The Impact of the Covid-19 Pandemic on Disgust Sensitivity

Germ aversion is a risk factor for chronic low back pain and shoulder pain under the COVID-19 pandemic: an internet-based panel study

The COVID-19 pandemic has increased germ aversion, an aversive affective response to a high likelihood of pathogen transmission. While psychological factors are associated with chronic pain, the relationship between germ aversion and chronic pain remains unexplored. This study aimed to examine the relationship between germ aversion and new-onset and prognosis of chronic pain using longitudinal data collected during the COVID-19 pandemic. We conducted web-based surveys of full-time workers at baseline and after three months. Data were collected on demographic characteristics, psychological factors, and chronic pain. Germ aversion was assessed using a modified Perceived Vulnerability to Disease scale. We analyzed responses from 1265 panelists who completed the survey twice. The prevalence of chronic low back pain (CLBP) and chronic neck and shoulder pain (CNSP) was associated with sex, short sleep duration, psychological distress, loneliness, and germ aversion. Stratified analyses showed that germ aversion was a risk factor for CLBP at three months in both individuals with and without CLBP at baseline, and for CNSP at three months in those with CNSP at baseline, even after adjustment for confounders. In conclusion, this preliminary study suggests that high germ aversion is a risk factor for CLBP and CNSP in young and middle-aged workers.

Stevenson R. Differential involvement of the senses in disgust memories

One prediction derived from the disease avoidance account of disgust is that proximal disgust cues (smells, tastes and touches) should elicit this emotion more intensely than distal disgust cues (sights and sounds). If correct, then memories of disgusting experiences should involve smelling, tasting or touching to a greater degree than seeing or hearing. Two surveys were conducted on university students to test this idea, drawing upon their naturalistic experiences. Survey 1 (N = 127) asked participants to detail their most memorable disgusting, fear-provoking, morally repulsive and yucky/gross experience, with each recollection self-rated for sensory involvement. Survey 2 (N = 89) employed the same task, but this time, participants recollected their most common disgusting, fear-provoking, morally repulsive and yucky/gross experience in the preceding week. The majority of disgusting experiences were core disgusts-i.e. related to disease/pathogen presence or stimuli. The proximal and distal sensory cues contributed equally to individuals' most memorable core disgust experiences, but the proximal senses were more involved than the distal senses in individuals' most common core disgust experiences. Further, the proximal sensory cues, as compared with the distal sensory cues, were signficantly more involved in core disgust experiences than in morally repulsive and fear-provoking experiences. The implications of these findings for a disease avoidance account of disgust, for multi-sensory disgust research, and core disgust's classification as an emotion or a drive, are discussed.

I Got it. Perceived Infectability and Germ Aversion after Covid-19 Infection

Objective

The COVID-19 pandemic has offered a unique opportunity to test evolutionary hypotheses on the functionality of the behavioral immune system. The aim of the present study was to ascertain if a previous infection with COVID-19 was associated with increased levels of perceived infectability and germ aversion. Based on the calibration hypothesis, we predicted that the activation of the behavioral immune system was greater in those participants who had been infected compared to those who reported no previous COVID-19 infection.

Method

The sample included 2072 participants who completed an online survey between March 1 and April 10, 2022 when the Italian population was facing the third wave of the COVID-19 pandemic. To measure the activation of the behavioral immune system, we used the Perceived Vulnerability to Disease (PVD) scale.

Results

Perceived infectability was significantly greater in those participants who had been infected compared to those who reported no previous COVID-19 infection but there was no significant difference between the two groups in terms of germ aversion.Conclusions Overall, our findings suggest that individual differences in the activation of the behavioral immune system were marginally affected by a personal history of COVID-19 infection. A possible explanation is that the environmental sensitivity of the behavioral immune system is tuned more on chronic disease threat (i.e., ecologies with higher pathogen load) than on situational disease threat (e.g., a pandemic or disease outbreak like the COVID-19 pandemic).

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.

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.

The psychometric properties and gender invariance of the Italian version of the Perceived Vulnerability to Disease Questionnaire (I-PVDQ) during the COVID-19 pandemic

BACKGROUND

The Perceived Vulnerability to Disease Questionnaire (PVDQ) measures beliefs associated with personal susceptibility to infectious diseases and behaviors or perceptions in the presence of potential risk of pathogen transmission. Given the onset of the Severe Acute Respiratory Syndrome Coronavirus 2 global pandemic, otherwise known as the COVID-19 pandemic, the construct being measured may function differently based on affective, behavioral, and cognitive changes along with the need to change norms and lifestyles in a global context. The present study aims to test the psychometric properties and the gender invariance of the Italian adaptation of the PVDQ to confirm that the scale can be used with Italian-speaking people, and that it functions effectively during a pandemic.

