Disgust is an emotional response of revulsion to something considered offensive, distasteful, or unpleasant. In The Expression of the Emotions in Man and Animals, Charles Darwin wrote that disgust is a sensation that refers to something revolting. Disgust is experienced primarily in relation to the sense of taste (either perceived or imagined), and secondarily to anything which causes a similar feeling by sense of smell, touch, or vision. Musically sensitive people may even be disgusted by the cacophony of inharmonious sounds. Research continually has proven a relationship between disgust and anxiety disorders such as arachnophobia, blood-injection-injury type phobias, and contamination fear related obsessive–compulsive disorder (also known as OCD).
Disgust is one of the basic emotions of Robert Plutchik's theory of emotions and has been studied extensively by Paul Rozin. It invokes a characteristic facial expression, one of Paul Ekman's six universal facial expressions of emotion. Unlike the emotions of fear, anger, and sadness, disgust is associated with a decrease in heart rate.
== Evolutionary significance == It is believed that the emotion of disgust has evolved as a response to offensive foods that may cause harm to the organism. A common example of this is found in human beings who show disgust reactions to mouldy milk or contaminated meat. Disgust appears to be triggered by objects or people who possess attributes that signify disease.
Self-report and behavioural studies found that disgust elicitors include: * body products (feces, urine, vomit, sexual fluids, saliva, and mucus); * foods (spoiled foods); * animals (fleas, ticks, lice, cockroaches, worms, flies, rats, and mice); * hygiene (visible dirt and "inappropriate" acts [e.g., using an unsterilized surgical instrument]); * body envelope violations (blood, gore, and mutilation); * death (dead bodies and organic decay); * visible signs of infection
The above-mentioned main disgust stimuli are similar to one another in the sense that they can all potentially transmit infections, and are the most common referenced elicitors of disgust cross-culturally. Because of this, disgust is believed to have evolved as a component of a behavioral immune system in which the body attempts to avoid disease-carrying pathogens in preference to fighting them after they have entered the body. This behavioral immune system has been found to make sweeping generalizations because "it is more costly to perceive a sick person as healthy than to perceive a healthy person as sickly". Researchers have found that sensitivity to disgust is negatively correlated to aggression because feelings of disgust typically bring about a need to withdraw while aggression results in a need to approach. This can be explained in terms of each of the types of disgust. For those especially sensitive to moral disgust, they would want to be less aggressive because they want to avoid hurting others. Those especially sensitive to pathogen disgust might be motivated by a desire to avoid the possibility of an open wound on the victim of the aggression; however, for those sensitive to sexual disgust, some sexual object must be present for them to be especially avoidant of aggression.
Research has also found that people who are more sensitive to disgust tend to find their own in-group more attractive and tend to have more negative attitudes toward other groups. This may be explained by assuming that people begin to associate outsiders and foreigners with disease and danger while simultaneously associating health, freedom from disease, and safety with people similar to themselves.
Taking a further look into hygiene, disgust was the strongest predictor of negative attitudes toward obese individuals. A disgust reaction to obese individuals was also connected with views of moral values.
=== Domains of disgust===
Tybur, et al., outlines three domains of disgust: pathogen disgust, which "motivates the avoidance of infectious microorganisms"; sexual disgust, "which motivates the avoidance of [dangerous] sexual partners and behaviors"; and moral disgust, which motivates people to avoid breaking social norms. Disgust may have an important role in certain forms of morality.
Pathogen disgust arises from a desire to survive and, ultimately, a fear of death. He compares it to a "behavioral immune system" that is the 'first line of defense' against potentially deadly agents such as dead bodies, rotting food, and vomit.
Sexual disgust arises from a desire to avoid "biologically costly mates" and a consideration of the consequences of certain reproductive choices. The two primary considerations are intrinsic quality (e.g., body symmetry, facial attractiveness, etc.) and genetic compatibility (e.g., avoidance of inbreeding such as the incest taboo).
Moral disgust "pertains to social transgressions" and may include behaviors such as lying, theft, murder, and rape. Unlike the other two domains, moral disgust "motivates avoidance of social relationships with norm-violating individuals" because those relationships threaten group cohesion.
