as these have important implications for understanding how collective action problems are solved in small-­-scale societies. Using data on warfare obtained from nomadic pastoralists in southwest Ethiopia, I show 1) significant inter-­-individual participation on raiding parties for 120 males, 2) raiding party composition for 21+ raids and 3) stable group leadership on 21+ raids. Together these provide data to test theories of collective action.