Competition makes observers remember faces as more aggressive.

People use facial appearance to predict social behavior, but can social context also influence face perception? Leveraging a link between competition and aggression, we investigated the effects of competitive interactions with confederates on participants' performance in a face reconstruction task. Participants played a game either in competition or cooperation with confederates and were then asked to create facial portraits of these confederates by arranging their component features into their best estimate of an accurate configuration. Across 2 experiments, participants who played in a competitive context reconstructed faces in a more aggressive configuration-with higher width-to-height ratios-than did participants who played cooperatively or alone. This result demonstrates that the social perception of faces is not merely a feed-forward process, but instead that the social contexts in which people interact can shape memory for faces.