Abstract # 120:

Scheduled for Saturday, August 26, 2017 04:45 PM-05:00 PM: (National Ballroom Salon A) Oral Presentation


AUDIENCE EFFECTS ON CHIMPANZEE DECISION-MAKING IN THE PRIMATE GAMBLING TASK

D. Proctor1,2, K. Burke2 and F. B. de Waal2
1Florida Institute of Technology, 150 W. University Blvd., Melbourne, FL 32901, USA, 2Living Links Center, Yerkes National Primate Research Center
line
     

There is debate about whether nonhuman species are sensitive to third-party image scoring or reputation building. In humans, audience effects during gambling, result in differential risk-taking. Here, we use chimpanzees (Pan troglodytes) to explore the influence of audience rank in a gambling task. Chimpanzees (1 male; 4 females) were presented with a computerized PGT where a close-up video of another chimpanzee’s face (the alpha female or lowest-ranking female) or a nonsocial video was displayed during the task. The chimpanzees chose between two symbols, one represented a small, consistent reward and the other represented a more variable payout including zero outcomes. A repeated measures ANOVA indicated there was a significant difference between conditions [F(2) = 4.913, p = 0.041, partial η2 = 0.551]. Post-hoc contrasts indicated that the mean percentage of choices for the high-variability payout structure was significantly different between the high-ranking (M = 43.20, SD = 4.87) and low-ranking (M = 55.80, SD = 7.40) conditions (F(1) = 18.547, p = 0.013, partial η2 = 0.823). The nonsocial condition (M = 50.60, SD = 6.19) was not significantly different than either of the other conditions. Thus, chimpanzees vary their risk-taking based on their relative status compared to their audience. It is unclear if this is because they want to make an impression on low-ranking individuals or fear repercussions in the presence of dominants.