Pathogen disgust sensitivity changes according to the perceived harshness of the environment

Are cooks more disgust sensitive? Preliminary examination of the food preparation hypothesis

According to the food preparation hypothesis, sex differences in disgust sensitivity may stem from different sex roles that males and females played in our ancestral times. In current times, these differences may be reflected in varying levels of disgust sensitivity between people who frequently versus rarely engage in meal preparation, or who are versus are not professionally responsible for providing meals for others. To test this reasoning, we conducted a preregistered study with 493 individuals (55% female), with 280 of them working in the restaurant industry. Participants reported their weekly time spent on cooking-related activities and completed the Food Disgust Scale and pathogen subscale of Three Domain Disgust Scale. These measures capture specific, food-related disgust sensitivity, and generalised pathogen disgust sensitivity, respectively. We found that while time spent on cooking was not associated with disgust sensitivity, people professionally engaged in food preparation displayed higher levels of food-related disgust sensitivity. There was no effect of cooking on the generalised pathogen disgust sensitivity. Additionally, we observed sex differences in both types of disgust sensitivity and found that vegetarians exhibited lower disgust sensitivity than meat-eaters. Overall, our findings offer preliminary support for the food preparation hypothesis, and point out that the mechanisms adjusting our disgust sensitivity levels are category-specific, even within the broader pathogen disgust domain.

Pathogen disgust is associated with interpersonal bias among healthcare professionals

Background and objectives

Pathogen avoidance is a fundamental motive that shapes many aspects of human behavior including bias against groups stereotypically linked to disease (e.g. immigrants, outgroup members). This link has only been examined in convenience samples and it is unknown how pathogen avoidance processes operate in populations experiencing prolonged and heightened pathogen threat such as healthcare professionals. We examined whether healthcare professionals demonstrate the same link between pathogen disgust and intergroup bias as has been documented among the general population.

Methodology

Participants (N = 317; 210 healthcare professionals) were recruited using snowball sampling to take an online survey. Participants completed the Three Domain Disgust Scale to assess pathogen, sexual and moral disgust. Participants then rated their perceptions of a fictitious immigrant group ('Krasneeans') and the degree to which they endorsed group-binding moral values.

Results

Compared to control participants, healthcare professionals reported lower levels of pathogen disgust, but not sexual or moral disgust. However, regardless of profession, higher pathogen disgust was associated with viewing Krasneeans as less likeable and more unclean. Additionally, regardless of profession, higher pathogen disgust was associated with greater endorsement of group-binding moral values, although healthcare professionals reported greater overall endorsement of group-binding moral values than did control participants.

Conclusions and implications

Although healthcare professionals demonstrated lower levels of pathogen disgust, they nevertheless exhibited largely the same relationship between pathogen disgust and interpersonal biases as did control participants. One practical implication of this association is that pathogen avoidance motives may contribute to inequitable patient treatment in healthcare settings.

Is disgust proneness prospectively associated with influenza vaccine hesitancy and uptake?

Although various demographic and psychosocial factors have been identified as correlates of influenza vaccine hesitancy, factors that promote infectious disease avoidance, such as disgust proneness, have been rarely examined. In two large national U.S. samples (Ns = 475 and 1007), we investigated whether disgust proneness was associated with retrospective accounts of influenza vaccine uptake, influenza vaccine hesitancy, and eventual influenza vaccine uptake, while accounting for demographics and personality. Across both studies, greater age, higher education, working in healthcare, and greater disgust proneness were significantly related to greater likelihood of previously receiving an influenza vaccine. In Study 2, which was a year-long longitudinal project, disgust proneness prospectively predicted influenza vaccine hesitancy and eventual vaccine uptake during the 2020–2021 influenza season. Findings from this project expand our understanding of individual-level factors associated with influenza vaccine hesitancy and uptake, highlighting a psychological factor to be targeted in vaccine hesitancy interventions.

