Behavioral Immune System Research Articles

The behavioural immune system and pandemic psychology: the evolved psychology of disease-avoidance and its implications for attitudes, behaviour, and public health during epidemic outbreaks

ABSTRACT This article provides an overview of the “behavioural immune system” – a suite of psychological mechanisms that complements immunological defences by motivating pre-emptive behavioural responses to infection threats – and summarises research documenting its implications for social attitudes and social behaviour. This summary focuses on four domains of phenomena: interpersonal interactions, stigma and prejudice, conformity, and political attitudes. Then, drawing on this conceptual and empirical background, the article discusses consequences that disease outbreaks (such as the COVID-19 pandemic) may have for individuals’ attitudes and actions, and the further consequences that these attitudes and actions might plausibly have for population-level epidemiological and public health outcomes.

Customers’ Behavioural Immune System Responses to the COVID-19 Pandemic: A conceptual framework

The COVID-19 pandemic has imposed various obstacles and restrictions for the tourism and hospitality industry. This paper adopts the concept of the behavioural immune system to discuss tourism and hospitality customers’ potential behaviours during the pandemic and provide business strategies that can address these behaviours. The behavioural immune system is a motivational system that determines individuals’ behaviours to pathogen infection. First, this study introduces the mechanism of the behavioural immune system including environmental evaluation and aversive perception, aversive emotional and cognitive responses, and avoidance behaviours. It also provides examples in the guest service context to better portray the mechanism. Second, the study suggests specific measures for tourism and hospitality businesses that may help them to prevent the aversive and avoidance responses of customers triggered by their behavioural immune system during the pandemic. Then, the study integrates customers’ responses and businesses’ measures in a framework, which extends the literature on customers’ behaviour in the hospitality and tourism context. To the authors’ knowledge, this is the first time the concept of behavioural immune system is adopted to discuss customers’ behaviours towards tourism and hospitality services during a pandemic.

COVID-19 concerns in cyberspace predict human reduced dispersal in the real world: Meta-regression analysis of time series relationships across American states and 115 countries/territories

On the basis of parasite-stress theory of sociality and behavioral immune system theory, this research examined how concerns regarding the Coronavirus disease 2019 (COVID-19) in cyberspace (i.e., online search volume for coronavirus-related keywords) would predict human reduced dispersal in the real world (i.e., human mobility trends throughout the pandemic) between January 05, 2020 and May 22, 2021. Multiple regression analyses controlling for COVID-19 cases per million, case fatality rate, death-thought accessibility, government stringency index, yearly trends, season, religious holidays, and reduced dispersal in the preceding week were conducted. Meta-regression analysis of the multiple regression results showed that when there were high levels of COVID-19 concerns in cyberspace in a given week, the amount of time people spent at home increased from the previous week across American states (Study 1) and 115 countries/territories (Study 2). Across studies, the associations between COVID-19 concerns and reduced dispersal were stronger in areas of higher historical risks of infectious-disease contagion. Compared with actual coronavirus threat, COVID-19 concerns in cyberspace had significantly larger effects on predicting human reduced dispersal in the real world. Thus, online query data have invaluable implications for predicting large-scale behavioral changes in response to life-threatening events in the real world and are indispensable for COVID-19 surveillance.

Individual Differences in Political Ideology and Disgust Sensitivity Affect Real-Time Spoken Language Comprehension.

Individuals' moral views have been shown to affect their event-related potentials (ERP) response to spoken statements, and people's political ideology has been shown to guide their sentence completion behavior. Using pupillometry, we asked whether political ideology and disgust sensitivity affect online spoken language comprehension. 60 native speakers of English listened to spoken utterances while their pupil size was tracked. Some of those utterances contained grammatical errors, semantic anomalies, or socio-cultural violations, statements incongruent with existing gender stereotypes and perceived speaker identity, such as “I sometimes buy my bras at Hudson's Bay,” spoken by a male speaker. An individual's disgust sensitivity is associated with the Behavioral Immune System, and may be correlated with socio-political attitudes, for example regarding out-group stigmatization. We found that more disgust-sensitive individuals showed greater pupil dilation with semantic anomalies and socio-cultural violations. However, political views differently affected the processing of the two types of violations: whereas more conservative listeners showed a greater pupil response to socio-cultural violations, more progressive listeners engaged more with semantic anomalies, but this effect appeared much later in the pupil record.

