Abstract # 13428 Poster # 92:

Scheduled for Thursday, August 22, 2019 06:00 PM-08:00 PM: (Alumni Lounge) Poster Presentation


HUMANS AND CAPTIVE CAPUCHIN MONKEYS (CEBUS [SAPAJUS] APELLA) AND RHESUS MACAQUES (MACACA MULATTA) SOLVE THE MONTY HALL DILEMMA IN A COMPUTERIZED TASK

J. Watzek, W. Whitham, D. A. Washburn and S. F. Brosnan
Georgia State University, Department of Psychology, Language Research Center, Atlanta, GA 30302, USA
line
     The Monty Hall Dilemma (MHD) is a probability puzzle with a counterintuitive solution. Participants initially choose among three doors, one of which conceals a prize. A different door is opened and shown to be empty. Participants are then asked whether they would like to stay with their original choice or switch to the other remaining door. Although switching doubles the chances of winning, people overwhelmingly stay with their original choice. To assess how experience and the chance of winning affect decisions in the MHD, we used a comparative approach to test 264 students, 24 capuchin monkeys, and 7 rhesus monkeys on a nonverbal, computerized version of the game. Participants repeatedly experienced the outcome of their choices and we varied the chance of winning by changing the number of doors (3 or 8). All species quickly and consistently learned to switch doors, especially in the 8-door condition, t(75.47)=-3.01, p=.004. However, humans failed to generalize the successful switch strategy from the computer task to the classic text version of the MHD, chi2(2)=8.66, p=0.013. Instead, participants showed their characteristic tendency to stick with their pick, regardless of the number of doors. This disconnect between strategies in the classic version and a repeated nonverbal task with the same underlying probabilities may arise because they evoke different decision-making processes, such as explicit reasoning vs. implicit learning.