Sociology & Anthropology, Ohio University
Thursday 8:15-8:30, Grand Ballroom II
Costly signals are public signals that incur actual or potential costs to senders, and provide information about their phenotypic quality to potential mates, allies or competitors. Costly signaling has been observed in multiple human communities, particularly among young males, and costly signaling theory (CST) has been used to explain risky behaviors among those males. Previous research has suggested that chimpanzees engage in costly signaling, especially during risky behaviors such as boundary patrols and hunting, but no studies have explicitly applied CST to data on young (juvenile, adolescent and young adult) male chimpanzee behavior. I present comparative data on the behaviors of young male chimpanzees and humans during risky behaviors that address this gap, and provide information relevant to behavioral reconstructions of early Hominins. I collected data on young male chimpanzee participation in and behavior during boundary patrols and hunting during a 16-month study at Ngogo Kibale National Park, Uganda. I used published and unpublished data on young male human participation in risky behaviors. Young male chimpanzees and humans engage in costly signaling, and their willingness to take risks increases with age. Further, their participation in risky behaviors impacts their ability to attract social partners and potential allies. These results indicate that costly signals are important social tools used by male chimpanzees and humans during social development to communicate quality as a social partner, and to assess potential allies. When combined the two sets of results indicate that costly signaling was likely an important tool for our earliest Hominin ancestors.
This research was funded by the L.S.B. Leakey Foundation, the Andrew Mellon Foundation, Sigma Xi, Yale University and Ohio University.