Disgust as a mechanism for decision making under risk: Illuminating sex differences and individual risk-taking correlates of disgust propensity

Four studies yield limited evidence for prepared (disgust) learning via evaluative conditioning

Prepared learning accounts suggest that specialized learning mechanisms increase the retention of associations linked to ancestrally-prevalent threats. Few studies have investigated specialized aversion learning for pathogen threats. In four pre-registered studies (N's = 515, 495, 164, 175), we employed an evaluative conditioning procedure to test whether foods (versus non-foods) are more readily associated with negative content associated with pathogens than negative content not associated with pathogens. Participants saw negatively valenced (either pathogen-relevant or -irrelevant), neutral or positively-valenced stimuli paired with meats and plants (in Studies 1 and 2) and with meats and abstract shapes (in Studies 3 and 4). They then evaluated each stimulus explicitly via self-reports (Studies 1-4) and implicitly via an Affect Misattribution Procedure (Studies 3 and 4). Linear mixed models revealed general evaluative conditioning effects, but inconsistent evidence for specialized (implicit or explicit) learning for a food-pathogen association. However, results from a mega-analysis across studies revealed stronger conditioning effects for meats paired with pathogen-relevant negative stimuli than pathogen-irrelevant negative stimuli.

WITHDRAWN: Four studies Yield limited evidence for prepared (disgust) learning via evaluative conditioning

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Evaluating the Presence of Disgust in Animals

The emotion of disgust in humans is widely considered to represent a continuation of the disease-avoidance behavior ubiquitous in animals. The extent to which analogs of human disgust are evident in nonhuman animals, however, remains unclear. The scant research explicitly investigating disgust in animals has predominantly focused on great apes and suggests that disgust might be present in a highly muted form. In this review, we outline the main approaches to disgust. We then briefly discuss disease-avoidance behavior in nonhuman animals, proposing a set of criteria against which evidence for the presence or absence of disgust in animals can be evaluated. The resultant decision tree takes into account other plausible causes of avoidance and aversion when evaluating whether it is likely that the behavior represents disgust. We apply this decision tree to evaluate evidence of disgust-like behavior (e.g., avoidance of carrion and avoidance of feces-contaminated food) in several examples, including nonhuman great apes. Finally, we consider the large disparity between disgust in humans compared to muted disgust in other great apes, examining the possibility that heightened disgust in humans is a relatively recent cultural acquisition.

Are cooks more disgust sensitive? Preliminary examination of the food preparation hypothesis

According to the food preparation hypothesis, sex differences in disgust sensitivity may stem from different sex roles that males and females played in our ancestral times. In current times, these differences may be reflected in varying levels of disgust sensitivity between people who frequently versus rarely engage in meal preparation, or who are versus are not professionally responsible for providing meals for others. To test this reasoning, we conducted a preregistered study with 493 individuals (55% female), with 280 of them working in the restaurant industry. Participants reported their weekly time spent on cooking-related activities and completed the Food Disgust Scale and pathogen subscale of Three Domain Disgust Scale. These measures capture specific, food-related disgust sensitivity, and generalised pathogen disgust sensitivity, respectively. We found that while time spent on cooking was not associated with disgust sensitivity, people professionally engaged in food preparation displayed higher levels of food-related disgust sensitivity. There was no effect of cooking on the generalised pathogen disgust sensitivity. Additionally, we observed sex differences in both types of disgust sensitivity and found that vegetarians exhibited lower disgust sensitivity than meat-eaters. Overall, our findings offer preliminary support for the food preparation hypothesis, and point out that the mechanisms adjusting our disgust sensitivity levels are category-specific, even within the broader pathogen disgust domain.

Do Experimental Manipulations of Pathogen Avoidance Motivations Influence Conformity?

By conforming to ingroup norms, individuals coordinate with other group members, preserve cohesion, and avoid costs of exclusion. Previous experiments have shown that increased concerns about infectious disease increase conformity. However, coordination with other group members has multiple benefits, most of which exist independent of pathogenic infection. Hence, a strong causal effect of pathogen avoidance motivations on conformity seems unlikely. Results from five experiments (N = 1,931) showed only limited support for the hypothesis that experimentally increasing pathogen avoidance motivations influences conformity. Overall, our findings are not consistent with the notion that the human mind contains a fast-acting psychological mechanism that regulates conformity as a function of short-term pathogen avoidance motivations.

