Learning to judge a book by its cover: Rapid acquisition of facial stereotypes

People are able to quickly and automatically evaluate faces on different traits, such as trustworthiness. There is a growing literature demonstrating that factors such as learning and experience play a role in shaping these judgments. In the current work, we assess the malleability of our trait evaluations by associating arbitrary facial features with trustworthy or untrustworthy behaviors. Across five studies, we demonstrate that this learning can impact trait evaluation and effectively form novel facial stereotypes, which exert effects on evaluations as strong as intrinsic facial trustworthiness. With only a brief training, participants' rapidly acquired novel facial stereotypes, which were activated automatically and early on in processing, and which biased participants' trust behavior and hiring decisions. These results suggest that our trait evaluations of faces are shaped by an implicit learning mechanism that abstracts the co-occurrence between facial features and trait-related behaviors, resulting in the creation of novel facial stereotypes.