Control over pathogen exposure and basal immunological activity influence disgust and pathogen-avoidance motivation

Disgust is reasoned to operate in conjunction with the immune system to help protect the body from illness. However, less is known about the factors that impact the degree to which individuals invest in pathogen avoidance (disgust) versus pathogen management (prophylactic immunological activity). Here, we examine the role that one's control over pathogen contact plays in resolving such investment trade-offs, predicting that (a) those from low control environments will invest less in pathogen-avoidance strategies and (b) investment in each of these two strategies will occur in a compensatory fashion (i.e. they will be traded off with one other). Across four studies, we found support for these predictions, using a variety of manipulations and measures. By providing novel insights into how one's control over pathogen exposure influences disgust sensitivity and immune system activity, the current research poses an important contribution to the literature on disgust, pathogen avoidance, and the immune system.

Disgustingly perfect: An examination of disgust, perfectionism, and gender

High levels of disgust and perfectionism co-exist in some clinical disorders raising questions about the relationship between the two. This research evaluated socially-related and physically-related disgust in people with varying levels of perfectionism. In Study 1, 120 college students participated in a state emotion-eliciting scenario task, then completed both the Almost Perfect Scale-Revised and the Three Dimensions of Disgust Survey (TDDS). In Study 2, 380 Qualtrics users completed the scenarios, along with the TDDS and Multidimensional Perfectionist Scale. Both studies showed that state emotions differed from each other in ways that were unrelated to perfectionism. Gender differences were seen in the perfectionist groups, state disgust responses, and trait sexual disgust. However, Study 2 also showed relationships between trait perfectionism and disgust. The differing state emotional responses show that contextual interpersonal factors are highly important in disgust behaviors. Additionally, the findings suggest that gender could be important in the relationship between disgust and perfectionism.

Social distancing from foreign individuals as a disease-avoidance mechanism: Testing the assumptions of the behavioral immune system theory during the COVID-19 pandemic

Topics of prejudice, discrimination, and negative attitudes toward outgroups have attracted much attention of social scientists during the COVID-19 pandemic, as the preference for social distancing can originate from the perception of threat. One of the theoretical approaches that offers an explanation for avoidance tendencies is the behavioral immune system theory. As a motivational system that aims to identify and avoid pathogens, the behavioral immune system has been shown to be triggered by various cues of a potential disease threat (e.g., the risk of contracting a virus), which further leads to negative social consequences such as xenophobia, negative attitudes toward various social groups, and distancing tendencies. We present a correlational study (N = 588; Polish sample) that was designed to test mediational models derived from the behavioral immune system theory, using the COVID-19 pandemic as a source of natural disease threat. In serial mediation analyses we show that the perceived threat of COVID-19 translates into greater preferred social distance from foreign individuals, and that this occurs in two ways: 1) via pathogen disgust (but not sexual or moral disgust), and 2) via germ aversion (but not perceived infectability). Both pathogen disgust and germ aversion further predict general feelings toward foreign individuals, which finally determine the preferred social distance from these individuals. The results support the behavioral immune system theory as an important concept for understanding social distancing tendencies.

