You did not mean it: Perceived good intentions alleviate sense of unfairness

• Good intentions alleviate perceived unfairness, both on behavioral and neural levels.
• FRN and P300 represent the modulation effect of intention on fairness perception.
• P300 also exhibits the valence effect of feedback in the social domain.

Previous research has reported that feedback-related negativity (FRN) may represent the degree of perceived unfairness in the ultimatum game (UG). However, few studies have incorporated intention-related consideration in examining the neural correlates of fairness perception. To address this issue, the present study introduced an intentional UG paradigm to disentangle the effect of perceived intention from fairness concerns, using an event-related potential (ERP) analysis. Consistent with the hypothesis, the behavioral results indicated that good intention could markedly reduce rejection rates, and this intention effect was modulated by the degree of fairness, which was more prominent under unfair scenarios. Further electrophysiological results showed that, for the unfair division schemes, FRN and P300 amplitudes were significantly different between offers proposed with good intention and those with bad intention, while such discrepancies were not observed for the fair condition. In summary, converging results demonstrated that perceived intention can modulate the effect of fairness in social decision-making.