Greater Self-reported Health is Associated with Lower Disgust: Evidence for Individual Calibration of the Behavioral Immune System

A key theoretical component of the behavioral immune system is its functional flexibility, where an individual’s reaction to pathogenic stimuli is designed to fluctuate based on individual costs and benefits. For example, those who perceive themselves to be more vulnerable to disease or are in poorer health should react more aversely to possible pathogenic agents because of the higher costs of infection. To test this hypothesis, we collected measures of current individual health (i.e., self-reported general health and self-perceived infectibility) and three domains of disgust in two studies: an in-person sample of United States university students and a global online sample of diverse ages. We also collected and assayed saliva samples for secretory immunoglobulin A (sIgA), provided by the university students. Results showed that lower sIgA and higher perceived infectibility independently predicted higher pathogen disgust. Poor self-reported general health was associated with higher pathogen disgust in the university sample, but not in the online sample. Finally, pathogen disgust mediated the effect of perceived infectibility on behavioral avoidance motivation. Overall, our findings support the functional flexibility of the behavioral immune system, such that those who are more vulnerable to disease are more likely to respond aversely to situations with high pathogen load; however, future research should consider other contextual factors which affect the strength of this relationship between individuals and populations.