Prompted yet again by weekend newspaper reading, I found myself researching what disgust is. I discover it is a thoroughly investigated topic. Or, rather, it isn’t, because while there has been a lot of research done on it, it remains kind of elusive.
Here’s an academic medical explanation taken from a book review: from here and here:
Disgust is characterised by a remarkably diverse set of stimulus triggers, ranging from extremely concrete (bad tastes and disease vectors) to extremely abstract (moral transgressions and those who commit them). This diversity may reflect an expansion of the role of disgust over evolutionary time, from an origin in defending the body against toxicity and disease, through defence against other threats to biological fitness (e.g., incest), to involvement in the selection of suitable interaction partners, by motivating the rejection of individuals who violate social and moral norms. The anterior insula, and to a lesser extent the basal ganglia, are implicated in toxicity- and disease-related forms of disgust, although we argue that insular activation is not exclusive to disgust. It remains unclear whether moral disgust is associated with insular activity. Disgust offers cognitive neuroscientists a unique opportunity to study how an evolutionarily ancient response rooted in the chemical senses has expanded into a uniquely human social cognitive domain; many interesting research avenues remain to be explored.
Research on emotion (see) and its papers tells us that disgust is the most researched emotion (surprised?), followed by sadness. [Is that appropriate, that disgust is followed by sadness? Short stories please.]
Having read a good deal of this stuff, I am persuaded that there are several sources of disgust. Some of these, what we might call the oldest ones, are biological pathogen avoidance, perhaps seen when a baby rejects food. That does not mean that all food rejection is done so in disgust, but it may mean that some rejection we do is based on a deep-seated safety mechanism.
It is equally clear that some disgust is learned and that it can be unlearned.
Unlearned disgust
Taking the latter case first, there is a widely accepted (meaning I recognise it but found no good evidence) rejection of dead animal (including human). This could be because it is a source of disease. But medics learn to reject the emotional response in favour of knowledge. I assume that morticians do something similar, and that butchers draw a line to do with how long ago the death was.
Learned disgust
There is a general revulsion in Britain to flies on meat and flies on poo. This, I discovered to my surprise, is a learned social response based largely upon a campaign starting in 1911 to reduce all sorts of illness. Read this, especially the first few paragraphs. So presumably you and I learned this response from our parents in following example. You may feel that the prevalence of flies is now so low it is becoming unlearned – and that therefore we are ripe for a new onslaught of revolting pictures. Possibly.
There was a second campaign after the second world war – to do with washing after using the toilet – and later in the same article is a report on research into persuading people to wash their hands after toilet use. This latter campaign seems to have been less effective and much of the article chases the idea that disgust is such a powerful emotion it could be harnessed to change behaviour.
Why should we wash our hands? Because food poisoning accounts for the odd bi££ion or so of loss production just in Britain and it is assumed that most of the food poisoning comes directly from faecal matter in food, transferred from hands and stopped by sufficient washing. In 2007, researchers in Sydney placed some graphic posters in two washrooms, depicting a long bread roll filled with faeces. These revolting images were placed above the sinks and in the cubicles. Over a six-week period, the washrooms decorated with excrement sandwiches got through more soap and paper towels than a couple of control washrooms featuring posters showing clean hands and a bland informative message about disease prevention. So harnessing disgust to power change. A dangerous choice that could easily backfire.
I thought immediately of the disgust we have for the idea of insects on food and contrasted that with the food to be had from eating insects. I find it easy to believe that a fast-food burger in fifty years could be made from protein coming from insects rather than the meat of herbivores. I’m not so keen on crunchy insect (yes, I’ve tried it) and not at all on eating stuff that is still wriggling. I experience disgust and / or revulsion at moving food and I’m not at all sure I could change that. After all, I feel that way, slightly, about chewing my nails and I’m unable to stop that habit, one which you quite likely view with disgust.
Let’s go back to my first explanation: Disgust is characterised by a remarkably diverse set of stimulus triggers, ranging from extremely concrete (bad tastes and disease vectors) to extremely abstract (moral transgressions and those who commit them). I generally categorise the concrete cases as visceral, protection-mechanism stimulus which might be learned and mostly can be unlearned and the second, abstract set as more learned from societal preferences, choices and attitudes.
For example, while I am aware that some find same-gender sex abhorrent, I was aware even as a kid growing up in NE England that this was a learned response and my reaction was always to want to ask “Why do you feel that way?”, quietly wondering if this was as much a fear of discovery that one might be different, therefore non-conformist and a threat to a very insular society (quite possibly as much from being teenagers as from being where we were). I don’t want to do it, but it doesn’t disgust me – more than that, I don’t see why it should. Such behaviour is no threat to my health, it has a long history, it seems no less stable than different-gender relationships. I find it far less intrusive that a work colleague be of a same-sex preference than their being a vegetarian. ²
Many people find certain smells disgusting and therefore repellent. Curiosity is a counter to repulsion so I find it easy to over-rule many types of disgust reaction so as to investigate what it is that causes the reaction. It helps that my nasal functions are at least partly dysfunctional (I may smell, but I don’t detect smell well). I can extend this to many other situations.
