Abstract # 36:

Scheduled for Saturday, September 13, 2014 03:45 PM-04:00 PM: Session 10 (Henry Oliver) Oral Presentation


K. Hall1,2,3, M. J. Beran2,3, B. J. Wilson4, S. P. Lambeth1, S. J. Schapiro1 and S. F. Brosnan1,2,3
1UT MD Anderson Cancer Center, Michale E. Keeling Center for Comparative Medicine and Research, 650 Cool Water Dr, Bastrop, TX 78602, USA, 2Georgia State University, 3Language Research Center, 4Economic Science Institute, Chapman University
     We tested multiple pairs of chimpanzees (Pan troglodytes) in two economic games to determine how flexibly they can switch strategies during games with different payoffs. Each pair participated in ten 60-trial sessions of Chicken game (hawk and dove choices), followed by ten alternating sessions of Chicken and Assurance (stag and hare choices) games. Subjects must coordinate (Assurance) or anti-coordinate (Chicken) their responses to obtain maximum rewards. Pairs of subjects were tested indoors. Attached to the inside of the cage were two buckets, each filled with ten pairs of colored tokens. Each game utilized a unique pair of tokens. Subjects exchanged tokens with an experimenter; tokens were placed on a suspended tray, and then appropriate numbers of grapes were simultaneously distributed to each subject in full view of the other. Currently, three pairs have completed the Chicken game, with one showing a consistent strategy (anti-coordination: chi-squared=36.507, df=1, p<0.0001). Of the four remaining individuals, only one showed a consistent choice (hawk: binomial test, p<0.05). The first two of those pairs have completed the alternating Assurance and Chicken games and neither pair’s choices differed from chance for either game, possibly indicating the challenge of maintaining a strategy in a shifting environment. We therefore have not found evidence that chimpanzees flexibly switch between strategies to maximize payoffs, but continue to explore whether this may occur with additional experience.