What Role Does Pathogen-Avoidance Psychology Play in Pandemics?

Italian validation of the body odor disgust scale

Introduction

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.

Methods

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.

Results

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.

Discussion

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.

Visual attention is not attuned to non-human animal targets' pathogenicity: an evolutionary mismatch perspective

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.

Taking Stock and Looking Forward to the Future of Pathogen Politics in Light of New Insights and Recommendations: COVID-19 Threat Was Meaningfully Associated With Support for Liberal Policies in the United States

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.

Family support during childhood as a predictor of mate retention and kin care in adults during the COVID-19 pandemic in Brazil: an exploratory study

Introduction

Experiences during development help to explain behavior expression in adulthood.

Aims

In this study, we explored how unpredictability and harshness experienced during childhood may have impacted the occurrence of reproductive milestones in adulthood and the expression of fundamental motives related to self-protection, disease avoidance, mate seeking, mate retention, and kin care (children/family) during the pandemic.

Methods

This was an exploratory study with 438 participants. Through the administration of online questionnaires, participants were assessed and categorized based on their childhood experiences, resulting in three groups: low unpredictability, high unpredictability with family support, and high unpredictability without family support.

Results

We found that family support experienced during childhood predicts a slow life-history strategy. This involves an emphasis on growth and parenting efforts at the expense reproduction and was relevant even for participants who faced financial unpredictability. During the pandemic, we also observed that mate retention and kin care (family) motives were predominant among individuals who had greater family support during childhood.

Discussion

Overall, the findings suggest that unpredictability experienced during childhood is crucial for the development of life-history strategies and the manifestation of fundamental motives in adulthood.

Exploring changes in violence across two waves of the COVID-19 pandemic in Richmond, VA

The first wave of the COVID-19 pandemic carried with it an increase in violence in the United States and abroad. The proportion of violence cases involving firearms also increased during this time, yet little research has examined these effects using data from the second wave of COVID infections. Explanations for these documented increases in gun violence put forward by scholars include increased firearm purchases, alcohol consumption, unemployment, and organized crime activity. The current work examined these trends in Richmond, VA. We collected data on patients (N = 1744) presenting with violent injuries from 2018 to 2022 from the emergency department of a Level-1 Trauma Center in Richmond, VA. Data were coded on the basis of whether they presented before the pandemic, during the first wave, or during the second wave. Logistic binomial regressions revealed that the risk of gunshot wounds increased by 32% during the first wave and 44% during the second wave, relative to the pre-COVID period, but that the increase between the first and second wave was not significant. These findings held after controlling for victim age, race, sex, and injury severity. Further analyses revealed that these effects were specific to violent injury, as we found no increase in firearm use among self-injury cases. The heightened violence reported during the COVID-19 pandemic was also observed in Richmond, VA. Gun violence in particular increased over time as other forms of violence (i.e., assaults, stabbings, and self-harm) decreased.

Awareness, Attitude, and Knowledge Among the Healthcare Workers in China at the Onset of the Oversea Monkeypox Outbreak

BACKGROUND

The outbreak of monkeypox in several nonendemic countries has been reported since May 2022. In the context of the COVID-19 pandemic, it is important to examine how healthcare workers (HCWs) respond to the monkeypox epidemic. Having been involved in the fight against COVID-19 resurgence for nearly 3 years, how HCWs in China respond to the oversea monkeypox outbreak remains unclear.

OBJECTIVE

To investigate the awareness, perceived risk, attitude and knowledge about monkeypox among HCWs in China.

DESIGN

A cross-sectional survey.

PARTICIPANTS

Physicians and nurses from 13 hospitals in Suizhou, China, were contacted through membership of the Physicians' and Nurses' Association.

MAIN MEASURES

Responses regarding their awareness, risk perception, attitude, behavior, and knowledge about the outbreak of monkeypox were collected anonymously during the second month of the outbreak between 15 and 21 June 2022.

