Abstract
The behavioral immune system is an evolved adaptation comprised of automatic behavioral, cognitive, and affective reactions that has allowed humans throughout evolutionary history to avoid situations that risk infection by pathogens (e.g., physical proximity to sick people). Although behavioral immune system activation may be functional by helping people avoid such situations, experiencing these automatic reactions during sexual interactions may undermine people’s evaluations of those interactions because sex requires close physical contact. We examined whether two sources of behavioral immune system activation (daily concern over contracting COVID-19 and individual differences in infection concern) undermined satisfaction with sex among 318 partnered adults in the U.S. during the COVID-19 pandemic. Participants reported individual differences in perceived infectability and then, every night for two weeks, reported their (a) daily concern about contracting COVID-19, (b) daily stress, (c) whether they had sex with their partner, and (d) their satisfaction with sex when it occurred. People’s perceived infectability moderated the association between their daily concern about contracting COVID-19 and the extent to which they enjoyed sex when it occurred, such that people higher, but not lower, in perceived infectability enjoyed sex less on days that they were more worried about contracting COVID-19 than usual. This effect was not moderated by biological sex and remained significant when controlling for biological sex, age, relationship length, and frequency of sex. Results highlight the importance of the behavioral immune system to sexual functioning and suggest a novel avenue through which the COVID-19 pandemic has disrupted relationships.