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.

Are we behaviorally immune to COVID-19 through robots?

In the context of the health risks of the COVID-19 pandemic, tourists' choices have shifted to reflect a subconscious psychological mechanism – the behavioral immune system – that facilitates human organisms to better identify plausible threats to ones' health through environment cues. This research draws upon this theoretical lens to assess tourists' pre-trip hotel evaluation in two 2 × 2 between-subject experiments. Experiment 1 (robot vs. human) tested the service provider's effect on hotel selection evaluation through the mediation of sense of control and the moderation of pandemic risk. Experiment 2 examined this chain of relationship through the moderation of hotel type. This research contributes to the literature by underscoring the pathogen-avoidance mechanism in tourist evaluation and the peril of robotization.

"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.

Taking a social perspective on moral disgust

AbstractResearch on moral disgust suffers from a methodological bias. The bulk of such investigation focuses almost exclusively on the operation of moral disgust within the psychology of a single individual, or as involving an interaction between two people. This leads to certain questions being salient, while other phenomena, which emerge only at the level of an entire community or society, are largely hidden from view. The present paper explains and defends a perspective that emphasizes the role of moral disgust within a community. It also illustrates the usefulness of this perspective by applying it to three quite distinct accounts of moral disgust: Alexandra Plakias’s response model of moral disgust, David Pizarro’s idea that moral disgust is part of a behavioral immune system, and Jesse Prinz’s self‐consciously simple form of moral sentimentalism.

The psychological and socio-political consequences of infectious diseases: Authoritarianism, governance, and nonzoonotic (human-to-human) infection transmission

What are the socio-political consequences of infectious diseases? Humans have evolved to avoid disease and infection, resulting in a set of psychological mechanisms that promote disease-avoidance, referred to as the behavioral immune system (BIS). One manifestation of the BIS is the cautious avoidance of unfamiliar, foreign, or potentially contaminating stimuli. Specifically, when disease infection risk is salient or prevalent, authoritarian attitudes can emerge that seek to avoid and reject foreign outgroups while favoring homogenous, familiar ingroups. In the largest study conducted on the topic to date (N > 240,000), elevated regional levels of infectious pathogens were related to more authoritarian attitudes on three geographical levels: across U.S. metropolitan regions, U.S. states, and cross-culturally across 47 countries. The link between pathogen prevalence and authoritarian psychological dispositions predicted conservative voting behavior in the 2016 U.S. Presidential Election and more authoritarian governance and state laws, in which one group of people imposes asymmetrical laws on others in a hierarchical structure. Furthermore, cross-cultural analysis illustrated that the relationship between infectious diseases and authoritarianism was pronounced for infectious diseases that can be acquired from other humans (nonzoonotic), and does not generalize to other infectious diseases that can only be acquired from non-human species (zoonotic diseases). At a time of heightened awareness of infectious diseases, the current findings are important reminders that public health and ecology can have ramifications for socio-political attitudes by shaping how citizens vote and are governed.

Filthy Animals: Integrating the Behavioral Immune System and Disgust into a Model of Prophylactic Dehumanization

The behavioral immune system (BIS) is an evolved psychological mechanism that motivates prophylactic avoidance of disease vectors by eliciting disgust. When felt toward social groups, disgust can dampen empathy and promote dehumanization. Therefore, we investigated whether the BIS facilitates the dehumanization of groups associated with disease by inspiring disgust toward them. An initial content analysis found that Nazi propaganda predominantly dehumanized Jews by portraying them as disease vectors or contaminants. This inspired three correlational studies supporting a Prophylactic Dehumanization Model in which the BIS predicted disgust toward disease-relevant outgroups, and this disgust in turn accounted for the dehumanization of these groups. In a final study, we found this process of prophylactic dehumanization had a downstream effect on increasing anti-immigrant attitudes during the COVID-19 pandemic. However, consistent with the evolutionary logic of a functionally flexible BIS, this effect only occurred when the threat of COVID-19 was salient. The implications of these results for the study of dehumanization and evolutionary theories of xenophobia are discussed.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40806-021-00296-8.

