How Does Gratitude Promote Prosocial Behavior? Developmental Differences in the Underlying Motivation1

Abstract Gratitude promotes prosocial behavior, but the developmental differences in the underlying motivation remain unclear. We investigated whether the effect of gratitude on prosocial behavior is driven by fairness or generosity motivations, and whether the underlying motivation differs by developmental stage. University students (Experiment 1) and elementary school children (Experiment 2) were assigned to either a gratitude or a neutral group. The former group recalled an event that elicited feelings of gratitude, while the latter group recalled a neutral event from their morning routine. Prosocial behavior was assessed using the three resource‐allocation tasks that can distinguish between fairness and generosity motivations. In these tasks, the participants allocated rewards to themselves and another individual. The results indicate that the effect of gratitude on prosocial behavior is driven by generosity motivation in university students (Experiment 1), while it is driven by fairness motivation in elementary school children (Experiment 2). These results reveal developmental differences in the underlying motivation for gratitude on prosocial behavior.