KEY RESULTS

Of the 395 physician and 1793 nurse respondents, most had heard of the oversea monkeypox outbreak (physicians 93%, nurses 88%). More than 30% thought there existed an infection risk for themselves or family members (physicians 42%, nurses 32%). Most agreed that HCWs should pay attention to the outbreak (physicians 98%, nurses 98%). More than half had actively sought expertise (physicians 62%, nurses 52%). Approximately half believed that monkeypox may be transmitted through sexual activity or respiratory droplets, or from mother to fetus in utero (physicians 50%, 62%, 55%; nurses 40%, 60%, and 48%, respectively). Some believed that mask-wearing, hand-washing, and glove-wearing can prevent monkeypox transmission (physicians 78%, 89%, 83%; nurses 77%, 86%, 76%, respectively).

CONCLUSIONS

This study identified high awareness, high perceived risk, and pro-prevention attitudes among HCWs in China at the onset of the oversea multi-country monkeypox outbreak, but low levels of monkeypox-related knowledge. Immediate efforts are needed to fill in their knowledge gap, particularly regarding the transmission routes and prevention measures.

The COVID-19 pandemic and seeking information about condoms online: an infodemiology approach

Objectives: As condoms are effective tools for pathogen-avoidance in sexual intercourse, seeking information about condoms online may be a reactive response to the COVID-19 according to the behavioral immune system theory.Design: Taking an infodemiology perspective, this research employed multilevel analyses to examine how COVID-19 online query data (i.e., Google topic search terms Coronavirus and COVID-19) and coronavirus epidemiological data (i.e., COVID-19 cases per million and case fatality rate) would predict condom information seeking behavior online (i.e., Google topic search term Condom) throughout the pandemic across American states (Study 1) and 102 countries/territories (Study 2), after accounting for death-thought accessibility (i.e., illness-related searches), interest in birth control (i.e., birth-control-related searches), COVID-19 control policy, stay at home behavior, season, religious holidays, yearly trends, autocorrelation, and contextual variables such as HIV prevalence rate and socioeconomic development indicators (GINI index, urbanization, etc.).Results: When there were high levels of COVID-19 concerns in cyberspace in a given week, search volume for condoms increased from the previous week across American states and different countries/territories. By contrast, the effect of actual coronavirus threat was non-significant.Conclusion: Seeking information about condoms online could be a reactive response to high levels of COVID-19 concerns across different populations.

Political Attitudes and Disease Threat: Regional Pathogen Stress Is Associated With Conservative Ideology Only for Older Individuals

What environmental factors are associated with individual differences in political ideology, and do such associations change over time? We examine whether reductions in pathogen prevalence in U.S. states over the past 60 years are associated with reduced associations between parasite stress and conservatism. We report a positive association between infection levels and conservative ideology in the United States during the 1960s and 1970s. However, this correlation reduces from the 1980s onwards. These results suggest that the ecological influence of infectious diseases may be larger for older people who grew up (or whose parents grew up) during earlier time periods. We test this hypothesis by analyzing the political affiliation of 45,000 Facebook users, and find a positive association between self-reported political affiliation and regional pathogen stress for older (>40 years) but not younger individuals. It is concluded that the influence of environmental pathogen stress on ideology may have reduced over time.

COVID-19 vaccination and the behavioral immune system: The newcomer and the old friend get along in preventing infection

Despite its old evolutionary history and emotional relevance, the behavioral immune system is one of the less studied individual predictors of vaccine uptake. To fill the gap, we conducted a large online study (2072 participants) during the spring 2022 when the great majority of the Italian population had already received at least one dose of the COVID-19 vaccine. Hierarchical binary logistic regression showed that, after controlling for the confounding effects of demographic and personality factors, there was a significant and positive association between pathogen disgust sensitivity and COVID-19 vaccine uptake (OR, 1.68; 95% CI, 1.42-1.99). The likelihood of being vaccinated for a participant with the highest possible score on the PVD Germ Aversion scale was approximately 12 times higher than the likelihood for a participant with the lowest possible score. Public health messaging could leverage the activation of the behavioral immune system as an emotional driver of vaccine uptake.

Coronavirus-Related Searches on the Internet Predict COVID-19 Vaccination Rates in the Real World: A Behavioral Immune System Perspective

According to the smoke detector and functional flexibility principles of human behavioral immune system (BIS), the exposure to COVID-19 cues could motivate vaccine uptake. Using the tool of Google Trends, we tested that coronavirus-related searches-which assessed natural exposure to COVID-19 cues-would positively predict actual vaccination rates. As expected, coronavirus-related searches positively and significantly predicted vaccination rates in the United States (Study 1a) and across the globe (Study 2a) after accounting for a range of covariates. The stationary time series analyses with covariates and autocorrelation structure of the dependent variable confirmed that more coronavirus-related searches compared with last week indicated increases in vaccination rates compared with last week in the United States (Study 1b) and across the globe (Study 2b). With real-time web search data, psychological scientists could test their research questions in real-life settings and at a large scale to expand the ecological validity and generalizability of the findings.