=== Gender differences === Women generally report greater disgust than men, especially regarding sexual disgust or general repulsiveness which have been argued to be consistent with women being more selective regarding sex for evolutionary reasons.
Sensitivity to disgust rises during pregnancy, along with levels of the hormone progesterone. Scientists have conjectured that pregnancy requires the mother to "dial down" her immune system so that the developing embryo won't be attacked. To protect the mother, this lowered immune system is then compensated by a heightened sense of disgust.
Because disgust is an emotion with physical responses to undesirable or dirty situations, studies have proven there are cardiovascular and respiratory changes while experiencing the emotion of disgust.
As mentioned earlier, women experience disgust more prominently than men. This is reflected in a study about dental phobia. A dental phobia comes from experiencing disgust when thinking about the dentist and all that entails. 4.6 percent of women compared to 2.7 percent of men find the dentist disgusting.
== Body language == In a series of significant studies by Paul Ekman in the 1970s, it was discovered that facial expressions of emotion are not culturally determined, but universal across human cultures and thus likely to be biological in origin. The facial expression of disgust was found to be one of these facial expressions. This characteristic facial expression includes slightly narrowed brows, a curled upper lip, wrinkling of the nose and visible protrusions of the tongue, although different elicitors may produce different forms of this expression. It was found that the facial expression of disgust is readily recognizable across cultures. This facial expression is also produced in blind individuals and is correctly interpreted by individuals born deaf.
The mirror-neuron matching system found in monkeys and humans is a proposed explanation for such recognition, and shows that our internal representation of actions is triggered during the observation of another’s actions. It has been demonstrated that a similar mechanism may apply to emotions. Seeing someone else's facial emotional expressions triggers the neural activity that would relate to our own experience of the same emotion. This points to the universality, as well as survival value of the emotion of disgust.
===Children's reactions to a face showing disgust=== At a very young age, children are able to identify different, basic facial emotions. If a parent makes a negative face and a positive emotional face toward two different toys, a child as young as five months would avoid the toy associated with a negative face. Young children tend to associate a face showing disgust with anger instead of being able to identify the difference. Adults, however, are able to make the distinction. The age of understanding seems to be around ten years old.
==Cultural differences== Because disgust is partially a result of social conditioning, there are differences among different cultures in the objects of disgust. Americans "are more likely to link feelings of disgust to actions that limit a person's rights or degrade a person's dignity" while Japanese people "are more likely to link feelings of disgust to actions that frustrate their integration into the social world".
In some cultures, such as Cambodia, Chinese in Southeast Asia, northern Manchu tribes along Amur River, Sambians in Papua New Guinea, Thailand, Telugus of India, Hawaii and other Pacific Islanders, briefly taking the penis of a male infant or toddler into one's mouth was considered a nonsexual form of affection or even a form of ritual, greeting, respect, parenting love, or lifesaving. It is especially a Chinese custom for grandmothers, mothers, and elder sisters to calm their babies with fellatio. It has been reported that modern Chinese mother perform fellatio to her moribund son as affection and means for lifesaving, because they culturally believe when penis is completely retracted into abdomen, that person dies. Chinese also consume human placenta as traditional Chinese medicine, which is considered disgusting in most cultures.
Disgust is one of the basic emotions recognizable across multiple cultures and is a response to something revolting typically involving taste or sight. Though different cultures find different things disgusting, the reaction to the grotesque things remains the same throughout each culture; people and their emotional reactions in the realm of disgust remain the same.
==Neural basis== The scientific attempts to map specific emotions onto underlying neural substrates dates back to the first half of the 20th century. Functional MRI experiments have revealed that the anterior insula in the brain is particularly active when experiencing disgust, when being exposed to offensive tastes, and when viewing facial expressions of disgust. The research has supported that there are independent neural systems in the brain, each handling a specific basic emotion. The insula has been shown by several studies to be the main neural correlate of the feeling of disgust both in humans and in macaque monkeys. The insula is activated by unpleasant tastes, smells, and the visual recognition of disgust in conspecific organisms.
