Behavioral Immune System Research Articles

From pathogens to paintings: A preliminary investigation into the behavioral immune system’s influence on visual aesthetic appreciation and perception.

From pathogens to paintings: A preliminary investigation into the behavioral immune system’s influence on visual aesthetic appreciation and perception.

Tolerating injustice when feeling in control: Personal control enhances the link between collectivism and coercion in the face of disease threats

Amid the COVID-19 pandemic, authorities worldwide imposed coercive regulations aimed at curbing the virus’s spread, often at the expense of individuals who were considered potential threats to public health. We argue that individual differences in their support for such actions can be understood from the perspective of an evolved “behavioral immune system”. We conducted two studies within the context of the “zero-COVID” policy in Mainland China. Study 1 recruited 819 Shanghai residents during a strict citywide lockdown and found that individuals’ collectivistic orientation and personal control over their lives predicted their tolerance of injustices involved in disease-control measures. Moreover, the effect of psychological collectivism was enhanced by personal control. Study 2 (N = 403) partly replicated these findings using hypothetical scenarios related to various fictitious viruses. Notably, the effects found in Study 1 only manifested in scenarios involving ambivalent pathogens, which are seldom fatal but highly contagious. Building on the functional flexibility principle of the behavioral immune system theory, we discussed the unique role of ambivalent pathogen signals in generating within-society variability and fine-tuning behavioral immune responses.

Do individual differences in perceived vulnerability to disease shape employees' work engagement?

The COVID-19 pandemic posed a significant impact on employees' work outcomes worldwide. However, it remains unclear whether some employees fared worse than others when facing work-related health threats and what role individual differences in vulnerability to disease played in shaping their work experiences. Integrating the evolutionary psychology perspective of the behavioral immune system with Job Demands-Resources Theory, we argue that a fundamental factor in how employees dealt with these threats was the extent to which they perceived themselves as vulnerable to infectious diseases. Employees with higher susceptibility to infectious diseases were predicted to experience heightened workplace safety concerns and engage less with their work. In addition, a health-oriented leadership style was expected to decrease employees' safety concerns and increase their work engagement, especially for the more vulnerable employees. To test hypotheses, we conducted a three-wave field survey and two vignette-based experiments on working adults in the United Kingdom at different stages of the pandemic. Results largely supported our predictions, revealing that employees who felt more vulnerable to infectious diseases were more concerned about their workplace safety, inhibiting their work engagement. We discuss these findings' theoretical and practical implications for promoting a safe and healthy post-pandemic workplace, especially for vulnerable employees.

When pandemic threat does not stoke xenophobia: evidence from a panel survey around COVID-19

ABSTRACT Studies have found that pandemics can heighten xenophobia among host citizens, often explained by the behavioral immune system theory or elite-driven scapegoating. However, most research has overlooked the role of pandemic-related economic restrictions and job loss on sentiment toward immigrants. To isolate this economic mechanism, we examine the case of Venezuelan migrants in Colombia before and during COVID-19. Despite the Colombian government's severe economic lockdown, few politicians blamed Venezuelans for the pandemic. Thus, any economic impact on xenophobia should be evident. Using a panel experimental survey of 374 Colombians, supplemented with 550 new respondents at endline, we find no evidence that exposure to COVID-19 changed attitudes towards Venezuelans, even for those directly affected by the pandemic. Yet, those who did not lose their jobs viewed Venezuelan migration more positively at endline, providing support for the economic effects of pandemics.

Why do we love pandas and hate cockroaches?

This review explores the intricate interplay of human emotions towards different animal species. It delves into the contrasting feelings we harbor towards appealing animals like pandas and our aversion towards others like cockroaches. Drawing from the evolutionary ethnobiology perspective, it uncovers how biophilia and biophobia, deeply rooted in our evolutionary past, shape our reactions to various species. We also examine the role of the Behavioral Immune System (BIS) in our aversion to pathogen-carrying arthropods, the impact of educational interventions on changing attitudes toward wildlife, and the influence of animation on human memory and attention. We underscore the significance of understanding these psychological mechanisms in conservation strategies. We highlight how the evolutionary naturalist mind, influenced by ancestral threats and contemporary challenges, is pivotal in fostering a more harmonious coexistence with nature.

