Megan J. Oaten

Disgust as a disease-avoidance mechanism

Many researchers have claimed that the emotion of disgust functions to protect us from disease. Although there have been several discussions of this hypothesis, none have yet reviewed the evidence in its entirety. The authors derive 14 hypotheses from a disease-avoidance account and evaluate the evidence for each, drawing upon research on pathogen avoidance in animals and empirical research on disgust. In all but 1 case, the evidence favors a disease-avoidance account. It is suggested that disgust is evoked by objects/people that possess particular types of prepared features that connote disease. Such simple disgust are directly disease related, are acquired during childhood, and are able to contaminate other objects/people. The complex disgust, which emerge later in development, may be mediated by several emotions. In these cases, violations of societal norms that may subserve a disease-avoidance function, notably relating to food and sex, act as reminders of simple disgust elicitors and thus generate disgust and motivate compliance. The authors find strong support for a disease-avoidance account and suggest that it offers a way to bridge the divide between concrete and ideational accounts of disgust.

Self-regulatory failure and intimate partner violence perpetration

Five studies tested the hypothesis that self-regulatory failure is an important predictor of intimate partner violence (IPV) perpetration. Study 1 participants were far more likely to experience a violent impulse during conflictual interaction with their romantic partner than they were to enact a violent behavior, suggesting that self-regulatory processes help individuals refrain from perpetrating IPV when they experience a violent impulse. Study 2 participants high in dispositional self-control were less likely to perpetrate IPV, in both cross-sectional and residualized-lagged analyses, than were participants low in dispositional self-control. Study 3 participants verbalized more IPV-related cognitions if they responded immediately to partner provocations than if they responded after a 10-s delay. Study 4 participants whose self-regulatory resources were experimentally depleted were more violent in response to partner provocation (but not when unprovoked) than were nondepleted participants. Finally, Study 5 participants whose self-regulatory resources were experimentally bolstered via a 2-week training regimen exhibited less violent inclinations than did participants whose self-regulatory resources had not been bolstered. These findings hint at the power of incorporating self-regulation dynamics into predictive models of IPV perpetration.

Longitudinal gains in self-regulation from regular physical exercise.

OBJECTIVES The purpose of the present study was to test whether the repeated practice of self-regulation could improve regulatory strength over time. METHOD Regulatory performance was assessed at baseline, then at monthly intervals for a period of 4 months using a visual tracking task. Perceived stress, emotional distress, self-efficacy and general regulatory behaviour were assessed by questionnaire. Following a 2-month control phase, participants entered a 2-month self-regulation programme designed to increase regulatory strength: a programme of regular physical exercise. RESULTS Relative to the control phase, participants who exercised showed significant improvement in self-regulatory capacity as measured by an enhanced performance on the visual tracking task following a thought-suppression task. During the regulatory exercise phase, participants also reported significant decreases in perceived stress, emotional distress, smoking, alcohol and caffeine consumption, and an increase in healthy eating, emotional control, maintenance of household chores, attendance to commitments, monitoring of spending and an improvement in study habits. The control phase showed no systematic changes in performance on the visual tracking task across sessions. Reports of perceived stress, emotional distress and regulatory behaviours were also stable across sessions. CONCLUSIONS The uptake and maintenance of an exercise programme over a 2-month period produced significant improvements in a wide range of regulatory behaviours. Nearly every major personal and social problem has some degree of regulatory failure. The idea that the capacity for self-regulation can be improved is therefore of vast practical importance.

Improved Self-Control: The Benefits of a Regular Program of Academic Study

Academic examination stress impairs regulatory behavior by consuming self-control strength (Oaten & Cheng, 2005). In this study, we tested whether a study intervention program, a form of repeated practice of self-control, could improve regulatory strength and dampen the debilitating effects of exam stress. We assessed 2 cohorts at baseline and again at the commencement of exams. Without any intervention, we replicated our previous findings of deteriorations in regulatory behaviors at exam time. Students receiving the study program, however, showed significant improvement in self-regulatory capacity as shown by an enhanced performance on a visual tracking task following a thought-suppression task. During examinations, these participants also reported significant decreases in smoking, alcohol, and caffeine consumption and an increase in healthy eating, emotional control, maintenance of household chores, attendance to commitments, monitoring of spending, and an improvement in study habits. Hence, the study program not only overcame deficits caused by exam stress but actually led to improvements in self-control even during exam time.

Children's response to adult disgust elicitors: development and acquisition.

Little is known about when or how different disgust elicitors are acquired. In Study 1, parents of children (0-18 years old) rated how their child would react to 22 disgust elicitors. Different developmental patterns were identified for core, animal, and sociomoral elicitors, with core elicitors emerging first. In Study 2, children (2-16 years old) were exposed alone and then with their parent to a range of elicitors derived from Study 1. Self-report, behavioral, and facial expression data were obtained along with measures of contagion, conservation, and contamination. Convergent evidence supported the developmental patterns reported in Study 1. Evidence for parent-child transmission was also observed, with parents of young children emoting more disgust to their offspring and showing greater behavioral avoidance. Moreover, child reactivity to animal and sociomoral elicitors and contamination correlated with parental responsiveness. Finally, young children who failed to demonstrate contagion and conservation knowledge were as reactive to core elicitors and contamination as children of the same age who demonstrated such knowledge. These findings are interpreted within an evolutionary framework in which core disgust responses are acquired early to promote avoidance of pathogens.