METHODS

A total of 509 participants filled out an online questionnaire including the Italian version of the I-PVDQ (I-PVDQ) and several measures of psychological constructs. Reliability and factor analyses (single and multigroup) were conducted. Bayesian correlation tests and Bayesian independent sample t-tests were used to assess the validity of I-PVDQ.

RESULTS

Exploratory factor analysis supported the two-factor structure of the I-PVDQ, and factor loadings loaded appropriately onto perceived infectability (PI) and germ aversion (GA). In terms of invariance, the scale showed configural, metric, scalar, and strict invariance across genders. Decisive evidence in favor of correlation with the measure of COVID-19 related fears for both PI and GA was found. There was strong evidence for observed correlations with COVID-19 related constructs such as intolerance to uncertainty, psychological inflexibility, resilience, stress, and anxiety. Women showed higher GA than men, while there were no gender differences in PI.

CONCLUSIONS

Taken together, these results suggest that the I-PVDQ confirms the psychometric properties of the original version and that can be used to detect PVD when it is affected by environmental circumstances since its functioning is preserved during a pandemic.

The effect of the COVID-19 pandemic on disgust sensitivity in a sample of UK adults

The COVID-19 pandemic led to the introduction of a range of infection prevention and control (IPC) measures that resulted in dramatic changes in people's lives however these IPC measures are not practiced consistently across the population. One predictor of an individual's responses to the pandemic is disgust sensitivity. Understanding how disgust sensitivity varies within the population could help to inform design of public health messages to promote more uniform behavioral change during future pandemics. To understand the effect of the current COVID-19 pandemic on an individual's pathogen disgust sensitivity we have compared pathogen disgust sensitivity during the current COVID-19 pandemic to baseline pathogen disgust sensitivity, determined prior to the COVID-19 pandemic, in the same sample of UK adults. We find that the COVID-19 pandemic did not alter overall pathogen disgust sensitivity suggesting that disgust sensitivity is stable despite IPC measures, public health messaging, media coverage and other factors associated with the COVID-19 pandemic.

Behavioral avoidance of contagious and non-contagious adults

Evolutionary theories of disease avoidance propose that humans have a set of universal psychological processes to detect environmental cues indicative of infectious disease. These processes then initiate cognitive, emotional, and behavioral responses that function to limit contact with harmful pathogens. Here, we study the conditions under which people exhibit behavioral avoidance of others with a contagious illness or a physical injury (i.e., a broken leg), and the potential mechanisms that underlie this behavior. Across three studies, participants were given the option of sitting at one of two workstations previously occupied by two confederates, one of whom either showed visible symptoms of a cold (contagion condition), wore a lower-leg orthopedic boot and used crutches (broken leg condition), or showed no signs of illness or physical injury (control). We found strong evidence that adults explicitly avoid contact with individuals who show symptoms of a contagious illness. Further, we provide some evidence that adults also avoid individuals with a physical injury, but that this behavior might be driven by implicit, unconscious processes. The findings are discussed in terms of implications for the healthy avoidance of contagion, and the risk for potential stigmatization of non-contagious groups.

Women amid the COVID-19 pandemic: Self-protection through the behavioral immune system

Studies of the activation of the behavioral immune system triggered by the coronavirus disease-2019 pandemic have demonstrated that evolutionary explanations of individual differences in self-protection should not be based only on parental investment and sexual selection theory. An evolutionary model must also incorporate individual differences that arise within each sex as a result of life history strategies and attachment patterns.

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.

Health-Promoting Quality of Life at Work during the COVID-19 Pandemic: A 12-Month Longitudinal Study on the Work-Related Sense of Coherence in Acute Care Healthcare Professionals

(1) Background: During a pandemic, the wellbeing of healthcare professionals is crucial. We investigated the long-term association of the Work-related Sense of Coherence (Work-SoC) and the evolution of psychological health symptoms of acute care healthcare professionals during the first year of the COVID-19 pandemic. (2) Methods: This longitudinal observational study enrolled 520 multinational healthcare professionals, who completed an online survey every three months from April 2020 to April 2021. Mixed linear models examined the associations between Work-SOC and COVID-19-related anxiety, perceived vulnerability, depressiveness, and psychological trauma symptomatology. (3) Results: Healthcare professionals with a higher Work-SoC reported lower levels of COVID-19-related anxiety, perceived vulnerability, depressiveness, and psychological trauma symptomatology in April 2020 than healthcare professionals with an average or lower Work-SoC, but the levels increased to higher values in April 2021. Healthcare professionals with a lower Work-SoC reported higher levels of depressiveness and psychological trauma symptomatology in April 2020 but lower levels in April 2021. (4) Conclusions: Healthcare professionals with higher levels of Work-related Sense of Coherence might be protected against variations in psychological symptoms for about three months, but this protection seems to decrease as the pandemic continues, resulting in mental health deterioration. In contrast, healthcare professionals with a lower Work-SoC might be protected at later stages of the pandemic.

