Self‐control in a Prisoner's Dilemma game: the role of trial spacing and an interfering task

Self‐control was studied in an iterated one‐player Prisoner's Dilemma game in which students' choices affected the payoff matrix on the next trial. The frequency of self‐control responses (choice of the smaller payoff now, but with the more generous payoff matrix more likely on the next trial) and defection responses (choice of the larger payoff now, but with the less generous payoff matrix more likely on the next trial) were measured. In Experiment 1, players achieved a criterion of five consecutive self‐control responses more quickly as a positive function of trial spacing, the presence between trials of a discriminative stimulus associated with the upcoming payoff matrix, and the probability that the self‐control or defection response would be reciprocated by the computer. Experiment 2 replicated the effect of trial spacing except when there was an interfering task during the interval, suggesting that trial spacing permits better appreciation of the contingencies. Copyright © 2006 John Wiley & Sons, Ltd.