Can the emotion of disgust be harnessed to promote hand hygiene? Experimental and field-based tests

Two studies carried out in Sydney, Australia explored whether inducing disgust may be a useful addition to hand-hygiene interventions. Experiment 1 employed a novel laboratory measure of hand hygiene, and tested whether a brief (3-min) video-based intervention using disgust/education, improved hand hygiene relative to education alone and a control condition. On test, a week later, the disgust intervention significantly exceeded the education and control condition combined, although the effect size was modest. Experiment 2 examined the generality of this effect in a field study. During a baseline period, soap and paper towel use in a series of washrooms were covertly monitored. This was followed by an intervention period, in which two washrooms received disgust/education-based posters and a further two, educational posters, exhorting participants to wash their hands. A follow-up period, after the posters were removed, was also monitored. The disgust-based intervention was significantly better at promoting hand hygiene. These findings suggest that even brief disgust-based interventions may be successful and that these can be tested and developed under laboratory conditions.

The effect of appropriate and inappropriate stimulus color on odor discrimination

Color can strongly affect participants’ self-report of an odor’s qualities. In Experiment 1, we examined whether color influences a more objective measure of odor quality, discrimination. Odor pairs, presented in their appropriate color (e.g., strawberry and cherry in red water), an inappropriate color (e.g., strawberry and cherry in green water), or uncolored water were presented for discrimination. Participants made significantly more errors when odors were discriminated in an inappropriate color. In Experiment 2, the same design was utilized, but with an articulatory suppression task (AST), to examine whether the effect of color was mediated by identification or by a more direct effect on the percept. Here, the AST significantly improved discrimination for the inappropriate color condition, relative to Experiment 1. Although color does affect a more objective measure of odor quality, this is mediated by conceptual, rather than perceptual, means.

Effect of self-reported sexual arousal on responses to sex-related and non-sex-related disgust cues.

Prior to and during sexual intercourse, people are exposed to stimuli that in other contexts might act as disgust-eliciting cues. This study examined whether sexual arousal, in contrast to general arousal, could selectively reduce reported disgust for cues that pilot participants identified as sex or non-sex related. Male undergraduates were randomly assigned to one of four viewing groups. One group viewed erotic female images, a second clad female images, a third pleasantly arousing images (e.g., skydiving), and a fourth unpleasantly arousing images (e.g., an aimed gun). After the viewing phase, all participants were exposed to pairs of real disgust elicitors (sex versus non-sex related) drawn from various sensory modalities. Participants in the erotic images group, who rated being more sexually aroused than those in the other three groups, also reported being significantly less disgusted by sex-related elicitors. While the mechanism for this effect is not currently known, our findings suggest one plausible explanation for risky sexual behavior as well as having implications for the role of disgust in sexual dysfunction.

Disease avoidance as a functional basis for stigmatization

Stigmatization is characterized by chronic social and physical avoidance of a person(s) by other people. Infectious disease may produce an apparently similar form of isolation—disease avoidance—but on symptom remission this often abates. We propose that many forms of stigmatization reflect the activation of this disease-avoidance system, which is prone to respond to visible signs and labels that connote disease, irrespective of their accuracy. A model of this system is presented, which includes an emotional component, whereby visible disease cues directly activate disgust and contamination, motivating avoidance, and a cognitive component, whereby disease labels bring to mind disease cues, indirectly activating disgust and contamination. The unique predictions of this model are then examined, notably that people who are stigmatized evoke disgust and are contaminating. That animals too show avoidance of diseased conspecifics, and that disease-related stigma targets are avoided in most cultures, also supports this evolutionary account. The more general implications of this approach are then examined, notably how it can be used to good (e.g. improving hygiene) or bad (e.g. racial vilification) ends, by yoking particular labels with cues that connote disease and disgust. This broadening of the model allows for stigmatization of groups with little apparent connection to disease.

The effect of disgust on oral immune function

Disgust motivates avoidance of pathogen sources, but whether its role in disease avoidance extends into activating the immune system is unexplored. This was tested here by comparing oral immune markers before and after a disgust induction, relative to neutral and negative induction control groups. The disgust group, but not controls, revealed an oral inflammatory response, with increased salivary tumor necrotizing factor alpha and albumin, as well as a down-regulation of immunoglobulin A (SIgA) secretion. It has been hypothesized that disgust evolved in animals to clear toxins from the oral cavity by gaping and increased salivary flow. Our data suggest down-regulated SIgA secretion may be a vestige of this response so as to conserve protein, while the inflammatory reaction may reflect an adaptive response to disease threat, selectively triggered by disgust. The broader implications of these data for a discrete neuro-gut-immune axis are examined.