Infection Breeds Reticence

Abstract

Social living brings humans great rewards, but also associated dangers, such as increased risk of infection from others. Although the body’s immune system is integral to combating disease, it is physiologically costly. Less costly are evolved mechanisms for promoting avoidance of people who are potentially infectious, such as perceiving oneself as less social and increasing the tendency to make avoidant movements. In Experiment 1, exposure to a disease prime led participants to rate themselves as less extraverted than did exposure to a control prime, and led participants high in perceived vulnerability to disease (PVD) to rate themselves as less agreeable and less open to experience than did exposure to a control prime. In Experiment 2, a disease prime facilitated avoidant tendencies in arm movements when participants viewed photographs of faces, especially for participants high in PVD. Together, these findings reveal functional changes in perception and behavior that would serve to promote avoidance of potentially infectious individuals.