INVESTIGATING SUCCESS BIASED TRANSMISSION, AND LONG-TERM MEMORY CAPABILITIES, IN CHIMPANZEES AND CHILDREN: IMPLICATIONS FOR CUMULATIVE CULTURE.

Abstract

Cumulative culture denotes the arguably human capacity to build on the developments of our predecessors. Factors such as imitation, teaching and cultural transmission biases have been identified as important for cumulative culture. In this thesis factors with implications for cumulative culture were investigated in chimpanzees and 4-to 5-year old children. Two experiments were designed to assess success biased copying in chimpanzees (and children) and a third study investigated chimpanzees’ retention and transfer of complex tool use skills. Information pertaining to success derived from others’ performances influenced both chimpanzees and children’s subsequent actions during a video based foraging task and token exchange task. Specifically, some of the first evidence for public information use and payoff biased transmission was documented in both species and thus suggests that a lack of such assessment abilities does not underlie the lack of cumulative culture in chimpanzees. In the final empirical study, some of the first evidence for appreciable long-term memory and improvements in the utility of complex tool manufacture was documented in chimpanzees. High fidelity retention of (socially) learned information is important for cumulative culture, where behaviour must be retained with sufficient fidelity for it to be reproduced. This is especially so where, for example, tool use is required to access temporally rare resources (e.g. nuts falling certain months of the year/seasonal resources).