Cooperators Pay More Attention to the Outcome of Mutual Cooperation in the One-Shot Prisoner’s Dilemma Game: Empirical Evidence From an Eye-Tracking Study

Abstract

Based on the dual-process theory, we hypothesized that cooperators in the one-shot prisoner’s dilemma game would exhibit intuitive decision-making. We also hypothesized that an experimental manipulation that may prevent intuitive cooperation (in this study, inverting the payoff matrix) would result in more protracted decision-making and thus lower cooperation rates. To examine these hypotheses, we designed an experiment using an eye-tracking device. In one condition, the outcome of mutual cooperation in the one-shot prisoner’s dilemma game was presented in the upper left-hand corner explaining the result of mutual cooperation first, as in many previous studies (control condition). To suppress the function of intuitive cooperation, we also set the inverted payoff matrix condition in which the positions of the outcomes of mutual cooperation and mutual non-cooperation in the payoff matrix were inverted, explaining the result of mutual non-cooperation first. Although our results did not show the expected differences between the two conditions, it was suggested that cooperators’ decision-making time was shorter in the control condition and that cooperators consistently paid more attention to the outcome of mutual cooperation regardless of the conditions. These results are discussed in relation to the intuitive cooperation model and the social exchange heuristic.