%0 Journal Article %A Samuni, Liran %A Preis, Anna %A Mielke, Alexander %A Deschner, Tobias %A Wittig, Roman M. %A Crockford, Catherine %+ Chimpanzees, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Max Planck Society Chimpanzees, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Max Planck Society The Leipzig School of Human Origins (IMPRS), Max Planck Institute for Evolutionary Anthropology, Max Planck Society Chimpanzees, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Max Planck Society The Leipzig School of Human Origins (IMPRS), Max Planck Institute for Evolutionary Anthropology, Max Planck Society Chimpanzees, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Max Planck Society Endocrinology Laboratory, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Max Planck Society Chimpanzees, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Max Planck Society Chimpanzees, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Max Planck Society %T Social bonds facilitate cooperative resource sharing in wild chimpanzees : %G eng %U https://hdl.handle.net/21.11116/0000-0002-4451-6 %R 10.1098/rspb.2018.1643 %7 2018-10-10 %D 2018 %8 10.10.2018 %* Review method: peer-reviewed %X Why share when access to benefits is uncertain is crucial to our understanding of the evolution of humans' extensive cooperation. Here, we investigated some of the different human sharing hypotheses and potential neuroendocrine mechanisms, in one of our closest living relatives, chimpanzees. The strongest predictor of sharing across food types was the presence of enduring and mutually preferred grooming partners, more than harassment, direct signalling, or trade. Moreover, urinary oxytocin levels were higher after the sharing of both individually and jointly acquired resources compared with controls. We conclude that the emotional connection inherent in social bonds was a key factor determining sharing patterns, with the oxytocinergic system potentially facilitating long-term cooperative exchanges. Testing for the role of social bonds in increasing predictability of sharing behaviour, a feature frequently overlooked, may help us to identify the evolutionary drivers of resource sharing and mechanisms that sustain delayed reciprocity between non-kin. %K Pan troglodytes; cooperation; friendship; oxytocin; harassment %J Proceedings of the Royal Society London B %V 285 %N 1888 %] 20181643 %I The Royal Society Publishing %C London