title: Commitment and self-control in a prisoner's dilemma game.
abstract: Humans often make seemingly irrational choices in situations of conflict between a particular smaller-sooner reinforcer and a more abstract, temporally extended, but larger reinforcer. In two experiments, the extent to which the availability of commitment responses-self-imposed restrictions on future choices-might improve self-control in such situations was investigated. Participants played a prisoner's dilemma game against a computer that played a tit-for-tat strategy-cooperating after a participant cooperated, defecting after a participant defected. Defecting produced a small-immediate reinforcer (consisting of points convertible to gift cards) whereas cooperating increased the amount of subsequent reinforcers, yielding a greater overall reinforcer rate. Participants were normally free to cooperate or defect on each trial. Additionally, they could choose to make a commitment response that forced their choice for the ensuing five trials. For some participants, the commitment response forced cooperation; for others, it forced defection. Most participants, with either commitment response available, chose to commit repeatedly despite a minor point loss for doing so. After extended exposure to these contingencies, the commit-to-cooperate group cooperated significantly more than a control group (with no commitment available). The commit-to-defect group cooperated significantly less than the control group. When both commitment alternatives were simultaneously available-one for cooperation and one for defection-cooperation commitment was strongly preferred. In Experiment 2, the commitment alternative was removed at the end of the session; gains in cooperation, relative to the control group, were not sustained in the absence of the self-imposed behavioral scaffold.
authors.affiliation: Psychology Department, Stony Brook University, Stony Brook, NY 11794, USA. matthew.locey@stonybrook.edu
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Locey
authors.forename: Howard
authors.initials: H
authors.lastname: Rachlin
mesh_terms: D002755:Choice Behavior; D003220:Conflict, Psychological; D003299:Cooperative Behavior; D005260:Female; D005717:Games, Experimental; D006801:Humans; D007389:Internal-External Control; D008297:Male; D012054:Reinforcement, Psychology; D013997:Time Factors; D014040:Token Economy