Between self-interest and reciprocity: the social bright side of self-control failure.

Despite the importance of reciprocity in many areas of social life, little is known about possible factors affecting it and its interplay with the self-interest motive to maximize one's own gains. In this study, we examined the role of cognitive control in reciprocal behavior to determine whether it is a deliberate and controlled act or whether the behavior is evoked automatically. In Experiment 1, depletion of cognitive control resources increased the rate of rejected unfair offers in the ultimatum game despite associated financial loss. In Experiments 2A and 2B, using 2 depletion manipulations, we extended these results and showed that depleted participants returned more money in response to highly trusting investments during the trust game. These results suggest that reciprocity considerations are actively suppressed when attempting to maximize one's own gains. When cognitive control is limited, this suppression becomes difficult, and consequently reciprocity considerations prevail.