We describe food transfer patterns among Ache Indians living on a permanent reservation. The social atmosphere at the reservation
is characterized by a larger group size, a more predictable diet, and more privacy than the Ache typically experience in the
forest while on temporary foraging treks. Although sharing patterns vary by resource type and package size, much of the food
available at the reservation is given to members of just a few other families. We find significant positive correlations between
amounts transferred among pairs of families, a measure of the "contingency" component required of reciprocal altruism models.
These preferred sharing partners are usually close kin. We explore implications of these results in light of predictions from
current sharing models.
Key words Cooperation - Food sharing - Hunter-gatherers - Reciprocity
This research was supported by an L.S.B. Leakey Foundation grant and an NSF Graduate Fellowship to M. Gurven, and NSF Grant
#9617692 to K. Hill and A. M. Hurtado.
Michael Gurven recently obtained his Ph.D. from the University of New Mexico and is now an assistant professor at UC-Santa
Barbara. His current interests include exploring ways in which socioecology influences variation in cooperation within and
across human groups, and how cultural norms of fairness co-evolve with systems of resource production and distribution.
Wesley Allen-Arave is pursuing his Ph.D. in anthropology at the University of New Mexico. His primary research interests focus
on exploring variations across time and space in nonreciprocated altruistic acts, cooperation within social networks, and
concerns over social approval.
Kim Hill is a professor of anthropology in the Human Evolutionary Ecology (HEE) program at the University of New Mexico. His
primary research interests include hunter-gatherer behavioral ecology, life history theory, food acquisition strategies, food
sharing, cooperation, and biodiversity conservation in lowland South America. He has done fieldwork with Nahautl, Ache, Guarani,
Hiwi, Mashco Piro, Matsiguenga, and Yora indigenous peoples of Central and South America.
A. Magdalena Hurtado is associate professor of anthropology at the University of New Mexico. Her research interests include
the evolution of cooperation between the sexes, infectious disease and immune system adaptations, the epidemiology of hunter-gatherer
societies in transition, and the effects of health on economic productivity. During the past 20 years she has conducted fieldwork
among several South American native populations but now works primarily among the Ache of eastern Paraguay.