The impact of facial attractiveness and alleged personality traits on fairness decisions in the ultimatum game: Evidence from ERPs

In the mind of the beholder the personality and facial attractiveness of others are interrelated. However, how these specific properties are processed in the neurocognitive system and interact with each other while economic decisions are made is not well understood. Here, we combined the ultimatum game with EEG technology, to investigate how alleged personality traits and the perceived facial attractiveness of proposers of fair and unfair offers influence their acceptance by the responders. As expected, acceptance rate was higher for fair than unfair allocations. Overall, responders were more likely to accept proposals from individuals with higher facial attractiveness and with more positive personality traits. In ERPs, words denoting negative personality traits elicited larger P2 components than positive trait words, and more attractive faces elicited larger LPC amplitudes. Replicating previous findings, FRN amplitudes were larger to unfair than to fair allocations. This effect was diminished if the proposer's faces were attractive or associated with positive personality traits. Hence, facial attractiveness and the valence of personality traits seem to be evaluated independently and at different time points. Subsequent decision making about unfair offers is similarly influenced by high attractiveness and positive personality of the proposer, diminishing the negative response normally elicited by "unfair" proposals, possibly due a "reward" effect. In the ERPs to the proposals the effect of positive personality and attractiveness were seen in the FRN and P300 components but for positive personality traits the effect even preceded the FRN effect. Altogether, the present results indicate that both high facial attractiveness and alleged positive personality mitigate the effects of unfair proposals, with temporally overlapping but independent neurocognitive correlates.