From bugs to sickness: disgust evaluation of ancestral, modern, and pandemic threats

Disgust is a fundamental emotion that evolved to protect organisms from pathogens and toxins, shaping behaviours critical for survival. This study explores how ancestral, modern, and pandemic-related visual stimuli elicit disgust. Specifically, our goal was to validate the categorisation of disgusting stimuli, evaluate the intensity of emotional responses, and determine the contribution of individual differences. A sample of 262 participants from diverse educational and professional backgrounds ranked 60 visual stimuli, including ancestral (spoiled food, bugs), modern (toxic substances, radioactivity), and pandemic-related (sneezing, masks, hospitals) categories, on perceived disgust (pictures of leaves were used as controls). They also completed assessments of pathogen, core, and moral disgust, along with pandemic-related behaviours and stress. Results revealed distinct clusters of disgust stimuli, with spoiled food evoking the strongest repulsion, while modern threats, such as pollution and radioactivity, elicited weaker disgust. Pandemic-related stimuli formed a unique category, with visible infection cues (e.g., sneezing) triggering stronger disgust than abstract cues like masks or hospital environments. The findings highlight the evolutionary roots of disgust and its adaptation to modern contexts. They underscore the need to consider cultural, individual, and situational factors in public health strategies and interventions targeting hygiene and disease prevention behaviours.