Dehumanized perception: Failure to consider another person's mind

Social neuroscience and social psychology suggest that some social targets fail to engage mentalizing or Theory of Mind processes. This thesis examines dimensions that differentiate targets of dehumanized perception, a phenomenon characterized by failing to consider another person's mind. Previous research indexes dehumanized perception by a lack of medial prefrontal cortex (MPFC) activity above a fixation baseline because typically this area reliably activates to social targets. Dehumanized targets however reliably elicit the basic negative emotion disgust. Both results may relate to a failure to consider the mind of the other. Study 1 demonstrates that participants do not think about dehumanized targets' minds when imagining a day in their life, a result consistent with prior research on the role of the MPFC in so-called mentalizing. Study 1 also demonstrates that some social cognition and reward processing dimensions that previously have activated this brain region do differentiate dehumanized targets from other social targets. Study 2 next replicates the lack of MPFC activity over a fixation baseline to dehumanized targets. These social targets do elicit greater activity in a brain region associated with automatic appraisal of good or ill intention (amygdala) and a brain region associated with disgust (insula). MPFC activity to these social targets correlates with warmth ratings, but only when participants perceive dehumanized targets. Amygdala activity also correlates with insula activity for these social targets. In Study 3, self-report measures of perceived familiarity, similarity, and likely social interaction correlate with the unique emotional reactions to a variety of social targets. Furthermore, these ratings are inversely related to the disgust rating. This suggests that perhaps increased contact with social targets may moderate dehumanized perception. Dehumanized perception, possibly an extreme form of prejudice, relates to disgust, and apparently results from a failure to think about a social target's cognitive and emotional state.