Females undergo selection too

Extending Campbell's (1999) staying alive theory (SAT) beyond aggression, we reviewed evidence that females are more self-protective than males. Many commentators provided additional supporting data. Sex differences in life-history adaptations, in the optimal relation between survival and reproduction, and in the mechanisms underlying trade-offs involved with self-protection remain important topics with numerous opportunities for improved understanding.

Early adversity, adult lifestyle, and posttraumatic stress disorder in a military sample

Early adversity is considered a major risk factor for adult posttraumatic stress disorder (PTSD). Simultaneously, however, early adversity is also known to contribute to psychological resilience, and, indeed, some high-adversity groups do not display elevated PTSD risk. We explored correlates of PTSD in the Study to Assess Risk and Resilience in Servicemembers military dataset to evaluate contrasting accounts of the relationship between early adversity and PTSD. The standard deficit model depicts ontogeny as inherently vulnerable to insult, such that early adversity yields a less robust adult phenotype. A complementary life history theory account holds that adverse early experiences cue a fast life history orientation that reduces investment in maintenance, yielding an adult phenotype less able to recover from trauma. An opposing life history theory account holds that early adversity cues expectations of an adverse adult environment, adaptively reducing reactivity to adverse events. We use principal component analysis to extract a latent variable representing several childhood experiences and multiple lifestyle factors that plausibly proxy life history orientation. After correcting for covariates, we find a strong positive influence of such proxies on PTSD risk, suggesting that early adversity may indeed increase risk for PTSD, and thus that either the standard deficit model, the reduced maintenance account or a combination are correct.

Pathogen disgust sensitivity: Individual differences in pathogen perception or pathogen avoidance?

The emotion disgust motivates the avoidance of pathogens and contaminants. Individuals differ in their tendency to experience disgust and this is referred to as pathogen disgust sensitivity. Yet, it remains unclear which differences in psychological processes are captured by pathogen disgust sensitivity. We tested two hypotheses about how the information processing structure underlying pathogen avoidance might give rise to individual differences in pathogen disgust sensitivity. Participants (n = 998) rated the perceived health of individuals with or without facial blemishes and indicated how comfortable they would feel about having physical contact with them. For participants with high disgust sensitivity, facial blemishes were more indicative of poor health and perceived health was more strongly related to comfort with physical contact. These findings suggest that pathogen disgust sensitivity reflects individual differences in the tendency to interpret stimuli as an infection risk and the weight given to estimated infection risk when deciding who should be approached or avoided.

Episodic future thinking and anticipatory emotions: Effects on delay discounting and preventive behaviors during COVID-19

We examined the effects of anticipatory emotions induced by episodic future thinking on the basic decision‐process of delay discounting and preventive behaviors during the most stringent COVID‐19 “lockdown” period in China. We define anticipatory emotions as any discrete emotions induced from anticipating decision outcomes and felt during decision‐making. In an online study conducted with healthy volunteers, anticipatory emotions were induced and appraised by asking participants to rate various emotions they feel when thinking they may be infected by COVID‐19 (N = 246). The participants in the control group reported their present emotions during the COVID‐19 pandemic (N = 245). Compared with the control group, the participants in the anticipatory emotion group had a higher future‐oriented preference for monetary rewards, with a significantly lower delay discounting rate. These participants also had a higher intention to engage in proactive, preventive behaviors. The likelihood estimate of being infected by COVID‐19 mediated these effects. Moreover, anticipatory disgust increased the preference for larger‐and‐later rewards. Anticipatory emotions induced by future thinking guide fast and rational decision‐making in a health crisis.

"I Feel Therefore I Decide": Effect of Negative Emotions on Temporal Discounting and Probability Discounting

Temporal and probability discounting are considered two fundamental constructs in economic science, as they are associated with phenomena with major societal impact and a variety of sub-optimal behaviors and clinical conditions. Although it is well known that positive and negative affective states bear important cognitive/behavioral consequences, the effect of emotional experiences on decision-making remains unclear due to the existence of many conflicting results. Inspired by the need to understand if and to what extent the current COVID-19 pandemic has determined changes in our decision-making processes by means of the unusual, prolonged experience of negative feelings, in this study we investigate the effect of anger, fear, sadness, physical and moral disgust on intertemporal and risky choices. Results show that all emotions significantly increase subjects' preferences for immediate rewards over delayed ones, and for risky rewards over certain ones, in comparison to a "neutral emotion" condition, although the magnitude of the effect differs across emotions. In particular, we observed a more pronounced effect in the case of sadness and moral disgust. These findings contribute to the literature on emotions and decision-making by offering an alternative explanation to the traditional motivational appraisal theories. Specifically, we propose that the increased preference for immediate gratification and risky outcomes serves as a mechanism of self-reward aimed at down-regulating negative feelings and restore the individual's "emotional balance".