I found evidence (via Rozin) that one type of disgust serves to help us avoid pathogens, typically avoidance of contaminated food. I did not find evidence (nor reporting of evidence) of biological evolution of disgust. Quoting: evidence for its origin in biological evolution, while quite plausible, has not yet been demonstrated. Disgust is not present at birth, it is not present in any non-humans if we include the focus on spoilage and contamination, and research has not mapped a path from genes to disgust. Although individual differences in disgust are in part heritable, we do not know that the basic circuitry for disgust is itself inherited.
Rozin, quite an expert on the subject, casts quite a deal of doubt on disgust as an evolutionary product (i.e., case not proven). The case for toxin avoidance (e.g., it is bitter, I won’t eat it) is clearly biologically evolved. Mapping that directly to disgust is a leap, and I agree (like you care). Picking carefully what he agrees with and doesn’t, the bitter-adaption face we make is transferred to become our standard ‘expression of disgust’.
I found a paper explaining the 3DD model, which separates disgust into three fields, pathogen, sexual and moral. I find I can’t resist using these as headings. Re-reading this in 2019, I wonder if you can catch yourself in a moue of mild disgust just reading these paragraphs. If you find one more so than the others, have you learned something about yourself? The educator in me wants to know if you think that useful or valuable. I say it this learning has just (or is about to) occurred and you might choose to ignore it or to embrace it. Not the disgust, the recognition of that.
pathogen disgust
This I find easiest to understand as possibly evolution, perhaps more exactly from evolutionary history. This is a reaction that helps us avoid pathogens – things that are bad for us, mostly food:
Pathogen disgust is elicited by objects likely to contain infectious agents, including dead bodies, rotting foods, and bodily fluids such as feces, phlegm, vomit, blood, and semen, and it motivates proximal avoidance of such things. Pathogen disgust is also elicited by stimuli emitting the same visual, olfactory, tactile, or auditory cues that reliably indicated pathogen presence in our ancestral past, even when an item possessing such cues may be devoid of infectious agents (e.g., plastic imitation vomit or fudge shaped to look like feces; Rozin et al., 1986).
Paraphrasing and plagiarising, it is evident that the things that elicit disgust capture a variety of sources of disease-causing agents. For instance, foods, animals, and body products are all potentially infectious. Similarly, three of the four elicitors of animal reminder disgust (dead bodies, individuals with poor hygiene, and body envelope violations) are also sources of contagion – even objectively noninfectious objects conceptualised within the animal reminder domain (e.g., amputated limbs, congenital deformities) elicit a disease-avoidance response. What were originally viewed as independent categories of disgust elicitors are more parsimoniously explained as related disgust elicitors within a broader domain of pathogen disgust.
sexual disgust
Sex addresses a separate adaptive problem: avoiding sexual partners and behaviours imposing net reproductive costs. There are some weaknesses with this as a sub-heading: for example, sex is a reminder of humans as animals, an identified source of disgust. Some of the measures of sexual disgust ask participants to note true or false to items involving moral judgments: “I think homosexual activities are immoral” and “I think it is immoral for people to seek sexual pleasure from animals.” The strength of the relation between moral judgment of homosexuality and bestiality and disgust toward those acts has not been established, leaving it uncertain whether these items measure a disgust response.
Picking out phrases and trying to join them together in a meaningful way (otherwise, plagiarising),
Disgust has been identified as
• a reaction to unwanted sexual contact,
• the antithesis of sexual arousal and
• the prototypical response when individuals are asked to imagine sex with close genetic relatives
• sexual acts are a specific category of disgust elicitors
• [suggestion that] sexual disgust is an evolved solution to the adaptive problem of avoiding biologically costly mates and sexual behaviours. Quite a bit cut out here, because I thought this sufficient and largely obvious.
In sum, avoiding sexual partners and behaviours potentially jeopardising one’s reproductive success constitutes a separate adaptive problem from pathogen avoidance and requires different systems for assessing the risks associated with sex. Sexual disgust, we argue, is specifically well suited to perform the function of avoiding reproductively costly sexual behaviours, narrowing the pool of sexual behaviours and partners to those likely to contribute to the production of healthy viable offspring.
I reckon that the general need for fewer humans on the planet makes this version of disgust a target for unlearning. I approve.
moral disgust
When asked to generate a list of things that disgust them, people often report antisocial behaviours alongside items and acts that we would categorise as elicitors of pathogen or sexual disgust. These social transgressions broadly include non-normative, often antisocial activities such as lying, cheating, and stealing that harm others directly and/or impose diffuse costs on one’s social group.
