Abstract:

Third-party punishment (TPP) plays an important role in both improving cooperation and maintaining social norms. However, Cognitive Evaluation Theory suggests that TPP may also negatively affect cooperation, because TPP reduces the internal motivation of cooperative behaviors. Therefore, the influence of TPP on cooperation may have two different manifestations depending on the specific kind of activated social norms — descriptive norms (what most people actually do) or injunctive norms (what people should do). This study used two experiments to examine the influence of TPP on cooperation. Experiment 1 analyzed the effects of the two different social norms on cooperation without TPP. The subjects (120 university students) participated in a two-round Dictator Game, which used a 2 (high/low descriptive norms) by 2 (high/low injunctive norms) between-subjects design. Experiment 2 (with 300 university students) examined the influence of different TPP frequencies on cooperation. The subjects participated in a four-round Dictator Game with a third-party member who could punish both the dictator and the receiver in Round 2 and 3. In Round 3, the subjects were informed the frequency of TPP (a between-subjects factor), which were controlled by the experimenter on 10 levels ranging from 0% to 90%. The result showed that descriptive norms had a more significant influence in comparison to injunctive norms, and there was a significant interaction between the two types of norms. Descriptive norms played a more important role on cooperation when there was no punisher, whereas injunctive norms' effect on cooperation was stronger when there was a punisher. The results also implied that a low frequency of TPP could successfully increase the level of cooperation, even when the punishment sanction was removed. We also found that higher frequency of TPP reduced the internal motivation on cooperation. An explanation of these effects was that TPP could not only remind subjects of the injunctive norms but also the existence of norm violation. When the perception of norm violation increased with higher frequency of TPP, the perception of descriptive norms decreases and so do cooperative behaviors.

Key words: third-party punishment, descriptive norm, injunctive norm, cooperation