The relation between disgust sensitivity and risk-taking propensity: A domain specific approach

Disgust is a cross-culturally recognized emotion that is characterized by avoidant or cautious tendencies. Accordingly, greater sensitivity to disgust may be related to less willingness to take risks. Relatively little research has examined the association between disgust sensitivity and risk-taking propensity. Further, no research to date has taken a domain specific approach to understanding the association between these constructs. Across two studies (N1=98, N2=390) and a mini-meta analysis utilizing two additional datasets (total N=1981), we assessed the extent to which domain specific disgust sensitivity (i.e., Pathogen, Sexual, and Moral) were related to domain specific risk-taking propensity (i.e., Social, Recreational, Health/Safety, Ethical, and Financial). We conducted two cross-sectional studies, with a community and a student sample. Participants completed surveys that included measures of disgust sensitivity and risk-taking propensity. Bivariate correlations across the two studies indicated that greater disgust sensitivity was related to lower risk-taking propensity across almost all domains. However, when controlling for covariance among the disgust sensitivity domains, regression analyses suggested variability in the association between disgust sensitivity and risk-taking propensity depending on domains. Based on mini meta-analysis, sexual disgust sensitivity had the strongest relationships with social risk-taking propensity and health/safety risk-taking propensity, and moral disgust sensitivity had the strongest relationship with ethical risk-taking propensity. These findings suggest the presence of domain specific relations between disgust sensitivity and risk-taking propensity. The domain specific focus may help in utilizing disgust as a factor to decrease certain risky behaviors (e.g., moral disgust for decreasing plagiarism).

Social Perception of Risk-Taking Willingness as a Function of Expressions of Emotions

Two studies showed that emotion expressions serve as cues to the expresser's willingness to take risks in general, as well as in five risk domains (ethical, financial, health and safety, recreational, and social). Emotion expressions did not have a uniform effect on risk estimates across risk domains. Rather, these effects fit behavioral intentions associated with each emotion. Thus, anger expressions were related to ethical and social risks. Sadness reduced perceived willingness to take financial (Study 1 only), recreational, and social risks. Happiness reduced perceived willingness to take ethical and health/safety risks relative to neutrality. Disgust expressions increased the perceived likelihood of taking a social risk. Finally, neutrality increased the perceived willingness to engage in risky behavior in general. Overall, these results suggest that observers use their naïve understanding of the meaning of emotions to infer how likely an expresser is to engage in risky behavior.

The multidimensional nature of food neophobia

People vary in their willingness to try new foods. This variation, which is most frequently measured using the Food Neophobia Scale (FNS; Pliner & Hobden, 1992), has been interpreted as unidimensional. In four studies (N's = 210, 306, 160, and 161), we 1) demonstrate that food neophobia varies across meat and plant dimensions, 2) explore the validity of a measure of meat and plant neophobia, and 3) test whether these food neophobia dimensions predict decisions to eat a novel food item (i.e., a snack bar that contains insects). Mixed-effects model across the four studies indicated that the two dimensions differentially relate to a number of variables, including disgust sensitivity, animal empathy, and masculinity. Women scored higher on meat neophobia than men, but the sexes did not differ on plant neophobia. Only meat neophobia uniquely predicted eating a novel insect-based snack bar. Overall, these results extend knowledge regarding orientations toward novel foods.

Infection threat shapes our social instincts

We social animals must balance the need to avoid infections with the need to interact with conspecifics. To that end we have evolved, alongside our physiological immune system, a suite of behaviors devised to deal with potentially contagious individuals. Focusing mostly on humans, the current review describes the design and biological innards of this behavioral immune system, laying out how infection threat shapes sociality and sociality shapes infection threat. The paper shows how the danger of contagion is detected and posted to the brain; how it affects individuals’ mate choice and sex life; why it strengthens ties within groups but severs those between them, leading to hostility toward anyone who looks, smells, or behaves unusually; and how it permeates the foundation of our moral and political views. This system was already in place when agriculture and animal domestication set off a massive increase in our population density, personal connections, and interaction with other species, amplifying enormously the spread of disease. Alas, pandemics such as COVID-19 not only are a disaster for public health, but, by rousing millions of behavioral immune systems, could prove a threat to harmonious cohabitation too.

