The effects of participants' sex and the facial trustworthiness of proposers on third-party decision-making in a dictator game

This study investigated the effects of participants' sex and the facial trustworthiness of proposers on third-party decision-making. Sixty-three participants participated in this study. The participant's task was to act as an interest-free third party who observed a dictator game in which proposers with either trustworthy or untrustworthy faces made offers to recipients, to evaluate the reasonableness of the offers, and to express their intentions to punish the proposers. The results showed that offers from trustworthy proposers were rated as more reasonable than offers from untrustworthy proposers. Similarly, the participants were more likely to punish untrustworthy proposers than trustworthy proposers. In addition, there was a trend that male participants punished proposers more severely than female participants when proposers made unfair offers. These results demonstrate that an individual's facial trustworthiness affects other people's judgment and decisions.