The results of eighteen studies support the hypothesis that the holistic processing of faces is attenuated by social facts in a manner that serves the formation of cooperative, non-kin based communities. The first chapter establishes the phenomenon of Perceptual Dehumanization through demonstrating a functional link between face processing and social behavior. A multi-method array of social and perceptual techniques suggests that the holistic processing of faces is inhibited upon learning someone is a norm violator and that this inhibition of holistic processing facilitates punishment. The second chapter determines the social function of Perceptual Dehumanization. It combines past theoretical accounts of dehumanization with modern work on perceptual categorization to propose that perceptual dehumanization functions to produce indifference towards harm (as opposed to facilitating the active or passive infliction of harm). This thesis is supported by results from multiple methods, which indicate that the holistic processing of faces is inhibited for high status civil servant. Consistently, these inhibitions in holistic processing facilitate the sacrifice of these civil servants for the greater good. The third chapter establishes the cognitive mechanism through which the attenuation of holistic processing occurs. Results from both eye-tracking and exogenous manipulations of attention suggest that Perceptual Dehumanization occurs due to a shift in the gaze pattern that causes both changes in perceptual processing and social behavior. This program of research emphasizes the interdependency between human’s ability to identify faces (i.e. engage in holistic processing) and human’s ability to forge longstanding non-kin cooperative bonds; it suggests face perception is an inherently social process. More broadly it suggests combing social functionalism and cognitive structuralism may be a fruitful avenue for future research.