Because pathogens have posed persistent threats to people (and other species) throughout history, evolution has produced behavioral and psychological mechanisms aimed at avoiding pathogens. One mechanism may involve avoidance of others who possess heuristic cues to disease. Past research suggests that, when concerns about pathogens are salient, people tend to categorize such targets (e.g., elderly targets, racial outgroup members) as outgroup members. In light of the recent debate regarding links between pathogen avoidance and intergroup biases, we conducted a preregistered replication of Makhanova et al. (2015) to examine whether chronic and situationally activated pathogen concerns interact to predict biased outgroup categorization of social targets. The current findings replicated part but not all of the pattern observed in the original study. Consistent with the original study, there was a three-way interaction between individual differences in germ aversion, an experimental manipulation of pathogen threat, and type of social target, such that the manipulation affected the categorization of elderly targets among participants low in germ aversion but not participants high in germ aversion. However, unlike the original study, no synergistic effects of target age and race were observed. Considered together, findings bolster support for the overall hypothesis that pathogen threat is associated with biased social categorization of targets displaying heuristic cues to disease.
Public Significance StatementWhen people are concerned about disease, they engage in a variety of strategies that help them avoid contact with potential sources of pathogens, including other people. The current research replicates a previous study and shows that one cognitive strategy may be to categorize other people who may harbor pathogens as belonging to a different group than oneself (rather than the same group). Even people who are not typically concerned about disease demonstrated biased social categorization when they were reminded about the threat of a new disease.