Gendered outgroup prejudice: An evolutionary threat management perspective on anti-immigrant bias

Are male and female immigrants viewed similarly or differently? Consistent with an evolutionary threat management perspective, we suggest that the answer to this question depends upon what types of threats immigrant groups are perceived as posing. In the present study, we compared attitudes toward male and female immigrants from either a violent ecology (e.g., Syria) or a pathogen-rich ecology (e.g., Liberia). We hypothesized that people would have more negative attitudes toward male than female immigrants from a violent ecology, but that attitudes would be similar toward male and female immigrants from a pathogen-rich ecology. Internal meta-analyses of three studies (total N = 1,488) were in line with our hypothesis. They showed that attitudes toward male immigrants from a violent ecology were more negative than attitudes toward female immigrants from the same ecology. In contrast, attitudes toward male and female immigrants were similar when those immigrants came from a pathogen-rich ecology. Our findings are consistent with an evolutionary threat management perspective on outgroup prejudice and are aligned with the male warrior hypothesis: Attitudes toward male versus female outgroup members vary with the potential threats these outgroups pose.

Differential effects of progesterone on social recognition and the avoidance of pathogen threat by female mice

Although pathogen threat affects social and sexual responses across species, relatively little is known about the underlying neuroendocrine mechanisms. Progesterone has been speculated to be involved in the mediation of pathogen disgust in women, though with mixed experimental support. Here we considered the effects of acute progesterone on the disgust-like avoidance responses of female mice to pathogen threat. Estrous female mice discriminated and avoided the urinary and associated odors of males subclinically infected with the murine nematode parasite, Heligmosomoides polygyrus. These avoidance responses were not significantly affected by pre-treatment with progesterone. Likewise, brief (1 min) exposure to the odors of infected males attenuated the subsequent responses of females to the odors of the normally preferred unfamiliar males and enhanced their preferences for familiar males. Neither progesterone nor allopregnanolone, a central neurosteroid metabolite of progesterone, had any significant effects on the avoidance of unfamiliar males elicited by pre-exposure to a parasitized male. Progesterone and allopregnanolone, did, however, significantly attenuate the typical preferences of estrous females for unfamiliar uninfected males, suggestive of effects on social recognition. These findings with mice indicate that progesterone may have minimal effects on the responses to specific parasite threat and the expression of pathogen disgust but may influence more general social recognition and preferences.

Pathogens, odors, and disgust in rodents

All animals are under the constant threat of attack by parasites. The mere presence of parasite threat can alter behavior before infection takes place. These effects involve pathogen disgust, an evolutionarily conserved affective/emotional system that functions to detect cues associated with parasites and infection and facilitate avoidance behaviors. Animals gauge the infection status of conspecific and the salience of the threat they represent on the basis of various sensory cues. Odors in particular are a major source of social information about conspecifics and the infection threat they present. Here we briefly consider the origins, expression, and regulation of the fundamental features of odor mediated pathogen disgust in rodents. We briefly review aspects of: (1) the expression of affective states and emotions and in particular, disgust, in rodents; (2) olfactory mediated recognition and avoidance of potentially infected conspecifics and the impact of pathogen disgust and its' fundamental features on behavior; (3) pathogen disgust associated trade-offs; (4) the neurobiological mechanisms, and in particular the roles of the nonapeptide, oxytocin, and steroidal hormones, in the expression of pathogen disgust and the regulation of avoidance behaviors and concomitant trade-offs. Understanding the roles of pathogen disgust in rodents can provide insights into the regulation and expression of responses to pathogens and infection in humans.

Slimy worms or sticky kids How caregiving tasks and gender identity attenuate disgust response

Disgust is derived from evolutionary processes to avoid pathogen contamination. Theories of gender differences in pathogen disgust utilize both evolutionary psychological and sociocultural perspectives. Drawing on research that suggests that masculine and feminine gender identities are somewhat orthogonal, we examine how gender identity intersects with pathogen disgust. In addition, building on evolutionary psychological and sociocultural accounts of how caregiving and parental investment affect pathogen disgust, we present a new measure of caregiving disgust and compare its properties across gender, parental status, and political ideology with those of a conventional pathogen disgust measure. This registered report finds that how masculinity and femininity affect disgust varies by gender, disgust domain, and their intersection; that parental status effects vary by disgust domain but not gender; that reframing disgust in terms of caregiving eliminates the gender gap in disgust; and that the caregiving frame unexpectedly strengthens the relationship between disgust and political ideology.