The behavioral immune system and vaccination intentions during the coronavirus pandemic

The behavioral immune system is considered to be a psychological adaptation that decreases the risk of infection. Research suggests that, in the current environment, this system can produce attitudes with negative health consequences, such as increased vaccine hesitancy. In three studies, we investigated whether two facets of the behavioral immune system-germ aversion (i.e., aversion to potential pathogen transmission) and perceived infectability (i.e., perceived susceptibility to disease)-predicted intentions to accept COVID-19 and influenza vaccination during the pandemic. The behavioral immune system mechanisms were measured before the COVID-19 pandemic in one study, and during the pandemic in two. In contrast to previous research, those with higher germ aversion during the pandemic perceived vaccines to be safer and had higher intentions to accept vaccination. Germ aversion before the pandemic was not associated with vaccination intentions. Individuals who perceived themselves as more susceptible to disease were slightly more willing to accept vaccination. We conjecture that high disease threat reverses the relationship between the behavioral immune system response and vaccination. As the associations were weak, individual differences in germ aversion and perceived infectability are of little practical relevance for vaccine uptake.

"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.

Deontological Guilt and Disgust Sensitivity Modulate Moral Behaviour

OBJECTIVE

Deontological Guilt (DG), and Altruistic Guilt (AG) emerge from the appraisal of violating an internalized rule or an altruistic principle, respectively. DG is strictly connected with Disgust Sensitivity and plays a key role in the development and maintenance of Obsessive-Compulsive Disorder (OCD). Previous studies investigated how DG affects responses to hypothetical moral dilemmas, however how DG and Disgust Sensitivity interact modulating moral behavior is still unknown.

METHODS

STUDY 1. 46 healthy participants performed an ecological paradigm in which people can spontaneously decide to lie to obtain a reward (egoistic lie) or give it away (altruistic lie) after three emotional inductions: DG, AG or neutral. Furthermore, OCD traits, Morality, Guilt Propensity and Disgust Sensitivity were assessed by means of questionnaires. STUDY 2. 27 participants from the original sample were retested during the COVID-19 lockdown in Italy to ascertain whether the pandemic modified traits related to morality, disgust, guilt or OCD symptoms and whether these changes modulated moral behavior (measured by a task in which cheating was associated to higher pay-offs).

RESULTS

STUDY 1. Compared to the neutral, after the DG induction participants produced less altruistic and more egoistic lies. This effect was stronger in participants with high Disgust Sensitivity. STUDY 2. During the COVID-19 lockdown participants became more sensitive to the Authority pillar of the Moral Foundations and more sensitive to Disgust: this increment in deontological morality affected (im) moral behavior depending on changes in Disgust Sensitivity.

CONCLUSIONS

Our data suggest that people with high Disgust Sensitivity are more affected by deontological inductions which translate to higher immorality, supposedly by lowering their moral self-image. These results might have important clinical implications as they suggest that addressing Disgust Sensitivity in therapy, might also decrease the effect of guilt on patients' behavior.

Food disgust sensitivity predicts disease-preventing behaviour beyond the food domain in the COVID-19 pandemic in Germany

In the fight against the COVID-19 pandemic, personal hygiene behaviours such as proper handwashing have gained significantly more attention and interpersonal contact is performed with great care. Disgust, as a disease-avoidance mechanism, can play an important role in the promotion of hygiene behaviour. We know from previous research that pathogen disgust can be a predictor of an individual's behaviour in the pandemic. Given that the pandemic greatly affects our food and eating behaviour, the current study aims to add to the existing evidence and to complement it by investigating the role of food-specific disgust in the pandemic. For that, we conducted an online survey in Germany in April 2020, while the pandemic was spreading in Europe. A total of 519 participants completed the survey and provided information about their COVID-19-related attitudes and behaviours and about their food disgust sensitivity. The results show that food disgust sensitivity is an important predictor for an individual's feelings, shopping behaviour, and disease-preventive behaviour related to the COVID-19 pandemic. Given that the success of political measures to fight the pandemic critically depends on the population to support and follow the proposed measures, a better understanding of the factors driving individual behaviour is key. Implications for pandemic management are discussed.

