Science2010sglobalhigh confidence

During food competition experiments, male bonobos' cortisol levels increased when a dominant partner was expected to monopolize food and decreased when food was expected to be shared, whereas male chimpanzees showed changes in testosterone instead.

Notes on verification

Confirmed by peer-reviewed PNAS study (Wobber et al. 2010), corroborated by PubMed abstract and independent secondary sources (NBC News, anthropology blog). [tier=gold indep_score=1.0 clusters=3 claim_tier=notable]

Sources