Experimental Study of Repeated Team-Games

Gary Bornstein, Eyal Winter & Harel Goren

We report an experiment in which the Intergroup Prisoner's Dilemma (IPD) game was contrasted with a structurally identical (single-group) Prisoner's Dilemma (PD). The games were played repeatedly for 40 rounds. We found that subjects were initially more likely to cooperate in the IPD game than in the PD game. However, cooperation rates decreased as the game progressed and, as a result, the differences between the two games disappeared. This pattern is consistent with the hypothesis that subjects learn the structure of the game and adapt their behavior accordingly. Computer simulations based on a simple learning model by Roth & Erev (1995) support this interpretation.

January, 1996
Published in: 
European Journal of Political Economy 12 (1996), 629-639