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.

Trust in Science, Perceived Vulnerability to Disease, and Adherence to Pharmacological and Non-pharmacological COVID-19 Recommendations

Protection motivation theory (PMT) is a theoretical framework informative for understanding behavioral intentions and choices during exceptional and uncommon circumstances, such as a pandemic of respiratory infectious disease. PMT postulates both the threat appraisal and the coping appraisal as predictors of health behaviors. Recent advances in the field of behavioral immune system (BIS) research suggest that humans are equipped with a set of psychological adaptations enabling them to detect the disease-threat and activate behavioral avoidance of pathogens. The present study, set within PMT framework and informed by the BIS research, aimed to explain and predict voluntary adherence to COVID-19 guidelines by perceived personal risk and vulnerability to disease as threat appraisal variables, and trust in science as the response efficacy element of coping appraisal. Gender, age, belief in the second wave, perceived personal risk, germ aversion, and trust in science were all found to be significant positive predictors of the intent to adhere to non-pharmacological COVID-19 recommendations, with the belief in the second wave, germ aversion, and trust in science being the most important ones. On the other hand, only the belief in the second wave and trust in science were significant positive predictors of the intent to adhere to pharmacological COVID-19 recommendations (i.e., to vaccinate). Interventions aimed at enhancing preventative measures adherence should take into account that the psychological mechanisms underlying adherence to these two types of recommendations are not identical.

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.

Contamination fear in the time of the COVID-19 pandemic: A moderated mediation quasi-experimental model of the effect of disgust on outgroup bias towards diaspora

Disgust sensitivity plays a key role in generating and maintaining outgroup biases. To test our hypotheses, we used a quasi-experimental between-subjects design, in which participants were randomly assigned to a disgust induction condition (N = 102) or a non-induction neutral group (N = 92). The induction scenario featured the return of the diaspora to their home country due to COVID-19 concerns. In one scenario, the diaspora lied about the country they arrived from, and in the other, there was no moral transgression. We hypothesized that the effect of disgust sensitivity on dehumanization and aggressive tendencies passed through contamination fear and the moderated mediation model indicated that this indirect effect was stronger for participants in the disgust-induction than in the non-induction group. This effect was found for biological dehumanization and passive aggression outcomes, both related to outgroup bias. Consistent with the role of disgust as a disease-avoidance mechanism, our results suggest that disgust could facilitate stronger outgroup bias in the context of a high health threat, such as the COVID-19 pandemic.

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.

Pandemic Leadership: Sex Differences and Their Evolutionary-Developmental Origins

The COVID-19 pandemic has caused a global societal, economic, and social upheaval unseen in living memory. There have been substantial cross-national differences in the kinds of policies implemented by political decision-makers to prevent the spread of the virus, to test the population, and to manage infected patients. Among other factors, these policies vary with politicians' sex: early findings indicate that, on average, female leaders seem more focused on minimizing direct human suffering caused by the SARS-CoV-2 virus, while male leaders implement riskier short-term decisions, possibly aiming to minimize economic disruptions. These sex differences are consistent with broader findings in psychology, reflecting women's stronger empathy, higher pathogen disgust, health concern, care-taking orientation, and dislike for the suffering of other people-as well as men's higher risk-taking, Machiavellianism, psychopathy, narcissism, and focus on financial indicators of success and status. This review article contextualizes sex differences in pandemic leadership in an evolutionary framework. Evolution by natural selection is the only known process in nature that organizes organisms into higher degrees of functional order, or counteracts the unavoidable disorder that would otherwise ensue, and is therefore essential for explaining the origins of human sex differences. Differential sexual selection and parental investment between males and females, together with the sexual differentiation of the mammalian brain, drive sex differences in cognition and behavioral dispositions, underlying men's and women's leadership styles and decision-making during a global pandemic. According to the sexually dimorphic leadership specialization hypothesis, general psychobehavioral sex differences have been exapted during human evolution to create sexually dimorphic leadership styles. They may be facultatively co-opted by societies and/or followers when facing different kinds of ecological and/or sociopolitical threats, such as disease outbreaks or intergroup aggression. Early evidence indicates that against the invisible viral foe that can bring nations to their knees, the strategic circumspection of empathic feminine health "worriers" may bring more effective and humanitarian outcomes than the devil-may-care incaution of masculine risk-taking "warriors".