The Walking Threat: Traits of Pathogen Avoidance, Pathogen Threat Proximity and Functional Flexibility

The threat of infection to humans is unwavering, and it is increased through social interaction, which human life is based around. This has been demonstrated through the recent SARS-CoV-2 pandemic, where social distancing was recommended to prevent the spread of the virus. Therefore, it is important to understand both the behavioral and physiological defenses that we possess against illness. However, the characteristics of the relationship between the behavioral immune system (BIS) and the physiological immune system (PIS) are still murky. This dissertation sought to better understand how the BIS considers the costs of mounting an immune response via functional flexibility with the PIS through three aims. Aim 1 was to identify predictive traits of BIS responses. This was done by correlating data from various relevant surveys and performing regressions to detect predictors across two studies. Aim 2 was to discern if social pathogen threats could elicit behavioral immune responses. Aim 3 was to determine if proximity is a moderator of functionally flexible BIS responses. These aims were met by conducting a factorial experiment utilizing confederates as pathogen threats while measuring physiological responses. Data analyses revealed that both proximity and health status contribute to a crossover interaction that produced differences in antibody secretion over time. Data analyses showed that the manipulation of health status could produce differences in observed avoidant behaviors, with groups exposed to a sickly and distant confederate expressing more behaviors. Data analyses also revealed that neuroticism and illness perception are strong correlates of the BIS. It was also found that these correlates were able to predict SARS-CoV-2 exposure. These findings allow for not only a greater understanding of functional flexibility, but also inspire better public health strategies for the management of infectious disease spread.