Situational factors can increase people\'s vulnerability to intergroup bias, including prejudicial attitudes, negative stereotyping, and discrimination. We proposed that increases in inflammatory activity that coincide with acute illness may represent a hitherto unstudied situational factor that increases intergroup bias. The current study experimentally manipulated increases in inflammatory activity by administering the seasonal influenza vaccine or a saline placebo. We quantified inflammatory activity by assessing change in salivary pro-inflammatory cytokines and assessed intergroup bias using a resume evaluation task and self-reported ethnocentrism. Primary analyses focused on a subsample of 117 participants who provided high quality data; robustness analyses included various permutations of lower quality participants. Findings revealed that changes in the cytokine interleukin-1β (IL-1β) in response to the vaccine were associated with greater intergroup bias. Among participants who received the vaccine, IL-1β change was negatively associated with evaluation of a Latina (but not a White woman) applicant\'s competency and recommended starting salary. Moreover, IL-1β change was positively associated with ethnocentrism. Overall, results provide support for the hypothesis that acute illness, via the mechanistic role of inflammatory cytokines, affects social cognition in ways that can increase intergroup bias.

The emotion of disgust protects individuals against pathogens, and it has been found to be elevated during pregnancy. Physiological mechanisms discussed in relation to these changes include immune markers and progesterone levels. This study aimed to assess the association between steroids and disgust sensitivity in pregnancy. Using a prospective longitudinal design, we analyzed blood serum steroid concentrations and measured disgust sensitivity via text-based questionnaires in a sample of 179 pregnant women during their first and third trimesters. We found positive correlations between disgust sensitivity and the levels of C19 steroids (including testosterone) and its precursors in the Δ5 pathway (androstenediol, DHEA, and their sulfates) and the Δ4 pathway (androstenedione). Additionally, positive correlations were observed with 5α/β-reduced C19 steroid metabolites in both trimesters. In the first trimester, disgust sensitivity was positively associated with 17-hydroxypregnanolone and with some estrogens. In the third trimester, positive associations were observed with cortisol and immunoprotective Δ5 C19 7α/β-hydroxy-steroids. Our findings show that disgust sensitivity is positively correlated with immunomodulatory steroids, and in the third trimester, with steroids which may be related to potential maternal-anxiety-related symptoms. This study highlights the complex relationship between hormonal changes and disgust sensitivity during pregnancy.

UNASSIGNED: Disgust sensitivity to body odors plays a role in a set of psychological mechanisms supposedly evolved to avoid pathogens. To assess individual differences in body odor disgust, we previously developed the body odor disgust scale (BODS) and validated it in English. The BODS presents six scenarios where disgust could be evoked by smells coming from an internal source and an external source. The present study aimed to validate the BODS in the Italian population and to find further evidence for its structural, construct, and criterion validity.
UNASSIGNED: We used two large samples (N = 1,050, F = 527; and N = 402, F = 203, respectively) that were representative of the Italian population for sex and age.
UNASSIGNED: Across these two studies, we confirmed the hypothesized bifactor structure, with all the items loading onto a general body odor disgust sensitivity factor, and on two specific factors related to the internal structure. In terms of construct validity, we found that the BODS converged with pathogen disgust sensitivity of the three-domain disgust scale (TDDS) but was distinct from a general propensity to experience negative emotions. The BODS showed criterion validity in predicting the behavioral intentions toward COVID-19 avoidance behavior, although it did not seem to be incrementally valid when compared to the TDDS pathogen subscale. We also established scalar measurement invariance of the BODS regarding gender and found that women display higher levels of BODS.
UNASSIGNED: Results from the Italian version of the BODS indicate its structural, construct, nomological and criterion validity. Furthermore, our result on sex differences in disgust sensitivity are consistent with previous literature, and we discuss them in the broader context of cross-cultural and primate findings that points toward a possible evolutionary explanation of this difference.

A considerable amount of research has revealed that there exists an evolutionary mismatch between ancestral environments and conditions following the rise of agriculture regarding the contact between humans and animal reservoirs of infectious diseases. Based on this evolutionary mismatch framework, we examined whether visual attention exhibits adaptive attunement toward animal targets\' pathogenicity. Consistent with our predictions, faces bearing heuristic infection cues held attention to a greater extent than did animal vectors of zoonotic infectious diseases. Moreover, the results indicated that attention showed a specialized vigilance toward processing facial cues connoting the presence of infectious diseases, whereas it was allocated comparably between animal disease vectors and disease-irrelevant animals. On the other hand, the pathogen salience manipulation employed to amplify the participants\' contextual-level anti-pathogen motives did not moderate the selective allocation of attentional resources. The fact that visual attention seems poorly equipped to detect and encode animals\' zoonotic transmission risk supports the idea that our evolved disease avoidance mechanisms might have limited effectiveness in combating global outbreaks originating from zoonotic emerging infectious diseases.

