Lay beliefs in physiognomy explain overreliance on facial impression

People often rely on a person’s facial appearance when judging their character, even when more diagnostic information is available. This can lead to worse decision outcomes and appearance-based discrimination. What explains this overreliance on facial impressions? In three studies, we examine the role of lay beliefs in physiognomy—the idea that facial features are indicative of a person’s character. We find widespread endorsement of physiognomic beliefs in a representative sample of the Dutch population (Study 1, n = 2,624). Crucially, people with stronger physiognomic belief rely more on facial impressions when making trust decisions (Study 2, n = 224). They are also more confident in their ability to detect corrupt politicians based on facial photographs, but this increased confidence is not associated with superior judgment accuracy (Study 3, n = 406). In sum, our studies show that physiognomic beliefs are widespread and related to overreliance on facial impressions.