The evolution of disgust for pathogen detection and avoidance

The behavioral immune system posits that disgust functions to protect animals from pathogen exposure. Therefore, cues of pathogen risk should be a primary driver influencing variation in disgust. Yet, to our knowledge, neither the relationship between current pathogen risk and disgust, nor the correlation between objective and perceived pathogen risk have been addressed using ecologically valid measures in a global sample. The current article reports two studies addressing these gaps. In Study 1, we include a global sample (n = 361) and tested the influence of both perceived pathogen exposure and an objective measure of pathogen risk-local communicable infectious disease mortality rates-on individual differences in pathogen and sexual disgust sensitivities. In Study 2, we first replicate Study 1's analyses in another large sample (n = 821), targeting four countries (US, Italy, Brazil, and India); we then replaced objective and perceived pathogen risk with variables specific to the SARS-CoV-2 pandemic. In Study 1, both local infection mortality rates and perceived infection exposure predicted unique variance in pathogen and sexual disgust. In Study 2, we found that perceived infection exposure positively predicted sexual disgust, as predicted. When substituting perceived and objective SARS-CoV-2 risk in our models, perceived risk of contracting SARS-CoV-2 positively predicted pathogen and sexual disgust, and state case rates negatively predicted pathogen disgust. Further, in both studies, objective measures of risk (i.e., local infection mortality and SARS-CoV-2 rates) positively correlated with subjective measures of risk (i.e., perceived infection exposure and perceived SARS-CoV-2 risk). Ultimately, these results provide two pieces of foundational evidence for the behavioral immune system: 1) perceptions of pathogen risk accurately assay local, objective mortality risk across countries, and 2) both perceived and objective pathogen risk explain variance in disgust levels.

Disgust Sensitivity Among Women During the COVID-19 Outbreak

The emotion of disgust is suggested to be an adaptation that evolved to keep us away from sources of infection. Therefore, individuals from populations with greater pathogen stress should have a greater disgust sensitivity. However, current evidence for a positive relationship between disgust sensitivity and the intensity of infectious diseases in the environment is limited. We tested whether disgust and contamination sensitivity changed in response to the COVID-19 pandemic. Disgust was assessed in 984 women in 2017 (before pandemic) and 633 women in 2020 (during pandemic) by a set of photographs depicting sources of infection and Pathogen and Moral of Three-Domain Disgust Scale. Further, contamination sensitivity among participants in two waves was measured by Contamination Obsessions and Washing Compulsions Subscale of Padua Inventory. State anxiety was measured with the Polish adaptation of the State-Trait Anxiety Inventory (STAI) only during the second wave of data collection. Women from the COVID-19 pandemic group assessed the photographs depicting sources of infection as more disgusting, scoring higher on Padua Inventory, but lower on Moral Disgust Domain as compared to women from before the pandemic. In addition, anxiety levels during pandemic positively correlated with scores from Pathogen Disgust Domain, Padua Inventory, and the ratings of the photographs. The participants of the study scored higher in state anxiety than the norms determined for the Polish population. Summarizing, we present evidence for differences in individual levels of disgust sensitivity in relation to pathogen stress, supporting the idea that disgust evolved to serve as protection from pathogens.

Pathogen disgust sensitivity protects against infection in a high pathogen environment

Disgust is hypothesized to be an evolved emotion that functions to regulate the avoidance of pathogen-related stimuli and behaviors. Individuals with higher pathogen disgust sensitivity (PDS) are predicted to be exposed to and thus infected by fewer pathogens, though no studies have tested this directly. Furthermore, PDS is hypothesized to be locally calibrated to the types of pathogens normally encountered and the fitness-related costs and benefits of infection and avoidance. Market integration (the degree of production for and consumption from market-based economies) influences the relative costs/benefits of pathogen exposure and avoidance through sanitation, hygiene, and lifestyle changes, and is thus predicted to affect PDS. Here, we examine the function of PDS in disease avoidance, its environmental calibration, and its socioecological variation by examining associations among PDS, market-related lifestyle factors, and measures of bacterial, viral, and macroparasitic infection at the individual, household, and community levels. Data were collected among 75 participants (ages 5 to 59 y) from 28 households in three Ecuadorian Shuar communities characterized by subsistence-based lifestyles and high pathogen burden, but experiencing rapid market integration. As predicted, we found strong negative associations between PDS and biomarkers of immune response to viral/bacterial infection, and weaker associations between PDS and measures of macroparasite infection, apparently mediated by market integration-related differences. We provide support for the previously untested hypothesis that PDS is negatively associated with infection, and document variation in PDS indicative of calibration to local socioeconomic conditions. More broadly, findings highlight the importance of evolved psychological mechanisms in human health outcomes.