Social neuroscience of disgust

Abstract

Disgust can be thought of as an affective system that has evolved to detect signs of pathogens, parasite and toxins as well as to stimulate behaviors that reduce the risk of their acquisition. Disgust incorporates social cognitive mechanisms to regulate exposure to and, or anticipate and avoid exposure to pathogens and toxins. Social cognition entails the acquisition of social information about others (ie, social recognition) and from others (ie, social learning). This involves recognizing and assessing other individuals and the pathogen/parasite/contamination/toxin threat they pose and deciding about when and how to interact with and, or avoid them. Social cognition provides a frame-work for examining the expression of disgust and the associated neurobiological mechanisms. Here, we briefly consider the relations between social cognition and pathogen/parasite/toxin avoidance behaviors. We briefly discuss aspects of: (1) the odor mediated social recognition of actual and potentially infected individuals and the impact of parasite/pathogen threat on disgust mate and social partner choice; (2) the roles of "out-groups" (strangers, unfamiliar individuals) and "in-groups" (familiar individuals) in the expression of disgust and pathogen avoidance behaviors; (3) individual and social learning of disgust and empathy for disgust; (4) toxin elicited disgust and anticipatory disgust; (5) the neurobiological mechanisms, and in particular the roles of the nonapeptide, oxytocin and estrogenic mechanism associated with social cognition and the expression of disgust. These findings on the social neuroscience of disgust have a direct bearing on our understanding of the roles of disgust in shaping human and nonhuman social behavior.

Pathogens, odors, and disgust in rodents

“…killing the host) and indirect non-consumptive effects (non-lethal “risk effects”) ( Buck, 2019 ; Buck et al, 2018 ). The indirect non-consumptive effects are the physiological and neurobiological costs associated with the expression of disgust and the detection of parasites and avoidance of infection ( Buck et al, 2018 ; Kavaliers et al, 2019 ). Without even infecting their hosts parasites can have a diverse range of motivational, behavioral (social and non-social), and neurobiological actions.…”

“…However, disgust is also elicited by a variety of external threats (e.g. ectoparasites, contaminated feces) and fear (and associated anxiety and stress) can contribute to the behavioral and neurobiological responses to parasite and infection threat ( Kavaliers et al, 2019 ). Intrinsic to both disgust and fear is also neophobia and the avoidance of novel and unfamiliar environmental and social situations under what are perceived as threat conditions.…”

“…Copying of the avoidance of infected males displayed by other females is also evident. Female mice avoid males that are associated with the odor cues of either infected females or infected males ( Kavaliers et al, 2019 ). Male mice housed with a sick (LPS treated) individual take on aspects of the sick animal’s odor and odorant profile, reducing their own social attractiveness ( Gervasi et al, 2018 ).…”

“…Sex differences in pathogen avoidance behaviors may vary across modes of pathogen exposure. Females may be more susceptible to exposure to direct sexually acquired infection, exhibiting stronger avoidance/aversive behaviors and hygenic behaviors and greater disgust when confronted with infectious conspecifics ( Kavaliers et al, 2019a ; Poirotte and Kappeler, 2019 ; Poirotte et al, 2017 ). Superimposed on this is a lower risk taking by females with females prioritizing the avoidance of negative outcomes over seeking positive.…”

The neuroscience and genomics of social behavior

“…Indeed, one consequence of an inability to gather information about environmental threats by observing others is that it could impair the capacity for recognizing and responding to potential dangers from a position of relative safety. Kavaliers et al 7 argue that this form of social cognition forms the basis of the affective response we as humans experience as disgust. This seems highly plausible given we typically experience disgust in reaction to stimuli that could potentially do us harm through, for example, poisoning or infection.…”