Pandemic elevates sensitivity to moral disgust but not pathogen disgust

The behavioral immune system, with disgust as its motivational part, serves as the first line of defense in organisms' protection against pathogens. Laboratory studies indicate that disgust sensitivity adaptively adjusts to simulated environmental threat, but whether disgust levels similarly change in response to real-life threats, such as a pandemic, remains largely unknown. In a preregistered within-subject study, we tested whether the threat posed by the Covid-19 pandemic would lead to increased perceived disgust. The perception of threat was induced by testing during two phases of the Covid-19 pandemic (periods of high vs. low pathogen threat). We found heightened levels of moral disgust during a "wave" of the pandemic, but the effect was not observed in the domain of pathogen or sexual disgust. Moreover, the age of respondents and levels of trait anxiety were positively associated with pathogen and moral disgust, suggesting that variation in disgust sensitivity may be based chiefly on stable characteristics.

Homo medicus: The transition to meat eating increased pathogen pressure and the use of pharmacological plants in Homo

The human lineage transitioned to a more carnivorous niche 2.6 mya and evolved a large body size and slower life history, which likely increased zoonotic pathogen pressure. Evidence for this increase includes increased zoonotic infections in modern hunter-gatherers and bushmeat hunters, exceptionally low stomach pH compared to other primates, and divergence in immune-related genes. These all point to change, and probably intensification, in the infectious disease environment of Homo compared to earlier hominins and other apes. At the same time, the brain, an organ in which immune responses are constrained, began to triple in size. We propose that the combination of increased zoonotic pathogen pressure and the challenges of defending a large brain and body from pathogens in a long-lived mammal, selected for intensification of the plant-based self-medication strategies already in place in apes and other primates. In support, there is evidence of medicinal plant use by hominins in the middle Paleolithic, and all cultures today have sophisticated, plant-based medical systems, add spices to food, and regularly consume psychoactive plant substances that are harmful to helminths and other pathogens. We propose that the computational challenges of discovering effective plant-based treatments, the consequent ability to consume more energy-rich animal foods, and the reduced reliance on energetically-costly immune responses helped select for increased cognitive abilities and unique exchange relationships in Homo. In the story of human evolution, which has long emphasized hunting skills, medical skills had an equal role to play.

Behavioral and physiological sensitivity to natural sick faces

The capacity to rapidly detect and avoid sick people may be adaptive. Given that faces are reliably available, as well as rapidly detected and processed, they may provide health information that influences social interaction. Prior studies used faces that were manipulated to appear sick (e.g., editing photos, inducing inflammatory response); however, responses to naturally sick faces remain largely unexplored. We tested whether adults detected subtle cues of genuine, acute, potentially contagious illness in face photos compared to the same individuals when healthy. We tracked illness symptoms and severity with the Sickness Questionnaire and Common Cold Questionnaire. We also checked that sick and healthy photos were matched on low-level features. We found that participants (N = 109) rated sick faces, compared to healthy faces, as sicker, more dangerous, and eliciting more unpleasant feelings. Participants (N = 90) rated sick faces as more likely to be avoided, more tired, and more negative in expression than healthy faces. In a passive-viewing eye-tracking task, participants (N = 50) looked longer at healthy than sick faces, especially the eye region, suggesting people may be more drawn to healthy conspecifics. When making approach-avoidance decisions, participants (N = 112) had greater pupil dilation to sick than healthy faces, and more pupil dilation was associated with greater avoidance, suggesting elevated arousal to threat. Across all experiments, participants' behaviors correlated with the degree of sickness, as reported by the face donors, suggesting a nuanced, fine-tuned sensitivity. Together, these findings suggest that humans may detect subtle threats of contagion from sick faces, which may facilitate illness avoidance. By better understanding how humans naturally avoid illness in conspecifics, we may identify what information is used and ultimately improve public health.

