The influence of third-party's power on multi-player fairness decision-making

People's fairness decision-making depends not only on whether they themselves are treated fairly, but also on their consideration of other members of society. Our study employed the modified three-person ultimatum game and combined it with computational modeling methods to investigate the influence of third-party's decision making power (powerless vs. power) on multi-player fairness decision-making. Our results indicated that participants exhibited varying degrees of inequity aversion to different players. The computational modeling results showed that people enforced the fairness norm when the third party was powerless, and enforced both the fairness norm and the social comparison norm when the third party had power. Moreover, the diffusion of responsibility might attenuate punishment to norm violations in the presence of power third party. This study shed light on the influence of third party's power and improved the inequity aversion theory in multi-player context, and may contribute to promoting cooperation and norm compliance behavior.