title: Contingencies of reinforcement in a five-person prisoner's dilemma.
abstract: As in studies of self-control, a tit-for-tat contingency in an iterated prisoner's dilemma game creates a conflict between maximization of local and global reinforcement. The present experiments examine this conflict in a multiplayer prisoner's dilemma game. Versus tit for tat, cooperation corresponds to self-control; defection, always immediately reinforced, corresponds to impulsiveness. Three experiments examined sensitivity of behavior to the global reinforcement contingency imposed by tit for tat. Undergraduates played a five-player prisoner's dilemma game against four dummy players programmed to play tit for tat or randomly. With tit for tat, a player's cooperation (or defection) increased dummy players' cooperation (or defection) on subsequent trials-reinforcing cooperation and punishing defection in the long run. Participants cooperated at a higher rate when the dummy players played tit for tat than when the dummy players played randomly. These results are consistent with findings in corresponding studies of self-control. Some participants, caught in a trap of mutual defection with the tit-for-tat playing dummy players, came to cooperate when the tit-for-tat contingency was reset ("forgiving" participants' previous defections) during a pause in the game. This increase was a result of the combined effects of a pause and reset; neither pausing nor resetting independently resulted in an increase in cooperation.
authors.affiliation: State University of New York at Stony Brook, USA. ryi@uvm.edu
authors.forename: Richard
authors.initials: R
authors.lastname: Yi
authors.forename: Howard
authors.initials: H
authors.lastname: Rachlin
mesh_terms: D000328:Adult; D003220:Conflict, Psychological; D005260:Female; D006801:Humans; D008297:Male; D011329:Prisoners / Q000523:psychology*; D012054:Reinforcement, Psychology; D011795:Surveys and Questionnaires