A multiscale modeling framework to study the interdependence of brain, behavior, and pandemic

A major constraint of the behavioral epidemiological models is the assumption that human behavior is static; however, it is highly dynamic, especially in uncertain circumstances during a pandemic. To incorporate the dynamicity of human nature in the existing epidemiological models, we propose a population-wide multi-time-scale theoretical framework that assimilates neuronal plasticity as the basis of altering human emotions and behavior. For that, variable connection weights between different brain regions and their firing frequencies are coupled with a compartmental susceptible-infected-recovered model to incorporate the intrinsic dynamicity in the contact transmission rate ( β ). As an illustration, a model of fear conditioning in conjunction with awareness campaigns is developed and simulated. Results indicate that in the presence of fear conditioning, there exists an optimum duration of daily broadcast time during which awareness campaigns are most effective in mitigating the pandemic. Further, global sensitivity analysis using the Morris method highlighted that the learning rate and firing frequency of the unconditioned circuit are crucial regulators in modulating the emergent pandemic waves. The present study makes a case for incorporating neuronal dynamics as a basis of behavioral immune response and has further implications in designing awareness campaigns.

Does the threat of COVID-19 modulate automatic imitation?

The tendency to involuntarily imitate the actions of others (automatic imitation) can be modulated by social affiliative cues. Here, we explored whether the disruption to our social lives caused by the COVID-19 pandemic may subsequently influence automatic imitation. Three groups were initially presented a sentence comprehension task that featured either neutral (control), safe or unsafe primes to COVID-19 infection. They then completed an automatic imitation task, where a numeric cue was presented alongside apparent motion of an index or middle finger, which was either compatible or incompatible with the required response. Reaction times were longer for the incompatible compared to compatible trials, and thus demonstrated automatic imitation. However, there was no influence of the primes indicating that automatic imitation was unaffected by the risk of COVID-19. The potential theoretical explanations and practical implications of pathogen avoidance and social bonding incentives are discussed with reference to pandemic events.

Disgust sensitivity in early pregnancy as a response to high pathogen risk

Introduction

Considered a part of the behavioral immune system (BIS), disgust sensitivity is expected to be adjusting as a response to the actual level of the environmental health risks.

Methods

In this preregistered study, we tested the hypothesis that disgust sensitivity would be higher during the COVID-19 pandemic compared to the pre-pandemic period in pregnant women. In this between-subject study with a longitudinal trend design, we administered the Disgust Scale-Revised to 200 pregnant women before the pandemic and to 350 pregnant women during the pandemic.

Results

We found a small but significant effect of the pandemic on disgust sensitivity, such that higher disgust sensitivity was found in women pregnant during the pandemic. This effect was stronger in primiparae, however, the interaction between parity and the pandemic period was not significant. Disgust sensitivity decreased with age. No differences in terms of nausea and vomiting were found between the women pregnant before and during the pandemic.

Discussion

Our findings indicate that although BIS is presumed to function as a complex mechanism to prevent health-threatening behaviors, its activation in pregnant women during the COVID-19 pandemic is rather weak.

Explicitness, disgust, and safe sex behavior: A message experiment with U.S. adults

Sexual health risks are challenging to communicate given the potential negative reactions of target audiences to explicit language. Grounded in research on pathogen avoidance, the current study examined the impact of varying levels of explicit language on message perceptions and safe sex behavioral intentions. U.S. adults (N = 498) were randomly assigned to view messages detailing pandemic safe sexual behavior that contained either low or high levels of explicit language. High explicit language significantly increased perceived disgust which also indirectly linked high explicit language with increased intentions to engage in safe sex behavior. Individual difference variables moderated the impact of message explicitness; dispositional hygiene disgust moderated the impact of high explicit, hygiene-focused messages on safe sex intentions. Those with relatively low levels of dispositional disgust were more positively impacted by explicit language. The results suggest the value of increased message explicitness for sexual health communication and have implications for pathogen avoidance behaviors, the behavioral immune system, and dispositional and affective forms of disgust.

Pandemic threat and authoritarian attitudes in Europe: An empirical analysis of the exposure to COVID-19

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.