The Emotion of Disgust among Medical and Psychology Students

The emotion of disgust evolved as a way to protect oneself from illness and is associated with aspects of disease avoidance. Disgust Scale–Revised (DS-R) (Olatunji et al., 2008) measures the disgust propensity of three kinds of disgust (core, animal reminder, contamination). Contextual factors, such as academic background, might influence DS-R scoring, especially among medical students, where the notion of disease is central. We examined DS-R scoring and the choice of postgraduate studies in medical (n = 94) and psychology (n = 97) students. In an anonymous web-based survey, participants completed the DS-R and a questionnaire including plans for postgraduate studies. Females outnumbered males and scored higher in total DS-R score (p = 0.003). Psychology students scored higher in all three kinds of disgust (p < 0.001 for core disgust and animal reminder, p = 0.069 for contamination disgust), indicating a higher level of disease avoidance. Medical students willing to follow Internal Medicine scored higher in core disgust (p < 0.05), while psychology students willing to study Experimental Psychology scored lower in the animal reminder subscale (p = 0.019 and p < 0.001 for the association between these subscales and the orientation of Medical and Psychology Students, respectively). In conclusion, disgust propensity as rated by DS-R is related to academic background and orientation preferences in postgraduate studies.

Keep your (social) distance: Pathogen concerns and social perception in the time of COVID-19

Previous research suggests that individual differences in pathogen disgust sensitivity and social anxiety predict avoidance behavior, especially of pathogen cues, and reduced tolerance for social ambiguity. Conversely, generalized social trust is associated with approach behavior and a greater tolerance for social ambiguity. We conducted an online study (N = 1078) to test these predictions in the context of the COVID-19 global pandemic. Specifically, we assessed whether individual differences in pathogen disgust sensitivity, social anxiety and generalized social trust predicted judgments of trustworthiness, desired social distance and perceptions of sickness of target faces wearing surgical masks. Our results showed that (a) high sensitivity to pathogen disgust predicted lower judgments of trustworthiness and lower social desirability; (b) high social anxiety predicted higher perceptions of illness and lower judgments of trustworthiness; and (c) generalized social trust predicted higher judgments of trustworthiness and lower perceptions of illness of target faces. Further, we found that mask wearers were perceived as more likely to be ill, more trustworthy and more socially desirable than the same faces presented to a control group, without the surgical mask superimposed. Results are discussed in terms of perceived compliance with an emerging social norm overriding the intrinsic untrustworthiness of masked faces.

A Proximal Perspective on Disgust

The functional basis of disgust in disease avoidance is widely accepted; however, there is disagreement over what disgust is. This is a significant problem, as basic questions about disgust require knowing if single/multiple forms/processes exist. We address this issue with a new model with one form of disgust generated by multiple processes: (a) pure disgust experienced during gastrointestinal illness; (b) somatosensory disgust elicited by specific cues that activate the pure disgust state; (c) anticipatory disgust elicited by associations between distance cues for somatosensory disgust and requiring threat evaluation; (d) simulated disgusts elicited by imagining somatosensory and anticipatory disgust and frequently involving other emotions. Different contamination processes interlink (a–d). The implications of our model for fundamental questions about disgust (e.g., emotion status; continuation into animals) are examined.

The role of social cognition in parasite and pathogen avoidance

The acquisition and use of social information are integral to social behaviour and parasite/pathogen avoidance. This involves social cognition which encompasses mechanisms for acquiring, processing, retaining and acting on social information. Social cognition entails the acquisition of social information about others (i.e. social recognition) and from others (i.e. social learning). Social cognition involves assessing other individuals and their infection status and the pathogen and parasite threat they pose and deciding about when and how to interact with them. Social cognition provides a framework for examining pathogen and parasite avoidance behaviours and their associated neurobiological mechanisms. Here, we briefly consider the relationships between social cognition and olfactory-mediated pathogen and parasite avoidance behaviours. We briefly discuss aspects of (i) social recognition of actual and potentially infected individuals and the impact of parasite/pathogen threat on mate and social partner choice; (ii) the roles of 'out-groups' (strangers, unfamiliar individuals) and 'in-groups' (familiar individuals) in the expression of parasite/pathogen avoidance behaviours; (iii) individual and social learning, i.e. the utilization of the pathogen recognition and avoidance responses of others; and (iv) the neurobiological mechanisms, in particular the roles of the nonapeptide, oxytocin and steroid hormones (oestrogens) associated with social cognition and parasite/pathogen avoidance.This article is part of the Theo Murphy meeting issue 'Evolution of pathogen and parasite avoidance behaviours'.

