The impact of self-control depletion on social preferences in the ultimatum game

We study the interaction of different motives and decision processes in determining behavior in the ultimatum game. We rely on an ego-depletion manipulation which consumes self-control resources, thereby enhancing the influence of default reactions, or in psychological terms, automatic processes. Experimental results provide evidence that proposers make higher offers under ego depletion. Based on findings from a closely related dictator game study, which shows that depleted dictators give less than non-depleted ones, we discard the possibility that other-regarding concerns are the default mode. Instead, we conclude that depleted proposers offer more because of a strategic 'fear of rejection' of low offers, consistent with self-centered monetary concerns. For responders, ego depletion increases the likelihood to accept offers, in line with unconditional monetary concerns being more automatic than affect-influenced reactions to reject unfair offers.