The behavioral immune system in action: Psychological correlates of pathogen disgust sensitivity in healthcare professionals working in a COVID-19 hospital

The behavioral immune system includes a set of proactive mechanisms that inhibit contact with pathogens in the first place. These mechanisms offer a sort of psychological and behavioral prophylaxis against infection. The aim of this study was to assess the functionality of the behavioral immune system under conditions of strong ecological validity. Our hypothesis was that the emotional and more primitive component of the behavioral immune system (i.e. pathogen disgust sensitivity) acts as a powerful predictor of fear of infection. The sample was made up of 101 healthcare professionals working in a COVID-19 hospital when vaccination was not yet available. We conducted a hierarchical regression analysis to assess the role of germ-related disgust in modulating levels of fear. After controlling for the significant effects of depressive symptoms and exposure to people with a confirmed diagnosis of COVID-19, we found that fear of infection was more intense in those healthcare workers who reported higher levels of germ-related disgust. Fear of infection was not related to perceived infectability, an individual variable informed by more rational cognitive appraisals. These findings show that, even in healthcare workers who can take advantage of their professional knowledge and acquired skills for rational appraisals, the most primitive component of the behavioral immune system still plays a major role in eliciting fear of COVID-19. It is likely that the psychological reactions elicited by the behavioral immune system promote preventive health behaviors in modern environments as well.

COVID-19 and Memory: A Novel Contamination Effect in Memory

The Behavioral Immune System (BIS, Schaller & Park, 2011) is a defense system whose function is to protect against pathogen exposure. Memory is an important component of this system (Fernandes et al., 2017). We investigated "contamination effects" in memory in relation to COVID-19. Photographs of everyday objects were shown to adults (N = 80) in the hands of either a healthy or a contagious person who had contracted SARS-CoV-2. "Contaminated objects" were recalled better than "non-contaminated objects" suggesting that a contamination effect in memory in humans is easily acquired in the absence of apparent visual cues of disease.

Helping While Social Distancing: Pathogen Avoidance Motives Influence People's Helping Intentions during the COVID-19 Pandemic

The behavioral immune system (BIS) theory suggests that pathogen avoidance motives relate to greater behavioral avoidance against social interactions that pose potential risks of pathogen transmission. Based on the BIS theory, pathogen avoidance motives would decrease people’s helping behavior towards others. However, would pathogen avoidance motives decrease all types of helping behavior towards others during the Coronavirus disease 2019 (i.e., COVID-19) pandemic indiscriminately? In the present study, we conducted a within-subjects design to compare people’s helping intentions toward voluntary work with and without social contact. Specifically, participants (N = 1562) completed an online survey at the early stage of the COVID-19 pandemic in China measuring pathogen disgust sensitivity, state anxiety, and intentions to perform volunteer work with and without social contact. Results revealed that pathogen disgust sensitivity negatively predicted intentions to perform voluntary work with social contact yet had no influence on intentions to perform socially distanced voluntary work. Moreover, the effect of pathogen disgust sensitivity on socially distanced volunteering preference was mediated by the state anxiety people experienced during the pandemic. The findings have implications for understanding people’s helping behavior during the pandemic.

Fear of Infection and the Common Good: COVID-19 and the First Italian Lockdown

In the first quarter of 2020, Italy became one of the earliest hotspots of COVID-19 infection, and the government imposed a lockdown. During the lockdown, an online survey of 2053 adults was conducted that asked about health behaviors and about the psychological and overall impact of COVID-19. The present study is a secondary analysis of that data. We hypothesized that self-control, higher socio-economic status, existing health conditions, and fear of infection were all inversely related to actions (or intentions) that violated the lockdown (i.e., infractions). Using partial least squares structural equation modeling (PLS-SEM), we found that only the fear of infection significantly dissuaded people from violating lockdown rules. Since it is not practical or ethical to sow a fear of infection, our study indicates that enacting rules and enforcing them firmly and fairly are important tools for containing the infection. This may become more important as vaccines become more widely available and people lose their fear of infection.

"Touch Me If You Can!": Individual Differences in Disease Avoidance and Social Touch

The threat of diseases varies considerably among individuals, and it has been found to be linked to various proactive or reactive behaviors. In the present studies, we investigated the impact of individual differences in the perceived vulnerability to disease (PVD) on social touch before (Study 1) or during the coronavirus disease 2019 (COVID-19) pandemic (Study 2). We also investigated the influence of personality traits in the covariation between these two dimensions. We found that people who are the most disease-avoidant are also the most reluctant to touching or being touched by others (and this relationship holds when personality traits are taken into account). Interestingly, the association between PVD and social touch increased during the COVID-19 pandemic compared with a few months before. By showing that the fear of contamination has an association with social touch, the findings provide further evidence for the behavioral immune system ( Schaller and Park, 2011), a psychological system acting as a first line of defense against pathogens.