Here, we introduce the EMPH special issue on Evolutionary and Biopsychosocial Perspectives on Sickness Communication. This Commentary provides an overview of each article and places them in the wider context of sickness as a social phenomenon with verbal and nonverbal signals. This Commentary, and the special issue, in general, calls for greater attention to these signals that can affect pathogen transmission and may be at the evolutionary root of our caregiving systems and behaviours.

While analysis of the impact of threatening events has moved from bit player to center stage in political science in recent decades, the phenomenon of pandemic threat is widely neglected in terms of a systematic research agenda. Tying together insights from the behavioral immune system hypothesis and standard political science models of emotional processing, we evaluate whether exposure to the COVID-19 pandemic threat is related to authoritarian attitudes and which emotions do the work. Using 12 samples with over 12,000 respondents from six European countries at two time points (2020 and 2021), we argue that pandemic threats can generate disgust, anger, and fear. Our analyses indicate that exposure to the COVID-19 pandemic threat particularly activates fear, which in turn is linked to authoritarian attitudes.

Women may be more susceptible to infections in the luteal phase, supposedly as a consequence of the hormone progesterone and its immunosuppressive action. While immunosuppression may be important for successful oocyte implantation and pregnancy, it makes women more vulnerable to pathogens. According to theory, to compensate for reduced immunocompetence, women in the luteal phase exhibit proactive behavioral responses, such as disgust and avoidance of disease-associated stimuli, to minimize contagion risk. However, previous studies yielded inconsistent results, and did not account for accompanying proactive immune responses, like the increase of secretory immunoglobin A (sIgA). Here, we assessed the proactive immune response and feelings of disgust associated with disease cues in the comparison of 61 woman with a natural menstrual cycle (31 in the follicular and 30 in the luteal phase) and 20 women taking hormonal contraception (HC). Women rated disease vulnerability and disgust propensity, watched a video displaying people with respiratory symptoms, which was evaluated for its disgust-evoking potential and contagiousness, and provided saliva samples for hormone and sIgA analysis. Women with HC reported a heightened vulnerability to disease compared to naturally cycling women, whereas both the feeling of disgust and the sIgA increase elicited by the disease video were similar across groups, regardless of progesterone. We found a u-shaped relationship between progesterone and baseline sIgA in naturally cycling women, with its nadir during ovulation. Overall, our data do not support a compensatory relationship between the proposed progesterone-induced immunosuppression and heightened disgust or a proactive sIgA response.

Infectious disease outbreaks are expected to predict support for conservative policies. However, earlier studies (January-June, 2020) reached conflicting findings regarding the association between COVID-19 threat and policy preferences in the United States. We revisit this issue by analyzing five nationally representative surveys conducted during the relatively severe periods of the pandemic (August 2020-December, 2020; total N = 82,753). Using Bayesian inference, we find strong evidence that subjective (e.g., fear of infection and pandemic outrage) but not objective (e.g., local cases and deaths) threat predicted support for liberal policies (e.g., immigration and universal health care). Meta-analyses revealed that the estimates depend on the type of subjective (.05 ≥ r ≤ .60) or objective (.00 ≥ r ≤ .14) COVID-19 threat. We propose an emotion-mediated dual-process model of pathogen management suggesting that infectious disease outbreaks activate both avoidance and caregiving motives that translate, respectively, into support for right-wing and left-wing policies.

Behavioral avoidance of parasites is a widespread strategy among animal hosts and in human public health. Avoidance has repercussions for both individual and population-level infection risk. Although most cases of parasite avoidance are viewed as adaptive, there is little evidence that the basic assumptions of evolution by natural selection are met. This study addresses this gap by testing whether there is a heritable variation in parasite avoidance behavior. We quantified behavioral avoidance of the bacterial parasite Serratia marcescens for 12 strains of the nematode host Caenorhabditis elegans. We found that these strains varied in their magnitude of avoidance, and we estimated the broad-sense heritability of this behavior to be in the range of 11%-26%. We then asked whether avoidance carries a constitutive fitness cost. We did not find evidence of one. Rather, strains with higher avoidance had higher fitness, measured as population growth rate. Together, these results direct future theoretical and empirical work to identify the forces maintaining genetic variation in parasite avoidance.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.