Ensemble statistics shape face adaptation and the cheerleader effect.

When confronted with a scene of emotional faces, our brains automatically average the individual facial expressions together to create the gist of the collective emotion. Here, we tested whether this ensemble averaging could also occur for facial attractiveness, and in turn shape 2 related face perception phenomena: adaptation and the cheerleader effect. In our first 2 experiments, we showed that adaptation aftereffects could indeed be shaped by ensemble statistics; viewing an increasingly unattractive group of faces conversely increased attractiveness judgments for a subsequently presented face. Not only did group adaptation aftereffects occur, but their effects were equivalent to those observed from the morphed average face of the group, suggesting that the visual system had averaged the group together. In our last 2 experiments, we showed that viewing a target face in an increasingly unattractive group led to the target being perceived as increasingly more attractive: a "cheerleader" effect. Moreover, our results suggest that this cheerleader effect likely comprises of both a social positive effect and a contrastive process, requiring variance between the surrounding and target faces; that is, the visual system appeared incapable of boosting a target's attractiveness when all of the faces in the scene were identical. Furthermore, the mean group attractiveness ratings strongly predicted both the cheerleader effect and adaptation aftereffects, with the latter 2 also interrelated. This suggests that ensemble statistics is the common underlying process linking each of these phenomena. To be perceived as beautiful, being surrounded by unattractive friends may help. (PsycINFO Database Record (c) 2019 APA, all rights reserved).