The posterior insula is characterized by connections with auditory, somatosensory, and premotor areas, and is not related to the olfactory or gustatory modalities. The patients also reported having reduced sensations of disgust themselves. Furthermore, electrical stimulation of the anterior insula conducted during neurosurgery triggered nausea, the feeling of wanting to throw up and uneasiness in the stomach. Finally, electrically stimulating the anterior insula through implanted electrodes produced sensations in the throat and mouth that were "difficult to stand". However, insula activation was only significantly correlated with ratings of disgust, pointing to a specific role of this brain structure in the processing of disgust. In another intensive fMRI study by Wicker & colleagues (2003), disgust reactions to visual and olfactory stimuli were compared. The study consisted of four runs and in the visual runs participants viewed movies of individuals smelling the contents of a glass (conditions: disgusting, pleasant, or neutral) and expressing the facial expressions of the respective emotions. The inability to recognize expressions of disgust appears in carriers of the Huntington gene before other symptoms appear. People with Huntington's disease are impaired at recognition of anger and fear, and experience a notably severe problem with disgust recognition.
===Major depressive disorder=== Patients suffering from major depression have been found to display greater brain activation to facial expressions of disgust.
=== Obsessive-compulsive disorder === The emotion of disgust may have an important role in understanding the neurobiology of obsessive-compulsive disorder (OCD), particularly in those with contamination preoccupations. In a study by Shapira & colleagues (2003), eight OCD subjects with contamination preoccupations and eight healthy volunteers viewed pictures from the International Affective Picture System during f-MRI scans. OCD subjects showed significantly greater neural responses to disgust-invoking images, specifically in the right insula. Furthermore, Sprengelmeyer (1997) found that the brain activation associated with disgust included the insula and part of the gustatory cortex that processes unpleasant tastes and smells. OCD subjects and healthy volunteers showed activation patterns in response to disgust pictures that differed significantly at the right insula. In contrast, the two groups were similar in their response to threat-inducing pictures, with no significant group differences at any site.
== Animal research == With respect to studies using rats, prior research of signs of a conditioned disgust response have been experimentally verified by Grill and Norgren (1978) who developed a systematic test to assess palatability. The Taste Reactivity (TR) test has thus become a standard tool in measuring disgust response. When given a stimulus intraorally which had been previously paired with a nausea-inducing substance, rats will show conditioned disgust reactions. "Gaping" in rats is the most dominant conditioned disgust reaction and the muscles used in this response mimic those used in species capable of vomiting. Recent studies have shown that treatments that reduced serotonin availability or that activate the endocannabinoid system can interfere with the expression of a conditioned disgust reaction in rats. These researchers showed that as nausea produced conditioned disgust reactions, by administering the rats with an antinausea treatment they could prevent toxin-induced conditioned disgust reactions. Furthermore, in looking at the different disgust and vomiting reactions between rats and shrews the authors showed that these reactions (particularly vomiting) play a crucial role in the associative processes that govern food selection across species.
In discussing specific neural locations of disgust, research has shown that forebrain mechanisms are necessary for rats to acquire conditioned disgust for a specific emetic (vomit-inducing) substance (such as lithium chloride). Other studies have shown that lesions to the area postrema and the parabrachial nucleus of the pons but not the nucleus of the solitary tract
==Morality== Although disgust was first thought to be a motivation for humans to only physical contaminants, it has since been applied to moral and social moral contaminants as well. The similarities between these types of disgust can especially be seen in the way people react to the contaminants. For example, if someone stumbles upon a pool of vomit, he/she will do whatever possible to place as much distance between himself/herself and the vomit as possible, which can include pinching the nose, closing the eyes, or running away. Likewise, when a group experiences someone who cheats, rapes, or murders another member of the group, its reaction is to shun or expel that person from the group.
Jones & Fitness (2008) From this, moral intuitions are believed to be stimulated prior to conscious moral cognitions which correlates with having a greater influence on moral judgments. However, additional studies have found the reverse effect, and recent studies have suggested that the average effect of disgust on moral judgments is small or absent. Potentially reconciling these effects, a study recently indicated that the direction and size of the effect of disgust stimuli on moral judgment depends upon an individual's sensitivity to disgust.
