Considerable research demonstrates that people have a strong tendency to use facial appearance when forming first impressions of others' psychological traits, and that these impressions show considerable consensus across perceivers. The aim of the proposed research is to explain consensual first impressions of faces. The explanation to be tested is that social attributes revealed by the facial qualities that mark babies, fitness, or emotion are overgeneralized to people whose facial structure resembles that of babies, a particular level of fitness, or a particular emotional state. Research investigating relationships between facial qualities and trait impressions has provided indirect support for the overgeneralization hypothesis. However, the assumption that these impressions actually happen because of the overgeneralization of reactions to faces has not been tested. Connectionist modeling will be used to test the overgeneralization hypothesis. This technique may reveal whether the physical similarity between two faces is sufficient to account for similar impressions of them independent of similarities in the social or semantic implications of the faces. A series of experiments will provide facial metrics as input to standard back-propagation neural networks. Additional experiments will be conducted to determine whether human perceivers' impressions of the faces can be predicted from the responses of the networks. The proposed experiments will test the overgeneralization explanations for consensual first impressions of faces, and they will help identify the qualities that distinguish among faces that vary in emotional expression, genetic fitness, and maturity. The research will contribute to a better understanding of how people form impressions of one another, and ultimately how such impressions influence social interaction and interpersonal relationships.