Greater Self-reported Health is Associated with Lower Disgust: Evidence for Individual Calibration of the Behavioral Immune System

Greater Self-reported Health is Associated with Lower Disgust: Evidence for Individual Calibration of the Behavioral Immune System

The ‘Coronavirus Crisis’ and xenophobia in South Africa: How did the pandemic affect anti‐immigrant sentiment?

AbstractThe impact of the COVID‐19 pandemic on xenophobia in South Africa is little understood. The Behavioural Immune System (BIS) theory would predict that hostility towards immigrants increases during periods of heightened pathogen stress. This BIS‐hypothesis is tested against the relative strength of three other possible drivers of anti‐immigrant sentiment. These included anger at the national lockdown system, intertemporal relative deprivation, and racial transformation ideology. For these tests nationally representative data (N = 2996), gathered during the height of the ‘Omicron’ wave, were used. Multivariate analysis showed that COVID‐19 exposure was not associated with more negative sentiments towards immigrants. Fear‐based reactions to the Coronavirus were, in fact, correlated with pro‐immigrant attitudes. Intertemporal relative deprivation and transformation orientations were much better predictors of anti‐immigrant sentiment than pathogen stress. These findings raised questions about the applicability of the BIS‐hypothesis in the context of the Coronavirus and suggest new avenues of academic inquiry.

Does Triggering the Behavioural Immune System Influence Spatial Proximity? [Conference Presentation Abstract

Does Triggering the Behavioural Immune System Influence Spatial Proximity? [Conference Presentation Abstract

Frontal alpha asymmetries and behavioral immune system: moderating role of behavioral inhibition system

Background and purpose: Behavioral immune system is a cluster of psychological mechanisms enabling detection and avoidance of pathogens in one’s immediate environment. Its presumed activation has been implicated in myriads of psychological phenomena, stemming from pathogen related disgust to more complex behaviors, such as mate choice and xenophobic cognitions. However, little is known about its biological underpinnings. The aim of this preliminary study was twofold: 1) to explore the role of another neuropsychological system governing avoidant motivations, the behavioral inhibition system, in pathogen-induced disgust and 2) to determine if frontal hemispheric asymmetries (a neural correlate of avoidant motivations) might serve as indicators of behavioral immune system activation. Materials and methods: 62 participants completed the Behavioral inhibition scale. Based on their z-scores, two extreme groups were formed: high (n=9) and low behavioral inhibition (n=9) group. After the baseline EEG recordings, participants were exposed to a set of neutral stimuli, followed by a set of pathogen disgust inducing stimuli. The frontal asymmetry (FAA) indexes (lnR-LnL) were calculated within both low (8-10 Hz) and high (11-13 Hz) alpha frequency bands on analogue pairs of frontal electrodes. Results: There were no baseline FAA differences between groups. However, compared to low behavioral inhibition group, high behavioral inhibition group showed larger shifts in FAA on frontopolar locations while watching the pathogen related disgust-inducing stimuli, as compared to neutral photographs. Conclusions: This pattern of FAA shifts suggests that high behavioral inhibition individuals attend to pathogen threat related cues more readily, i.e., have a more reactive behavioral immune system. With this preliminary study we are proposing a new line of research in order to determine if there is evidence of a calibrated response in terms of interplay between one’s immune status and pathogen treat related neural reactivity.

The association between consumers' chronic concerns about infectious disease and anthropomorphism

AbstractAssigning human characteristics to products and brands (i.e., anthropomorphism) is a tactic commonly adopted by marketers. However, researchers have recently highlighted the importance of better understanding which consumers will be more (or less) responsive to these cues. Drawing on the behavioral immune system and anthropomorphism literatures, we hypothesize that consumers who are chronically concerned about their susceptibility to infectious disease will have a greater tendency to anthropomorphize nonhuman entities (e.g., nature, technology, and consumer products) because doing so creates relatively pathogen‐free sources of social connection. Importantly, we also predict that this tendency will be muted when consumers are highly germ averse. To test these predictions, we examined the relationships between perceived infectability and germ aversion, the two subscales of the established Perceived Vulnerability to Disease scale, and three different measures of consumers' tendency to anthropomorphize nonhuman entities. The results of four studies, including a preregistered, high‐powered replication, support our hypotheses and offer the first evidence of a context wherein perceived infectability and germ aversion interact.

