Punishment aims to deter individuals’ selfish behaviors, but it can occasionally backfire. Some scholars have proposed promoting prosocial behaviors using punishment that communicates positive social norms because it provides additional motivation. However, it is unclear which factors affect the norm expressive function of punishment. This study proposes that third-party punishment communicates more positive normative information, and thus, promotes more prosocial behavior in observers than does second-party punishment. Using dictator games, we investigated the effects of second-party punishment compared to third-party punishment of another’s unfair sharing on observers’ norm perceptions and subsequent sharing decision-making. Two experiments consistently found that third-party punishment was more effective than second-party punishment at inducing observers’ beliefs that unfair distribution was unusual (descriptive norm) and unacceptable (injunctive norm). The altered descriptive but not injunctive norm perception further guided individuals’ own sharing behaviors. Taken together, these results suggest that third-party punishment might be better than second-party punishment at decreasing selfish behaviors by shaping individuals’ norm perceptions, especially descriptive norm perception, regarding the relevant behaviors.

Engaging in prosocial behavior is considered an effective way to increase happiness in a sustainable manner. However, there is insufficient knowledge about the conditions under which such a happiness effect occurs. From a person-activity congruence perspective, we proposed that an individual’s eudaimonic orientation moderates the effect of prosocial behavior on happiness, whereas hedonic orientation does not. For this purpose, 128 participants were assigned to play a game in which half of them were explained the benevolence impact of playing the game (the benevolence condition), and the other half played the same game without this knowledge (the control condition). Participants’ eudaimonic and hedonic orientations were assessed before the game, and their post-task happiness were measured after the game. The results showed that participants in the benevolence condition reported higher post-task positive affect than those in the control condition. Furthermore, this happiness effect was moderated by participants’ eudaimonic orientation—participants with high eudaimonic orientation reaped greater benefits from benevolence, and their hedonic orientation did not moderate the relationship between benevolence and happiness. The importance of the effect of person-activity congruence on happiness is discussed, along with the implications of these findings for sustainably pursuing happiness.