Linking the behavioral immune system to COVID-19 vaccination intention: The mediating role of the need for cognitive closure and vaccine hesitancy

Vaccination has become one of the most effective ways of controlling the spread of COVID-19. Consequently, revealing the evolutionary and cognitive antecedents of COVID-19 vaccine hesitancy and vaccination intention has become crucial. Drawing on the theory of behavioral immune system (BIS), we investigate whether perceived vulnerability to disease (PVD) is associated with vaccination intentions through the need for cognitive closure (NCC) and vaccine hesitancy. The data was collected from 525 adults from Turkey. The structural equation modeling results indicate that of the two dimensions of PVD, germ aversion predicts COVID-19 vaccination intention through sequential mediation of NCC and vaccine hesitancy. Perceived infectability, on the other hand, is directly and positively related to vaccination intention. By showing the mediating role of NCC, our results offer an insight as to why germ aversion translates into vaccine hesitancy, and low vaccination intention. We discuss the potential benefits of considering the roles of BIS and NCC in campaigns and policies targeted at increasing COVID-19 vaccine uptake and suggest implications for such practices.

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.

Stigmatization of Chinese and Asian-looking people during the COVID-19 pandemic in Germany

BackgroundThe outbreak and global spread of COVID-19 was accompanied by an increase in reports of stigmatization of Chinese and Asian-looking people. The behavioral immune system provides a framework for stigmatization in response to infectious disease threats. Specifically, stigmatization might increase with rising levels of infectious disease threat. The present study aimed to examine this hypothesis during the early phase of the COVID-19 pandemic.MethodsAs part of the “EUCLID” project (https://euclid.dbvis.de), a total of 5011 persons from Germany were surveyed via an online-questionnaire between February 2nd and April 3rd, 2020, covering the progression of the COVID-19 pandemic over three time periods which were defined by critical events.ResultsThere was no evidence for an increase in the stigmatization of Chinese and Asian-looking people across three topics, that is personal proximity, air travel, and medical measures upon arrival from China.ConclusionsThe present findings provide good news in that participants showed an adaptive response to the infectious disease threat rather than displaying increased stigmatization. Further research is necessary to specify the conditions that increase the risk of stigmatization in response to infectious disease threats.

Pathogen Threat and In-group Cooperation.

Disease-causing parasites and pathogens play a pivotal role in intergroup behavior. Previous studies have suggested that the selection pressure posed by pathogen threat has resulted in in-group assortative sociality, including xenophobia and in-group favoritism. While the current literature has collated numerous studies on the former, strikingly, there has not been much research on the relationship between pathogen threat and in-group cooperation. Drawing upon prior studies on the function of the behavioral immune system (BIS), we argued that the BIS might facilitate cooperation with in-group members as a reactive behavioral immune response to pathogen threat. More specifically, we held that individuals might utilize cooperative behavior to ensure that they can receive social support when they have contracted an infectious disease. We reviewed existing findings pertaining to the potential role of the BIS in in-group cooperation and discussed directions for future studies.

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.

The role of the behavioural immune system in stigma related to skin diseases needs to be explored.

