Abstract
This study examined the distinguishing physiological characteristics of the disgust reaction across different domains. According to an evolutionary analysis, disgust is a heterogeneous emotion with features that are specific to three distinct domains: pathogens, sex, and morality. Each domain is predicted to take as input information specific to the adaptive problem it evolved to solve and regulate behavior accordingly. The goal of the present study was to investigate whether there are any adaptive physiological differences associated with the disgust response across domains. Participants were asked to imagine acts that elicit pathogen, sexual, and moral disgust. It was hypothesized that there would be both quantitative and qualitative differences in the physiological reactions based on the appropriate functional outputs for the social (moral and sexual) and nonsocial (pathogen) domains. Individual differences in self-report ratings of disgust as well as the role of religiosity in regulating social disgust were also explored. Results showed significant differences in parasympathetic influences on the heart in response to the sexual stimuli but not to the other domains. Also, the self-report ratings showed that females were more sensitive than males to the sexual stimuli but not to pathogens or moral acts. These results lend further support to the dissociation between the functional domains of disgust. Correlations between levels of religiosity and both subjective ratings of fear towards pathogens and levator labii activation when viewing pathogen stimuli were found. This study provides preliminary evidence of dissociations between different domains of disgust and provides a methodological guideline which can help inform future studies of disgust. Implications of the current findings are discussed, as well as limitations of the current methodology and avenues for further exploration.