The psychological costs of behavioral immunity following COVID-19 diagnosis

Prior COVID-19 infection may elevate activity of the behavioral immune system—the psychological mechanisms that foster avoidance of infection cues—to protect the individual from contracting the infection in the future. Such “adaptive behavioral immunity” may come with psychological costs, such as exacerbating the global pandemic’s disruption of social and emotional processes (i.e., pandemic disruption). To investigate that idea, we tested a mediational pathway linking prior COVID infection and pandemic disruption through behavioral immunity markers, assessed with subjective emotional ratings. This was tested in a sample of 734 Mechanical Turk workers who completed study procedures online during the global pandemic (September 2021–January 2022). Behavioral immunity markers were estimated with an affective image rating paradigm. Here, participants reported experienced disgust/fear and appraisals of sickness/harm risk to images varying in emotional content. Participants self-reported on their previous COVID-19 diagnosis history and level of pandemic disruption. The findings support the proposed mediational pathway and suggest that a prior COVID-19 infection is associated with broadly elevated threat emotionality, even to neutral stimuli that do not typically elicit threat emotions. This elevated threat emotionality was in turn related to disrupted socioemotional functioning within the pandemic context. These findings inform the psychological mechanisms that might predispose COVID survivors to mental health difficulties.

Conservatism Negatively Predicts Creativity: A Study Across 28 Countries

Previous studies have found a negative relationship between creativity and conservatism. However, as these studies were mostly conducted on samples of homogeneous nationality, the generalizability of the effect across different cultures is unknown. We addressed this gap by conducting a study in 28 countries. Based on the notion that attitudes can be shaped by both environmental and ecological factors, we hypothesized that parasite stress can also affect creativity and thus, its potential effects should be controlled for. The results of multilevel analyses showed that, as expected, conservatism was a significant predictor of lower creativity, adjusting for economic status, age, sex, education level, subjective susceptibility to disease, and country-level parasite stress. In addition, most of the variability in creativity was due to individual rather than country-level variance. Our study provides evidence for a weak but significant negative link between conservatism and creativity at the individual level (β = −0.08, p < .001) and no such effect when country-level conservatism was considered. We present our hypotheses considering previous findings on the behavioral immune system in humans.

Immune gene expression and epigenetic potential affect the consumption of risky food by female house sparrows

When organisms move into new areas, they are likely to encounter novel food resources. Even if they are nutritious, these foods can also be risky, as they might be contaminated by parasites. The behavioural immune system of animals could help them avoid the negative effects of contaminated resources, but our understanding of behavioural immunity is limited, particularly whether and how behavioural immunity interacts with physiological immunity. Here, we asked about the potential for interplay between these two traits, specifically how the propensity of an individual house sparrow (Passer domesticus) to take foraging risks was related to its ability to regulate a key facet of its immune response to bacterial pathogens. Previously, we found that sparrows at expanding geographic range edges were more exploratory and less risk-averse to novel foods; in those same populations, birds tended to over-express Toll-like receptor 4 (TLR4), a pattern-recognition receptor that distinguishes cell-wall components of Gram-negative bacteria, making it the major sensor of potentially lethal gut microbial infections including salmonellosis. When we investigated how birds would respond to a typical diet (i.e., mixed seeds) spiked with domesticated chicken faeces, birds that expressed more TLR4 or had higher epigenetic potential for TLR4 (more CpG dinucleotides in the putative gene promoter) ate more food, spiked or not. Females expressing abundant TLR4 were also willing to take more foraging risks and ate more spiked food. In males, TLR4 expression was not associated with risk-taking. Altogether, our results indicate that behaviour and immunity covary among individual house sparrows, particularly in females where those birds that maintain more immune surveillance also are more disposed to take foraging risks.