The effect also seems to be limited to a certain aspect of morality. Horberg et al. found that disgust plays a role in the development and intensification of moral judgments of purity in particular. In other words, the feeling of disgust is often associated with a feeling that some image of what is pure has been violated. For example, a vegetarian might feel disgust after seeing another person eating meat because he/she has a view of vegetarianism as the pure state-of-being. When this state-of-being is violated, the vegetarian feels disgust. Furthermore, disgust appears to be uniquely associated with purity judgments, not with what is just/unjust or what is harmful/caregiving, while other emotions such as fear, anger, and sadness are "unrelated to moral judgments of purity".
Some other research suggests that an individual’s level of disgust sensitivity is due to their particular experience of disgust.
===Political orientation=== In one study, people of differing political persuasions were shown disgusting images in a brain scanner. In conservatives, the basal ganglia and amygdala and several other regions showed increased activity, while in liberals other regions of the brain increased in activity. Both groups reported similar conscious reactions to the images. The difference in activity patterns was large: the reaction to a single image could predict a person's political leanings with 95% accuracy.
===Self-disgust=== Although limited research has been done on self-disgust, one study found that self-disgust and severity of moral judgments were negatively correlated. This is in contrast to findings related to disgust, which typically results in harsher judgments of transgressions. This implies that disgust directed towards the self functions very differently from disgust directed towards other people or objects. The origin of disgust can be defined by motivating the avoidance of offensive things, and in the context of a social environment, it can become an instrument of social avoidance.
== The Hydra's Tale: Imagining Disgust == According to the book The Hydra's Tale: Imagining Disgust by Robert Rawdon Wilson, disgust may be further subdivided into physical disgust, associated with physical or metaphorical uncleanliness, and moral disgust, a similar feeling related to courses of action. For example; "I am disgusted by the hurtful things that you are saying." Moral disgust should be understood as culturally determined; physical disgust as more universally grounded. The book also discusses moral disgust as an aspect of the representation of disgust. Wilson does this in two ways. First, he discusses representations of disgust in literature, film and fine art. Since there are characteristic facial expressions (the clenched nostrils, the pursed lips)—as Charles Darwin, Paul Ekman, and others have shown—they may be represented with more or less skill in any set of circumstances imaginable. There may even be "disgust worlds" in which disgust motifs so dominate that it may seem that entire represented world is, in itself, disgusting. Second, since people know what disgust is as a primary, or visceral, emotion (with characteristic gestures and expressions), they may imitate it. Thus, Wilson argues that, for example, contempt is acted out on the basis of the visceral emotion, disgust, but is not identical with disgust. It is a "compound affect" that entails intellectual preparation, or formatting, and theatrical techniques. Wilson argues that there are many such "intellectual" compound affects—such as nostalgia and outrage—but that disgust is a fundamental and unmistakable example. Moral disgust, then, is different from visceral disgust; it is more conscious and more layered in performance.
Wilson links shame and guilt to disgust (now transformed, wholly or partially, into self-disgust) primarily as a consequence rooted in self-consciousness. Referring to a passage in Doris Lessing's The Golden Notebook, Wilson writes that "the dance between disgust and shame takes place. A slow choreography unfolds before the mind's-eye."
Wilson examines the claims of several jurists and legal scholars—such as William Ian Miller—that disgust must underlie positive law. "In the absence of disgust", he observes, stating their claim, ". . . there would be either total barbarism or a society ruled solely by force, violence and terror." The moral-legal argument, he remarks, "leaves much out of account." His own argument turns largely upon the human capacity to learn how to control, even to suppress, strong and problematic affects and, over time, for entire populations to abandon specific disgust responses.
