Preschoolers' generosity increases with understanding of the affective benefits of sharing.

Research has demonstrated that sharing with others is rewarding, suggesting a proximal mechanism of humans' extraordinary tendency to engage in prosocial behavior. The current study explored the cognitive basis of the relation between generosity and happiness early in ontogeny. We demonstrate that preschool children understand the relation between generosity and happiness. Moreover, our results show that children's emotion ratings are predictive for their subsequent sharing behavior. This finding provides evidence for the theoretical claim that prosocial behavior may be related to the anticipation of positive feelings, and that this mechanism may explain early instances of generosity in preschool children.