Evidence from 43 countries that disease leaves cultures unchanged in the short-term

Did cultures change shortly after, and in response to, the COVID-19 outbreak? If so, then in what way? We study these questions for a set of macro-cultural dimensions: collectivism/individualism, duty/joy, traditionalism/autonomy, and pro-fertility/individual-choice norms. We also study specific perceptions and norms like perceived threats to society (e.g. immigration) and hygiene norms. We draw on Evolutionary Modernization Theory, Parasite Stress Theory, and the Behavioural Immune System, and existing evidence, to make an overarching prediction: the COVID-19 pandemic should increase collectivism, duty, traditionalism, conformity (i.e. pro-fertility), and outgroup prejudice. We derive specific hypotheses from this prediction and use survey data from 29,761 respondents, in 55 cities and 43 countries, collected before (April–December 2019) and recently after the emergence of COVID-19 (March–July 2020) to test them. We exploit variation in disease intensity across regions to test potential mechanisms behind any changes. The macro-cultural dimensions remained stable. In contrast, specific perceptions and norms related to the pandemic changed: norms of hygiene substantially increased as did perceived threats related to disease. Taken together, our findings imply that macro-cultural dimensions are primarily stable while specific perceptions and norms, particularly those related to the pandemic, can change rapidly. Our findings provide new evidence for theories of cultural change and have implications for policy, public health, daily life, and future trajectories of our societies.

Money or health? The effect of pathogen avoidance motives and life history strategies on health‐economic trade‐offs during the COVID‐19 pandemic

AbstractThe COVID‐19 pandemic has caused governments and individuals to face important but difficult trade‐offs between health and the economy. How do individuals choose between health and economic outcomes during the pandemic? Based on the behavioural immune system (BIS) theory and the life history (LH) theory, the present study examined the effects of individual differences in pathogen disgust sensitivity and life history strategy on people's health‐economic trade‐offs during the COVID‐19 pandemic. Results of an online study (N = 300) showed that people with higher pathogen disgust sensitivity felt less sense of control during the pandemic, and therefore chose health‐related options over economic‐related options. In addition, the association between pathogen disgust sensitivity and health outcome preference only existed in people with relatively faster life history strategies. Further, people's health‐economic trade‐offs were not influenced by their current economic status. Findings have important implications for policymakers and the public to understand people's health‐economic choices during the pandemic.

Human emotional evaluation of ancestral and modern threats: fear, disgust, and anger.

Animal and human ancestors developed complex physiological and behavioral response systems to cope with two types of threats: immediate physical harm from predators or conspecifics, triggering fear, and the risk of infections from parasites and pathogens leading to the evolution of the behavioral immune system with disgust as the key emotion. Integration of the evolutionary concepts of the fear module and behavioral immune systems has been infrequent, despite the significant survival advantages of disgust in various contexts. Studies comparing attention to ancestral and modern threats accompanied by fear have yielded ambiguous results and what qualifies as salient modern disgusting stimuli remains unclear. We do not know whether disgust or the behavioral immune system, as inherent aspects of human psychology, have adapted to safeguard us from pandemic risks or poisoning by modern toxic substances. To test these effects, we have developed a survey comprised of 60 short vignettes describing threats evoking fear and disgust belonging to one of the three main categories of threats: (1) ancestral (phylogenetic), (2) modern (ontogenetic), and (3) pandemics of airborne disease. Each vignette was evaluated on a 7-point Likert scale based on fear, disgust, and anger. In total, 660 respondents completed the survey. The data were analysed using a factor analysis and general linear model with the respondent as a random factor. The results show that the strongest fear is triggered by modern threats (electricity, car accidents), while the highest disgust is evoked by ancient threats (body waste products, worms, etc.). Interestingly, disgust does not respond to modern threat stimuli such as toxic substances or radioactivity as these evoke mainly fear and anger. Finally, a distinct response pattern was found for pandemic threats, in which both fear (e.g., of disease and death) and disgust (e.g., of used face masks) are employed. Our study offers valuable insights into the emotional responses to ancestral and modern threats and their adaptation to pandemic challenges. Ancestral threats are not always more powerful stimuli than adequate threats of the modern type, but they function specifically. Thus, snakes and heights as fear-inducing ancestral threats form separate factors in a multivariate analysis, whereas all ancestral disgust stimuli group together. The threat of a pandemic forms a specific category and people process it emotionally and cognitively. These insights contribute to our understanding of human psychology and behavior in an ever-changing world.

Looking beyond vaccines: Cultural tightness-looseness moderates the relationship between immunization coverage and disease prevention vigilance.

