Disgust may not be a straightforward extension of the immune system’s aversion to harmful substances, but rather “a psychological nebula, lacking definite boundaries, discrete internal structure, or a single center of gravity,” says psychologist Nina Strohminger.Photograph by Star Stock / Flickr
Nina Strohminger, perhaps not unlike many fans of raunchy comedies and horror flicks, is drawn to disgust. The University of Pennsylvania psychologist has written extensively on the feeling of being grossed out, and where it comes from. The dominant idea, developed by Paul Rozin and April Fallon, is that disgust evolved adaptively from an oral revulsion to biologically harmful substances, like rotten food and bodily waste. The emotion subsequently crept into the social arena, they claimed, as we became revolted by abnormal and licentious behavior. Moral repugnance arose as a result, which retains little if any connection to the biological origins of disgust. It’s “like a parfait,” Strohminger says. “It started out as one thing and things kept getting added on as it developed.”