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.

Crowd Salience Heightens Tolerance to Healthy Facial Features

OBJECTIVE

Recent findings suggest crowd salience heightens pathogen-avoidant motives, serving to reduce individuals' infection risk through interpersonal contact. Such experiences may similarly facilitate the identification, and avoidance, of diseased conspecifics. The current experiment sought to replicate and extend previous crowding research.

METHODS

In this experiment, we primed participants at two universities with either a crowding or control experience before having them evaluate faces manipulated to appear healthy or diseased by indicating the degree to which they would want to interact with them.

RESULTS

Crowding-primed participants reported a more heightened preferences for healthy faces than control-primed participants. Additionally, crowd salience reduced aversion toward healthy faces but did not heighten aversion to diseased faces.

CONCLUSION

Results suggest crowding appears to heighten tolerance for health cues given the heightened proximal threat of infections through interpersonal contact within crowded environments. Conversely, this work extends previous findings by indicating this preference is not rooted in an aversion to cues of poor health. We frame findings from a threat management perspective in understanding how crowding fosters sensitivity toward pathogenic threats.

Effects of Pathogen-Avoidance Tendency on Infection-Prevention Behaviors and Exclusionary Attitudes toward Foreigners: A Longitudinal Study of the COVID-19 Outbreak in Japan

This study investigated the changes in public behaviors and attitudes following the spread of COVID-19 in Japan. Using a longitudinal approach that analyzes the movement of an unpredictable and real infection threat to explain and predict human behavior during the pandemic-a novel approach in behavioral immune system research-a panel survey was conducted on Japanese citizens. The results of the survey, conducted in late January, mid-February, and early March 2020, indicated that the influence of the interaction between the changes in situational infection threat and individual differences in pathogen-avoidance tendency on infection-prevention behaviors and exclusionary attitudes toward foreigners was not significant. Moreover, frequent contact with foreigners had a mitigating effect on exclusionary attitudes. The study thus provided a valuable contribution to the application of behavioral immune-system responses to problems associated with infection threats. Moreover, consideration of the aspects of adaptive reaction and social learning allowed us to observe the process of adaptive strategies in novel environments under conditions of high ecological validity and to accurately understand the psychological response to infectious disease outbreaks.

Public Perspectives on Decisions About Emergency Care Seeking for Care Unrelated to COVID-19 During the COVID-19 Pandemic

IMPORTANCE

Delaying critical care for treatable conditions owing to fear of contracting COVID-19 in the emergency department (ED) is associated with avoidable morbidity and mortality.

OBJECTIVE

To assess and quantify how people decided whether to present to the ED during the COVID-19 pandemic for care unrelated to COVID-19 using conjoint analysis, a form of trade-off analysis that examines how individuals make complex decisions.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional survey study was conducted using a nationwide sample from June 1, 2020, during the initial peak of the COVID-19 pandemic. Included participants were adults aged 18 years or older in the US who self-reported that they had not tested positive for COVID-19. Data were analyzed from July 2020 through May 2021.

EXPOSURES

Participants completed a self-administered online survey.

MAIN OUTCOMES AND MEASURES

Using a choice-based conjoint analysis survey, the relative importance was assessed for the following attributes for individuals in deciding whether to seek ED care for symptoms consistent with myocardial infarction or appendicitis: reduction in chance of dying because of ED treatment, crowdedness of ED with other patients, and chance of contracting COVID-19 in the ED. We also performed latent class analyses using conjoint data to identify distinct segments of the respondent population with similar choice patterns. Logistic regression was then used to explore whether patient sociodemographics and political affiliations were factors associated with decision-making.