Advancements in vaccination technologies mitigate disease transmission risks but may inadvertently suppress the behavioral immune system, an evolved disease avoidance mechanism. Applying behavioral immune system theory and utilizing robust big data analytics, we examined associations between rising vaccination coverage and government policies, public mobility, and online information seeking regarding disease precautions. We tested whether cultural tightness-looseness moderates the relationship between mass immunization and disease prevention vigilance. Comprehensive time series analyses were conducted using American data (Study 1) and international data (Study 2), employing transfer function modeling, cross-correlation function analysis, and meta-regression analysis. Across both the US and global analyses, as vaccination rates rose over time, government COVID-19 restrictions significantly relaxed, community mobility increased, and online searches for prevention information declined. The relationship between higher vaccination rates and lower disease prevention vigilance was stronger in culturally looser contexts. Results provide initial evidence that mass immunization may be associated with attenuated sensitivity and enhanced flexibility of disease avoidance psychology and actions. However, cultural tightness-looseness significantly moderates this relationship, with tighter cultures displaying sustained vigilance amidst immunization upticks. These findings offer valuable perspectives to inform nuanced policymaking and public health strategies that balance prudent precautions against undue alarm when expanding vaccine coverage worldwide.

The impact of COVID-19 concerns on perceiving others' faces.

Unlike most infectious diseases, COVID-19 is characterised by an absence of facial disease-signalling cues. Yet, it is still unclear whether it has influenced face perception. Understanding this may help clarify if and how our motivation toward social interactions is conditional on situational pathogen threats. The present study investigated if priming disease concerns about COVID-19 would change people's perception of neutral faces on perceived disease, social discomfort and arousal elicited by such faces; this condition was compared with other infectious/non-infectious diseases and a non-disease priming condition. One-hundred sixty-six participants recruited nationally performed the online task. When compared with the non-disease condition, participants primed for COVID-19 perceived faces as sicker and tended to view them as eliciting more social discomfort; no difference occurred in arousal. No other difference was found between conditions. These findings suggest that the pandemic context can shape how we perceive others' apparent sickness. Overall, these might reflect adaptations intertwined with the behavioural immune system's defence mechanisms.

Think positive! Resolving human motion ambiguity in the presence of disease threat

ABSTRACT Recently, approach-avoidance tendencies and visual perception biases have been increasingly studied using bistable point-light walkers (PLWs). Prior studies have found a facing-the-viewer bias when one is primed with general threat stimuli (e.g. angry faces), explained by the “error management theory”, as failing to detect a threat as approaching is riskier than the opposite. Importantly, no study has explored how disease threat – linked to the behavioural immune system – might affect this bias. This study aimed to explore whether disease-signalling cues can alter how we perceive the motion direction of ambiguous PLWs. Throughout 3 experiments, participants indicated the motion direction of a bistable PLW previously primed with a control or disease-signalling stimuli – that is, face with a surgical mask (Experiment 1), sickness sound (Experiment 2), or face with a disease cue (Experiment 3). Results showed that sickness cues do not significantly modulate the perception of approach-avoidance behaviours. However, a pattern emerged in Experiments 2 and 3, suggesting that sickness stimuli led to more facing away percepts. Unlike other types of threat, this implies that disease-related threat stimuli might trigger a distinct perceptual bias, indicating a preference to avoid a possible infection source. Nonetheless, this finding warrants future investigations.

Resting parasympathetic activity is associated with malodor-induced change in perceived foreignness of speakers.

To protect against infection, individuals have evolved context-dependent pathogen-avoidant strategies, including selective social behaviors aimed at avoiding foreign individuals who may possess greater risk of infection. Parasympathetic nervous system (PNS) activity is associated with social engagement and regulation of the classical immune system but has not been widely investigated in relation to changes in intergroup perception and the behavioral immune system. The current research investigated the relationship between parasympathetic activity and perceived foreignness of in and outgroup speakers during exposure to a pathogen-relevant odor (butyric acid). High-frequency heart rate variability was measured at rest and while participants rated foreignness of speakers with and without the odor present. Findings show that exposure to the odor was associated with higher foreignness perceptions of outgroup speakers and lower foreignness perceptions of ingroup speakers. This effect was especially evident among individuals with higher resting parasympathetic activity. These results suggest that the PNS may play a role in changes in social perceptions during a behavioral immune response.