Abstract
Disgust is a universal emotion that helps in avoiding harmful substances. More recent research has examined moral disgust, a negative reaction to violations of norms which is said to have developed out of the primitive core disgust system. Research on disgust has shown that perceived physical disgust elevates people’s harshness evaluating morally ambiguous events. The current study aimed to test the effect of physical disgust on moral judgments and decision making by using visually disgusting images, collected from the International Affective Picture System (IAPS) and the Culpepper Disgust Image Set (C-DIS). We hypothesized that visually disgusting stimuli would elevate people’s harshness evaluating moral violation vignettes and reduce the tendencies to make unethical decisions. We also explored any differences between varying types of disgust on moral judgment. Results showed that participants made harsher judgments of moral violations and made fewer unethical decisions after viewing disgusting images than after viewing neutral images. Differences among specific types of disgust were also observed. The images involving body-envelop violation, body waste elicited the harshest moral judgments, the images involving snakes, insects, spiders, and worms came second, and the images involving corrupt food and hygiene issues (injectors, sneezing person) elicited the least harsh moral judgment. Future research could explore the fading of disgust perception over time, which was observed in the present study. To enhance ecological validity, replication with a behavioral measure of moral decision is critical. Results from the current study suggest potential application of visual disgust as a convenient and flexible method to affect immoral behavior.