Audience presence influences cognitive task performance in chimpanzees.

Human cognitive performance can be significantly influenced by the presence of audience members. While often associated with reputation management, which is considered uniquely human, it is unclear to what degree this phenomenon is shared with non-human animals. To investigate such audience effects in chimpanzees, we recorded the performance of six chimpanzees on three different numerical touch screen tasks varying in difficulty and cognitive demand, in the presence of variable audience member compositions over six years. Our results indicated that chimpanzee performance was influenced by the number and types of audience present. Performance increased for the most difficult task as the experimenter count increased, while for the easiest task, performance decreased as familiar audience and experimenter count increased. This suggests that audience effects on cognitive processing can be found in chimpanzees and that the evolutionary roots of this trait may date back to before the development of reputation-based normative societies in humans.