Face masks drive increased rational decision-making.

Face masks play a pivotal role in the control of respiratory diseases, such as the novel coronavirus (COVID-19). Despite their widespread use, little is known about how face masks affect human social interaction. Using unique experimental data collected early on in the pandemic, we investigate how facial occlusion by face masks alters socio-economic exchange. In a behavioral economics study ( N  = 481), individuals accepted more monetary offers and lower offer amounts when interacting with a masked versus unmasked opponent. Importantly, this effect was mainly driven by faces covered with surgical masks relative to bandana-type masks. In the first weeks of mask use during the COVID-19 pandemic, motive attributions further moderated this effect: Participants who believed that mask wearers were seeking to protect others showed the highest acceptance rates. Overall, we describe a new phenomenon, the face-mask effect on socio-economic exchange, and show that it is modulated by contextual factors.