==See also== * Affective neuroscience * Amygdala * Aversion Therapy * Cognitive neuroscience * Contempt * Disgusted of Tunbridge Wells * Fear * Foodborne illness * Menippean satire * Nausea * Papez Circuit * Phobia * Social neuroscience * Taboo *Vomiting
==Bibliography== *Cohen, William A. and Ryan Johnson, eds. Filth: Dirt, Disgust, and Modern Life. University of Minnesota Press, 2005. *Douglas, Mary. Purity and Danger: An Analysis of Concepts of Pollution and Taboo. Praeger, 1966. *Kelly, Daniel. Yuck! The Nature and Moral Significance of Disgust. MIT Press, 2011. * Korsmeyer, Carolyn (2011) [https://books.google.com/books?id=NwsUasv4wmgC&printsec=frontcover&dq=%22Savoring+Disgust:+The+Foul+and+the+Fair+in+Aesthetics%22&hl=en&sa=X&ei=6AUGVYG8Ms3_8QXZ54EY&ved=0CBwQ6AEwAA#v=onepage&q=%22Savoring%20Disgust%3A%20The%20Foul%20and%20the%20Fair%20in%20Aesthetics%22&f=false Savoring Disgust: The Foul and the Fair in Aesthetics] Oxford University Press. . *McCorkle Jr., William W. Ritualizing the Disposal of the Deceased: From Corpse to Concept. Peter Lang, 2010. *McGinn, Colin. The Meaning of Disgust. Oxford University Press, 2011. *Menninghaus, Winfried. Disgust: Theory and History of a Strong Sensation. Tr. Howard Eiland and Joel Golb. SUNY Press, 2003 *Miller, William Ian. The Anatomy of Disgust. Harvard University Press, 1997. *Nussbaum, Martha C. Upheavals of Thought: The Intelligence of Emotions. Cambridge University Press, 2001. *Nussbaum, Martha C. Hiding from Humanity: Disgust, Shame, and the Law. Princeton University Press, 2004. *Nussbaum, Martha C. From Disgust to Humanity: Sexual Orientation and Constitutional Law. Oxford University Press, 2010. *Rindisbacher, Hans J. A Cultural History of Disgust. KulturPoetik. 5: 1. 2005. pp. 119–127. * *Wilson, Robert Rawdon. The Hydra’s Tale: Imagining Disgust. University of Alberta Press, 2002.
* [https://web.archive.org/web/20080513093810/http://www14.vjc.edu/academics/faculty/sherman_nancy/ Nancy Sherman, a researcher investigating disgust] * [https://web.archive.org/web/20070524043035/http://people.virginia.edu/~jdh6n/disgustscale.html Jon Haidt's page about the Disgust Scale] * [https://web.archive.org/web/20071103022419/http://people.virginia.edu/~jdh6n/moraljudgment.html Moral Judgment and the Social Intuitionist Model], publications by Jonathan Haidt on disgust and its relationship with moral ideas * [http://pup.princeton.edu/chapters/i7697.html Hiding from Humanity: Disgust, Shame, and the Law] * [http://www.birchmore.org/index.html Shame and Group Psychotherapy] * [http://www.nature.com/cgi-taf/DynaPage.taf?file=/nbt/journal/v22/n3/full/nbt0304-269.html "Is repugnance wise? Visceral responses to biotechnology" Nature Biotechnology] * [https://web.archive.org/web/20060217145556/http://www.classics.ox.ac.uk/faculty/princeton/KirkpatrickPurity0310.rtf Purity and Pollution] by Jonathan Kirkpatrick (RTF) * [https://web.archive.org/web/20080509062022/http://kuznets.fas.harvard.edu/~aroth/papers/Repugnance.pdf Paper on the economic effects of Repugnance] * [https://web.archive.org/web/20080513031630/http://www.channel4.com/culture/microsites/A/anatomy_disgust/science.html Anatomy of Disgust], Channel 4 program * [https://archive.is/20130416064459/http://whyfiles.org/shorties/278disgust/ WhyFiles.org] Article written about a February 2009 study in "Science" linking moral judgments with facial expressions that indicate sensory disgust. * [https://ejournals.library.ualberta.ca/index.php/crcl/article/view/10712 Disgust: A Menippean Interview]
Category:Emotions Category:Concepts in aesthetics Category:Morality