The impact of partially covered faces on trust attribution, sharing resources, and perceived fairness of one’s own choices in Ultimatum Game

Covered faces have been linked with impaired emotion recognition; yet, it is entirely unexplored how an occlusion due to face masks may affect individuals’ behaviour in economic decisions. Across two studies, we explored whether partially covered faces (due to mask wearing or a horizontal black bar) and emotion displayed by the responder influence peoples’ sharing behaviour in the Ultimatum Game and the perceived fairness of one’s proposal. Study 1 showed participants were more willing to equally share their resources with a happy face (compared to a neutral one). In addition, they were more willing to make a fair proposal when the person displayed was not wearing a face mask. Our results also provide evidence that, when people had to judge how fair their proposal was, participants rated a fair proposal as fairer when responders showed happy faces without masks, while unfair proposals were rated as fairer with happy masked faces; similarly, angry faces led to fairer ratings for fair offers without masks and unfair offers with masks. Study 2 partially confirmed previous results, highlighting how a simple occlusion on the face does not have a direct effect on the proposal but moderates the effect of the displayed emotions. These findings indicate that social interactions might be affected by face occlusion, especially when it is represented by a face mask. Indeed, people might judge the same behaviour in different ways based on the fact that their counterpart has a partially covered face.