RESULTS

Among 1981 individuals invited to participate, 933 respondents (47.1%) completed the survey; participants' mean (SD) age was 40.1 (13.0) years, and 491 (52.6%) were women. In latent class analyses, 158 individuals (16.9%) with symptoms of myocardial infarction and 238 individuals (25.5%) with symptoms of appendicitis prioritized avoidance of COVID-19 exposure in the ED (ie, chance of contracting COVID-19 in the ED or crowdedness of ED with other patients) over seeking appropriate care for symptoms. Having a usual source of care was a factor associated with lower odds of prioritizing avoidance of COVID-19 exposure (myocardial infarction scenario: adjusted odds ratio, 0.49 [95% CI, 0.32-0.76]; P = .001; appendicitis scenario: adjusted odds ratio, 0.57 [95% CI, 0.40-0.82]; P = .003), but most sociodemographic factors and political affiliations were not factors associated with decision-making.

CONCLUSIONS AND RELEVANCE

This study found that up to one-quarter of individuals were willing to forgo potentially life-saving ED care to avoid exposure to COVID-19. These findings suggest that health care systems and public health organizations should develop effective communications for patients and the community at large that reassure and encourage timely health care for critical needs during the ongoing COVID-19 pandemic and other scenarios.

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.

Testing the Disgust-Based Mechanism of Homonegative Attitudes in the Context of the COVID-19 Pandemic

Negative attitudes and stigmatization can originate from the perception of a disease-related threat. Following the spread of the COVID-19 pandemic, it is often suggested that incidents of discriminatory behavior are the result of defense mechanisms aimed at avoiding pathogens. According to the behavioral immune system theory, people are motivated to distance themselves from individuals who show signs of infection, or who are only heuristically associated with a disease, primarily because of the disgust they evoke. In this paper we focus on negative attitudes toward gay men and lesbians who are among social groups that have been persistently framed as "unclean." In our correlational study (N = 500 heterosexual participants; Polish sample data collected during the first COVID-19 lockdown in Poland, in March/April 2020) we tested moderation models derived from the behavioral immune system theory. Specifically, we investigated whether perceived vulnerability to disease and perceived threat of contracting COVID-19 moderate the relation between disgust and homonegativity. We found that sexual disgust (but not pathogen nor moral disgust) predicted homonegative attitudes. This effect was stronger for participants expressing higher levels of perceived vulnerability to disease but was not dependent on the perception of the COVID-19 threat. The results reaffirm previous evidence indicating a pivotal role of disgust in disease-avoidance mechanisms. They also point to functional flexibility of the behavioral immune system by demonstrating the moderating role of perceived vulnerability to disease in shaping homonegative attitudes. Finally, they show that the threat of COVID-19 does not strengthen the relationship between disgust and homonegativity.

Effects of Social Distancing During the COVID-19 Pandemic on Anxiety and Eating Behavior-A Longitudinal Study

As social animals, humans need to live in groups. This contact with conspecifics is essential for their evolution and survival. Among the recommendations to reduce transmission of the new coronavirus (SARS-CoV-2) responsible for COVID-19 are social distancing and home confinement. These measures may negatively affect the social life and, consequently, the emotional state and eating behavior of individuals. We assessed the impact of the COVID-19 pandemic on the anxiety, premenstrual symptoms, and eating behavior of young women. Data collection was conducted in person (prepandemic—from March to December 2019) and online (during the pandemic—August 2020). A total of 71 participants, average age of 21.26 years (SD = 0.41), took part in the study. Trait anxiety during the pandemic was significantly lower than in the prepandemic period. Investigation of the “anxiety/stress” symptom of the Premenstrual Symptoms Screening Tool (PSST) revealed that this symptom was more severe before the pandemic. There was a decline in the desire for sweet and fatty foods during the pandemic. However, craving for traditional foods rose significantly in the same period. Uncontrolled and emotional eating were significantly lower during the pandemic. The results suggest that the pandemic may have had a positive impact on anxiety and eating behavior of the participants, which may be due to differences between urban and rural populations and the latter living with their families. These findings are important for raising a discussion regarding the effects of the current environment on the regulation of cognitive and dietary adaptations.

Under the spell of SARS-CoV-2: A closer look at the sociopolitical dynamics

Sitting on the fine line between pathogen 'transmissibility' and 'severity', the Behavioural Immune System (BIS) is responsible for activating behaviours that minimise infection risks and maximise fitness. To achieve self-preservation, the BIS also fuels social and political attitudes. We aim to explain societal changes that may be sparked by COVID-19 by highlighting links between human evolutionary history and our psychological faculties mediated by the BIS.

