Learning the lessons of tit-for-tat: Even competitors can get the message

The tit-for-tat strategy is known for its ability to train cooperation duri ng an iterated 2-person prisoner's dilemma. In this research, a repeated me asures design was used to assess the nature and long-term persistence of su ch training. One month after playing against a programmed tit-for-tat strat egy, participants returned to the lab to play a randomly matched other part icipant. Participants increased their levels of cooperative behavior, both during the 1st sequence and in the 2nd sequence compared with the first. Di spositional competitors increased the most from the 1st to the 2nd sequence and also gained the most new respect for opponents' self-interestedness fo llowing the Ist sequence. This suggests that competitors may be individuali sts at heart and that the "punitive" feature of tit-for-tat (R. Axelrod, 19 84) is important for eliciting enhanced cooperation from such opponents.