Year: 2020
Type: dissertation
Abstract: How do people detect whether someone else poses an infection risk? Over the course of evolutionary time, humans evolved sophisticated physical and psychological machinery for detecting and reducing fitness costs associated with infectious pathogens. Whereas the physical immune system evolved to detect invasive pathogens within the body and eliminate them, the “behavioral immune system” evolved to detect infection risks outside the body and engage cognitive, emotional, and behavioral mechanisms that serve to prevent infectious pathogens from entering the body in the first place. My dissertation research focuses on the psychological mechanisms that enable people to detect infection risks. Importantly, such mechanisms entail a sort of functional misperception of infection risks: given uncertainty in detecting infection and asymmetrical costs associated with false positive and false negative errors, the behavioral immune system perceives both objectively diagnostic infection cues as well as physically anomalous yet benign cues as indicators of infection risk. In other words, in order to avoid the high cost of ignoring a true infection risk, the behavioral immune system is biased to perceive infection risk in anomalous cues, even ones that are objectively benign. After I review this hypothesis and its empirical tests in Chapter 1, in Chapters 2 and 3 I report two series of studies—one series per chapter— designed to discover novel psychological mechanisms of the behavioral immune system. In Chapter 2, I employ the Implicit Association Test to explore whether people associate infection more strongly with one benign, anomalous cue (facial disfigurement) than with another (obesity). Across four studies, I find evidence that it does. Then, in Chapter 3, I employ trait-listing, drawing, and reverse correlation methods to estimate how people mentally represent infected others. I find that people list traits and draw pictures of infected people with mostly infection cues. But when people complete a reverse correlation task, they generate infected people with a mixture of threat cues. I conclude my dissertation with future directions for behavioral immune system research.
Author: Nicholas M. Michalak
Language: English
Subfield: Experimental and Cognitive Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W3166862758