You cannot judge a book by its cover: Evidence from a laboratory experiment on recognizing generosity from facial information

•People cannot glean information about other-regarding preferences from facial information.•People make systematic errors when they try to identify generosity from facial information.•Those who are rated as more attractive are perceived to be more generous.•There is no actual relationship between physical attractiveness and generosity. People form first impressions of others and may make judgments about their social traits and character on the basis of facial perceptions. We implement a controlled laboratory experiment to investigate whether people can glean information about another person's other-regarding preferences from uncropped photographs of their face. To do so, we conduct a dictator game with an allocator and a recipient, and then present pairs of allocator photos to observers. Each pair portrays one relatively generous allocator and another who has demonstrated less generosity. The experimental results show that the observers cannot accurately recognize more generous allocators, but instead make systematic errors. In particular, the observers believe that allocators who are rated more attractive by others are more generous, despite there being no actual relationship between physical attractiveness and generosity.