The Influence of Disgust on Judgments about Moral Violations

Abstract

Disgust initially developed to prevent oral incorporation of offensive substances and later functioned to also identify and respond to morally offensive actions and actors. Feeling disgusted upon exposure to someone’s behavior indicates that such behavior is morally suspect and urges avoidance and rejection of this behavior. Felt disgust is therefore thought to increase severity of judgments about moral violations. Recent research shows that experimental induction of disgust results in increased moral severity when judging moral transgressions. However, research to date does not rule out that this effect is caused by the negative affect associated with disgust. In study one, the role of disgust was compared with that of discomfort while participants rated various moral violations. Contrary to expectations, participants who experienced discomfort rated moral violations most severely. However, post hoc analyses showed that discomfort was elicited more intensely than disgust, potentially explaining its primary influence on moral judgments. In study two, the role of a disgust induction in moral decision-making was compared to that of an equally intense discomfort induction. This paradigm eliminated differences in moral judgments between the disgust and discomfort condition, but results showed that participants in the disgust condition made more severe judgments about violations of purity than of violations unrelated to purity. Given this specific role of disgust in moral decision-making about impurity, study three examined the role of its functional opposite, cleanliness. The role of cleanliness in judgments about pure and impure violations was compared to that of positive affect and disgust. Results showed that cleanliness resulted in less severe judgments. However, the participants who felt most clean made more severe judgments after controlling for positive affect. Results also showed that disgust failed to predict moral judgments after controlling for how negative participants felt. The findings from the three investigations are discussed in the context of a ‘Moral Character Model’ that accounts for similar judgments caused by different motivations by those who feel dirty and those who feel clean.