Pathogen disgust requires no defense: a response to Shook, Terrizzi, Clay, & Oosterhoff (2015)

What Role Does Pathogen-Avoidance Psychology Play in Pandemics?

A substantial body of research has illuminated psychological adaptations motivating pathogen avoidance, mechanisms collectively known as the behavioral immune system. Can knowledge about these mechanisms inform how people respond to widespread disease outbreaks, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [coronavirus disease 2019 (COVID-19)] pandemic? We review evidence suggesting that the evolutionary history of the behavioral immune system, and the cues that activate it, are distinct in many ways from modern human experiences with pandemics. Moreover, the behaviors engaged by this system may have limited utility for combating pandemic diseases like COVID-19. A better understanding of the points of distinction and points of overlap between our evolved pathogen-avoidance psychology and responses to pandemics may help us realize a more precise and intervention-ready science.

Capturing Fluctuations in Pathogen Avoidance: the Situational Pathogen Avoidance Scale

Pathogen avoidance is an important motive underlying human behavior and is associated with numerous psychological processes—including biases against social groups heuristically associated with illness. Although there are reliable measurement scales to assess chronic dispositional levels of pathogen avoidance, no measurement scale currently exists to directly assess moment-to-moment fluctuations in pathogen avoidance. This paper presents the Situational Pathogen Avoidance (SPA) scale, which assesses situational variability in pathogen avoidance, especially as it pertains to avoidance of social stimuli. Across six studies, we demonstrate the reliability and validity of the SPA scale, show that the scale is influenced by situational activation of pathogen avoidance motives, and demonstrate that it mediates the association between pathogen avoidance motives (both chronic and situational) and social biases against obese and foreign targets. The SPA scale provides a valuable measurement tool for researchers who study pathogen avoidance and to those who study social biases more generally.

Generalized or Origin-Specific Out-Group Prejudice?: The Role of Temporary and Chronic Pathogen-Avoidance Motivation in Intergroup Relations

Researchers have proposed that intergroup prejudice is partially caused by behavioral immune system mechanisms. Across four studies (total N = 1,849), we used both experimental (pathogen priming) and individual differences (pathogen disgust sensitivity [PDS]) approaches to test whether the behavioral immune system influences prejudice toward immigrants indiscriminately (the generalized out-group prejudice hypothesis) or specifically toward immigrants from a pathogen-rich ecology (the origin-specific out-group prejudice hypothesis). Internal meta-analyses lend some support to both hypotheses. At the experimental level, pathogen primes had no effect on attitudes toward origin-unspecified immigrants or immigrants from a pathogen-rich ecology. At the individual differences level, PDS has a unique negative effect on comfort with immigrants from pathogen-rich ecologies but not on comfort with immigrants from unspecified ecologies. However, pathogen disgust sensitivity was negatively related to the decision to allow entry to both origin-unspecified immigrants and immigrants from a pathogen-rich ecology.

Sexual Disgust Trumps Pathogen Disgust in Predicting Voter Behavior During the 2016 U.S. Presidential Election

Why is disgust sensitivity associated with socially conservative political views? Is it because socially conservative ideologies mitigate the risks of infectious disease, whether by promoting out-group avoidance or by reinforcing norms that sustain antipathogenic practices? Or might it be because socially conservative ideologies promote moral standards that advance a long-term, as opposed to a short-term, sexual strategy? Recent attempts to test these two explanations have yielded differing results and conflicting interpretations. Here, we contribute to the literature by examining the relationship between disgust sensitivity and political orientation, political party affiliation, and an often overlooked outcome-actual voter behavior. We focus on voter behavior and affiliation for the 2016 U.S. presidential election to determine whether pathogen or sexual disgust better predicts socially conservative ideology. Although many prominent aspects of Donald Trump's campaign-particularly his anti-foreign message-align with the pathogen-avoidance model of conservatism, we found that pathogen-related disgust sensitivity exerted no influence on political ideology, political party affiliation, or voter behavior, after controlling for sexual disgust sensitivity. In contrast, sexual disgust sensitivity was associated with increased odds of voting for Donald Trump versus each other major presidential candidate, as well as with increased odds of affiliating with the Republican versus the Democratic or Libertarian parties. In fact, for every unit increase in sexual disgust sensitivity, the odds of a participant voting for Trump versus Clinton increased by approximately 30%. It seems, then, that sexual disgust trumps pathogen disgust in predicting socially conservative voting behavior.

The wolf will live with the lamb

Maestripieri et al. pit evolutionary psychology against social psychological and economic perspectives in a winner-take-all empirical battle. In doing so, they risk positioning evolutionary psychology as an antagonistic subdisciplinary enterprise. We worry that such a framing may exacerbate tensions between “competing” scientific perspectives and limit evolutionary psychology's potential to serve as a unifying core theory.

Distrust As a Disease Avoidance Strategy: Individual Differences in Disgust Sensitivity Regulate Generalized Social Trust

Throughout human evolutionary history, cooperative contact with others has been fundamental for human survival. At the same time, social contact has been a source of threats. In this article, we focus on one particular viable threat, communicable disease, and investigate how motivations to avoid pathogens influence people's propensity to interact and cooperate with others, as measured by individual differences in generalized social trust. While extant studies on pathogen avoidance have argued that such motivations should prompt people to avoid interactions with outgroups specifically, we argue that these motivations should prompt people to avoid others more broadly. Empirically, we utilize two convenience samples and a large nationally representative sample of US citizens to demonstrate the existence of a robust and replicable effect of individual differences in pathogen disgust sensitivity on generalized social trust. We furthermore compare the effects of pathogen disgust sensitivity on generalized social trust and outgroup prejudice and explore whether generalized social trust to some extent constitutes a pathway between pathogen avoidance motivations and prejudice.