State-dependent risk-taking

Who takes risks, and when? The relative state model proposes two non-independent selection pressures governing risk-taking: need-based and ability-based. The need-based account suggests that actors take risks when they cannot reach target states with low-risk options (consistent with risk-sensitivity theory). The ability-based account suggests that actors engage in risk-taking when they possess traits or abilities that increase the expected value of risk-taking (by increasing the probability of success, enhancing payoffs for success or buffering against failure). Adaptive risk-taking involves integrating both considerations. Risk-takers compute the expected value of risk-taking based on their state-the interaction of embodied capital relative to one's situation, to the same individual in other circumstances or to other individuals. We provide mathematical support for this dual pathway model, and show that it can predict who will take the most risks and when (e.g. when risk-taking will be performed by those in good, poor, intermediate or extreme state only). Results confirm and elaborate on the initial verbal model of state-dependent risk-taking: selection favours agents who calibrate risk-taking based on implicit computations of condition and/or competitive (dis)advantage, which in turn drives patterned individual differences in risk-taking behaviour.

Psychometric Properties, Factor Structure, and Evidence for Measurement Invariance in the Greek Version of the Disgust Scale-Revised (DS-R)

The Disgust Scale has been designed to measure disgust propensity—the individual ease in experiencing disgust. The present study aimed to explore the validity, reliability, the factor structure, and the measurement invariance of the Greek version of the Disgust Scale-Revised (DS-R). A sample of 754 healthy participants completed the Greek version of the DS-R. A subset (n = 363) also completed the revised Symptom checked list and the Eysenck Personality Questionnaire, in order to examine the concurrent validity. Exploratory and Confirmatory factor analyses in different subsets were used to examine the factor structure. Multiple indicators–multiple causes model (MIMIC) models were used to assess the measurement invariance across gender and age. Demographic influences were assessed using t-tests, ANOVA, and Pearson’s correlations. Exploratory factor analysis concluded to two and three factor models, with a factor structure similar to the ones proposed in the literature. Confirmatory factor analysis and bi-factor analysis provided evidence in favor of the three-factor solution. Measurement invariance test revealed differences in six items across gender, and three items across age. The psychometric properties of the factors were satisfactory. Demographic influences on the responses were present, especially with respect to gender. The Greek version of the DS-R demonstrated satisfactory psychometric properties, making it suitable for use for the Greek population.

The source effect as a natural function of disgust in interpersonal context and its impairment in mental disorders

Disgust affects interpersonal relationships and regulates hygienic, sexual and distance behaviour. Its intensity in the interpersonal context depends on the character of the relationship. Strangers normally evoke more disgust than intimates (known as the source effect). General disgust sensitivity is increased in various mental diseases. It is unclear how disgust in the interpersonal context is affected and whether the source effect is preserved. 460 inpatients with mental disorders and 463 healthy subjects answered a newly developed Questionnaire (DIRQ) that covers disgust in the interpersonal context on content categories (hygiene, physical proximity, sexuality) and on source categories (self, partner, parent, stranger). Mental disorders were diagnosed with structured interviews. Healthy controls exhibited a pronounced source effect, with strangers evoking more disgust than intimates. In patients, this source effect was reduced (Cohen's d = 0.3), especially for sexual disgust, while general disgust sensitivity was increased (d = 0.5). High disgust in patients was best predicted by a history of sexual abuse and by the presence of post-traumatic stress disorder. In conclusion, mentally impaired patients show increased and trauma-associated disgust sensitivity. Their downregulation of sexual disgust in intimate relationships is hindered, which may have a boundary protective function but might also fuel difficulties engaging in relationships or intimacy.

PsychoBehavioroimmunology: Connecting the Behavioral Immune System to Its Physiological Foundations

Although infectious disease has posed a significant and persistent threat to human survival and welfare throughout history, only recently have the psychological and behavioral implications of disease threat become a topic of research within the behavioral sciences. This growing body of work has revealed a suite of affective and cognitive processes that motivate the avoidance of disease-causing objects and situations—a cascade of processes loosely conceptualized as a “behavioral immune system (BIS).” Recent BIS research has linked disease threat to a surprisingly broad set of psychological and behavioral phenomena. However, research examining how the BIS is nested within our broader physiology is only beginning to emerge. Here, we review research that has begun to elucidate the physiological foundations of the BIS—at the levels of sensory modalities, cells, and genes. We also discuss the future of this work.