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Evaluation of Behavioral Immune System and its Unique Effect on Prejudice and Stigmatization in Patients with Infectious Diseases

Introduction: Behavioral immune systems allow organisms to detect the presence of disease-causing pathogens in their environment more immediately and engage in behaviors that prevent them from coming into contact with objects and individuals. There is extensive research linking behavioral immune systems to a variety of prejudices. These prejudices cause labeling and ultimately social stigma on these people. Therefore, the present study investigated the behavioral safety system and its unique effect on prejudice and stigmatization in people with infectious diseases. In this review study, the research literature was searched through Google Scholar and PubMed with the words "Behavioral Immune System, Prejudice, Stigmatization", and the relevant authorities were included in this study. Research has shown that people tend to associate illness with obesity, the manifestation of facial symptoms, physical disability, and foreign nationality in order to avoid becoming ill by predicting illness and thus overreacting to them. These reactions occur in many groups of people who do not actually have the contagious disease and are called a type of psychological allergy. These prejudicial reactions and labeling can cause social distress for these people and their long-term social isolation. Conclusion: Disgust is triggered in response to pathogen-related stimuli and is associated with unique patterns of autonomic nervous system activity and neural activity, but in functional connections between anatomical structures, chemical neurological processes, and various cognitive and behavioral phenomena, the genetic structure is involved. Demonstrating behavioral immunity, there is not much information and more study is needed.

Perceptions of Infectability to Disease Moderate the Association between Daily Concerns about Contracting COVID-19 and Satisfaction with Sex.

The behavioral immune system is an evolved adaptation comprised of automatic behavioral, cognitive, and affective reactions that has allowed humans throughout evolutionary history to avoid situations that risk infection by pathogens (e.g., physical proximity to sick people). Although behavioral immune system activation may be functional by helping people avoid such situations, experiencing these automatic reactions during sexual interactions may undermine people’s evaluations of those interactions because sex requires close physical contact. We examined whether two sources of behavioral immune system activation (daily concern over contracting COVID-19 and individual differences in infection concern) undermined satisfaction with sex among 318 partnered adults in the U.S. during the COVID-19 pandemic. Participants reported individual differences in perceived infectability and then, every night for two weeks, reported their (a) daily concern about contracting COVID-19, (b) daily stress, (c) whether they had sex with their partner, and (d) their satisfaction with sex when it occurred. People’s perceived infectability moderated the association between their daily concern about contracting COVID-19 and the extent to which they enjoyed sex when it occurred, such that people higher, but not lower, in perceived infectability enjoyed sex less on days that they were more worried about contracting COVID-19 than usual. This effect was not moderated by biological sex and remained significant when controlling for biological sex, age, relationship length, and frequency of sex. Results highlight the importance of the behavioral immune system to sexual functioning and suggest a novel avenue through which the COVID-19 pandemic has disrupted relationships.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10508-021-02076-8.

Contagious Health Risk and Precautionary Social Distancing.

BackgroundSince humans are social animals, social relations are incredibly important. However, in cases of contagious diseases such as the flu, social contacts also pose a health risk. According to prominent health behavior change theories, perceiving a risk for one’s health motivates precautionary behaviors. The “behavioral immune system” approach suggests that social distancing might be triggered as a precautionary, evolutionarily learned behavior to prevent transmitting contagious diseases through social contact. This study examines the link between personal risk perception for an infectious disease and precautionary behavior for disease-prevention in the context of social relationships.MethodsAt 2-week intervals during the first semester, 100 Psychology freshmen indicated their flu risk perception, whether they had been ill during the previous week, and their friendships within their freshmen network for eight time points.ResultsSocial network analysis revealed that participants who reported a high flu risk perception listed fewer friends (B = −0.10, OR = 0.91, p = 0.026), and were more likely to be ill at the next measuring point (B = 0.26, OR = 1.30, p = 0.005). Incoming friendship nominations increased the likelihood of illness (B = 0.14, OR = 1.15, p = 0.008), while the reduced number of friendship nominations only marginally decreased this likelihood (B = −0.07, OR = 0.93, p = 0.052).ConclusionIn accordance with the concept of a “behavioral immune system,” participants with high flu risk perception displayed a social precautionary distancing even when in an environment, in which the behavior was ineffective to prevent an illness.