Reduced Readiness for Social Interaction as a Strategy for Pathogen Avoidance by Women in Various Stages of Pregnancy and Postpartum

The Behavioral Immune System (BIS) drives disgust-based avoidance, but its response to immunological changes during pregnancy is understudied. The Compensatory Prophylaxis Hypothesis (CPH) predicts heightened disease-avoidant social behavior in early pregnancy due to immunosuppression. We examined whether first-trimester women show reduced willingness to engage with outgroup members or individuals displaying infection signs compared to later pregnancy stages and postpartum. We also assessed moderation by perceived vulnerability to disease (PVD) and perceived COVID-19 threat. Data were collected in Poland during the COVID-19 pandemic via online surveys in two studies. In the cross-sectional Study 1 (N = 425, age 18-46, M = 29.64, SD = 5.37), pregnant participants at different stages of pregnancy assessed their willingness to engage in social contact with individuals displaying or not displaying infection cues shown in photographs, and then completed measures of PVD and Perceived Threat of COVID-19. The longitudinal Study 2 (N = 112, age 22-41, M = 30.14, SD = 4.05) employed the same procedure, administered four times-during the first, second, and third trimesters, and postpartum. Findings did not support CPH. Social avoidance was unrelated to the pregnancy stage but significantly associated with PVD and COVID-19 threat. Results underscore the situational and individual flexibility of BIS responses.