Do Islanders Have a More Reactive Behavioral Immune System? Social Cognitions and Preferred Interpersonal Distances During the COVID-19 Pandemic

Insular populations have traditionally drawn a lot of attention from epidemiologists as they provide important insights regarding transmission of infectious diseases and propagation of epidemics. There are numerous historical instances where isolated populations showed high morbidity once a new virus entered the population. Building upon that and recent findings that the activation of the behavioral immune system (BIS) depends both upon one's vulnerability and environmental context, we predicted that, during the COVID-19 pandemic, place of residence (island vs. mainland) explains a significant proportion of variance in preferred interpersonal distances, animosity toward strangers, and willingness to punish those who do not adhere to COVID-19 preventive measures. With 48 populated islands, Croatia provides a fruitful testing ground for this prediction. We also opted to explore relations among BIS-related variables (pathogen disgust, germ aversion, and perceived infectability) and social cognitions in a more natural context than has previously been done. The study was conducted online, on Croatian residents, during April and May 2020. As expected, the BIS variables contributed significantly to preferred interpersonal distances, negative emotions toward strangers, and willingness to punish those who do not adhere to COVID-19 preventive measures. Furthermore, our results showed that geographical location explained a significant amount of variance in preferred social (but not personal and intimate) distances and negative emotions toward foreigners. As Croatian islands are extremely frequent travel destinations, these differences between mainlanders and islanders cannot be explained by the lack of exposure to foreigners. Additionally, we found that scores on preferred interpersonal distances, pathogen disgust, and germ aversion were significantly higher compared to those obtained in Croatian samples before the COVID-19 pandemic. Furthermore, men scored higher in perceived infectability than before the COVID-19 pandemic, and women did not, which reflects the objectively higher risk of SARS-CoV-2 for men than for women. Taken together, our results support the notion that BIS is a highly adaptive and context-dependent response system, likely more reactive in more susceptible individuals.

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.

COVID-19 Pandemic on Fire: Evolved Propensities for Nocturnal Activities as a Liability Against Epidemiological Control

Humans have been using fire for hundreds of millennia, creating an ancestral expansion toward the nocturnal niche. The new adaptive challenges faced at night were recurrent enough to amplify existing psychological variation in our species. Night-time is dangerous and mysterious, so it selects for individuals with higher tendencies for paranoia, risk-taking, and sociability (because of security in numbers). During night-time, individuals are generally tired and show decreased self-control and increased impulsive behaviors. The lower visibility during night-time favors the partial concealment of identity and opens more opportunities for disinhibition of self-interested behaviors. Indeed, individuals with an evening-oriented chronotype are more paranoid, risk-taking, extraverted, impulsive, promiscuous, and have higher antisocial personality traits. However, under some circumstances, such as respiratory pandemics, the psychobehavioral traits favored by the nocturnal niche might be counter-productive, increasing contagion rates of a disease that can evade the behavioral immune system because its disease cues are often nonexistent or mild. The eveningness epidemiological liability hypothesis presented here suggests that during the COVID-19 pandemic, the evening-oriented psychobehavioral profile can have collectively harmful consequences: there is a clash of core tendencies between the nocturnal chronotype and the recent viral transmission-mitigating safety guidelines and rules. The pandemic safety protocols disrupt much normal social activity, particularly at night when making new social contacts is desired. The SARS-CoV-2 virus is contagious even in presymptomatic and asymptomatic individuals, which enables it to mostly evade our evolved contagious disease avoidance mechanisms. A growing body of research has indirectly shown that individual traits interfering with social distancing and anti-contagion measures are related to those of the nocturnal chronotype. Indeed, some of the social contexts that have been identified as superspreading events occur at night, such as in restaurants, bars, and nightclubs. Furthermore, nocturnal environmental conditions favor the survival of the SARS-CoV-2 virus much longer than daytime conditions. We compare the eveningness epidemiological liability hypothesis with other factors related to non-compliance with pandemic safety protocols, namely sex, age, and life history. Although there is not yet a direct link between the nocturnal chronotype and non-compliance with pandemic safety protocols, security measures and future empirical research should take this crucial evolutionary mismatch and adaptive metaproblem into account, and focus on how to avoid nocturnal individuals becoming superspreaders, offering secure alternatives for nocturnal social activities.