%0 Journal Article %A Pisor, Anne C. %A Gurven, Michael %+ Department of Human Behavior Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Max Planck Society %T When to diversify, and with whom? Choosing partners among out-group strangers in lowland Bolivia : %G eng %U https://hdl.handle.net/11858/00-001M-0000-002D-FBEB-8 %R 10.1016/j.evolhumbehav.2017.09.003 %D 2018 %* Review method: peer-reviewed %X Evidence from the ethnographic and archaeological records reveals that humans often rely on out-group relationships for access to non-local resources and resource buffering. However, little is known about how actors choose out-group cooperative partners. The existing literature suggests that (in-group) partner choice is based on characteristics associated with greater cooperation (e.g., trustworthiness and productivity). Is out-group partner choice based on the same criteria as in-group? Because out-groups may be unique sources of resource access, we suggest that out-group partner choice should track characteristics of both the candidate partner and the partner's group that are associated with benefits for the actor. To assess partner choice, we employed a non-anonymous, one-shot economic game where participants could allocate money towards in-group and out-group strangers. Participants were from three populations of Bolivian horticulturalists (n = 200) that range in their market integration and their mobility, thus capturing variation in potential benefits to out-group cooperation. We find that individual-level qualities of prospective partners, such as wealth and trustworthiness, affect allocation behavior differently for in-group vs out-group prospective partners. While we find no consistent effects of perceived group qualities on a donor's giving to in-group and out-group members, the relevance of out-group market resource access for Tsimane' donors' allocations suggests that, at least when it comes to dividing a limited resource, qualities associated with a group can affect partner preference. Taken together, results provide insight into patterns of intergroup relationship building that have been crucial in the human lineage. %K Bolivia, Generosity, Horticulturalists, Intergroup contact, Partner choice, Strangers %J Evolution and Human Behavior %V 39 %N 1 %& 30 %P 30 - 39 %I Elsevier %C New York, NY %@ 1090-5138