The Function of Revulsion: Evolutionary Perspectives on Disgust and Related Phenomena

Daniel M. T. Fessler, PhD, UCLA

Employing results from five projects, I will attempt to demonstrate that adopting a functionalist evolutionary perspective on disgust sheds light on the experience and effects of this emotion. An examination of hypothetical organ transplantation reveals that disgust is differentially associated with parts of the body in a manner that largely serves to guard against disease. Because such prophylactic behavior is potentially costly, we might expect the strength of disgust responses and related behaviors and attitudes to vary in proportion to vulnerability to infection. Female reproductive functioning offers an opportunity to investigate this thesis, as pregnancy and, to a lesser degree, the menstrual cycle are characterized by predictable changes in the ability to fight off disease. Examinations of disgust sensitivity and ethnocentric attitudes linked to disgust reveal systematic changes consistent with such compensatory prophylaxis; additional investigations of grooming behaviors and hygiene concerns suggest similar patterns. Lastly, cyclic changes in sexual disgust reveal evidence of an evolutionary process of exaptation.

The 2007 Conference