... When asked to generate a list of disgust elicitors, a Hebrew-speaking woman from Israel cited politicians, a Japanese-speaking student from Hiroshima cited verbal abuse, and an English-speaking student from Chicago cited child abuse.
You might think, as I did, that some of this reported disgust is different from other disgust, reporting disgust but not feeling it. Here’s a refutation that probably gave someone in the paper list (Moll et al, 2005) a PhD:
This hypothesis can be tested by examining whether pathogen-related acts and common socio-moral violations such as lying, cheating, and stealing activate common neural regions associated with the emotion disgust. Recent functional magnetic resonance imaging (fMRI) investigations show they do. ⁵
Wow. is that sufficient evidence for you?
____________________
Having now read all of the e-text of what is referenced below it seems clear to me that we have a range of disgusts which we learn – and we can show that this is so by comparing what it is that people find disgusting and that peoples find disgusting. Eating the eyes of sheep, eating locusts, being obese (a source of wonder or even envy to a traditional Fijian, of disgust or embarrassment to a fitness freak). Thus we should accept that some of the things that disgust us, in whatever groupings you care to consider, are learned as a society. If they are learned then other things can be learned as disgusting and some things can be unlearned, or have that learning modified, perhaps adjusted.
There is an entirely different problem with moral disgust. That is (source), demonstration of moral violations generates something more like disgust than anger. Investigators in this field have a range of things they present for reaction (see above and at link the 3DD, ³ three domains of disgust, scale), which (while interesting) don’t well explore whatever it is that elicits moral disgust. [You can imagine how the investigations go: for minimum wage you go sit in a chair to be shown a range of disgusting things, things others have or have not found disgusting. By various ways, your reactions are measured and compared with others. Exercise: write some job titles that, for you, fit this description].
We do not yet understand how our culture produces such reactions but we can see it covers areas of religion, politics and morals. It covers attitudes to fairness, but research in this is soon confusing anger with disgust. It is clear that what disgusts you may well not disgust me (and vice versa) but we are likely to agree more if we have background in common, where what has been investigated most is common culture. Whatever that means; for all I know we will soon have part of the Britishness test including stuff that you are supposed to learn is disgusting.
For example, how do you feel about people who cheat to pass exams or cheat to get good grades or cheat to gain qualifications for which they are unfit? Is that reaction anger or disgust? Does your reaction depend upon or vary with how directly threatened you feel by such an event? In some sub-cultures the reaction is admiration, even envy.
Obscenity is loosely defined ⁶ in the sense that it is difficult to draw a line between two items, one obscene and the other not. I’m not at all sure if pornography is the same as obscenity. Might we agree what pornography or pictographic obscenity is sufficient to be labelled as eliciting disgust? I suggest that while we might agree in some respects, the range of things accorded ‘disgust’ is surprisingly varied. I don’t say that because I know how weird my tastes are, but based on the difficulty of drawing any line – the boundary is bound to be wide and grey.
Are you aware, when expressing disgust on occasion, that you are in a minority at the moment? If I see such a thing, I am fascinated at the existence of difference and immediately wondering how such different reactions to an event might have come about.
Disgust is such a strong reaction (compared, for example to like and dislike) that it deserves research both in the sense of the psychology and what that tells us about our societies. Further, having learned how disgust can be used to shape our culture I merely wait to see what it is that those in the advertising (a.k.a. thought control) business attempt when using this to cause us to do what they want.
Or what They want.
DJS 20160805
Buy buy or bye bye?
Pic at top from Wikipedia as ever, this at https://thescrutor.files.wordpress.com/2013/10/copy-of-expression-explanation-v2-compatibility-mode3_0001.png
Seeing recent examples of hysteria on social media (possibly a later essay) I wonder whether we, in being in general very poor at analysis of information from such sources, are ripe for some extreme events. Future school-equivalents, I predict, will revert to analysis, along with, I hope, measurement of the trust we can or should put into statements from obviously biased sources.
Edit 20190205:
Reading that pair of sentences in 2019, my reaction is "Bloody hell, that was right". Brexit, Trump are stand-outs, but you could probably write a list of ten without needing research. Go on, exercise.
If you got this far, you might now enjoy an article I found in the Atlantic this week (that was the link). This, among other points, measures the robustness of a connection between what you find disgusting and your political leanings, finding that it is consistent. “disgust influences our political views as much as or even more than long-recognised factors such as education and income bracket.” Now that is scary. Look at the point again from the viewpoint of someone like Cambridge Analytica (who, since they have vanished, are now safe to point a finger at in a characterising way) who thinks they can target your political opinion and change it.A second point worth copying here is the connection between reaction to immigration and sensitivity to infection. Crunching the numbers (the results are as yet unpublished), the researchers found that resistance to immigration is greatest in states with the highest incidence of infectious disease and where worry about this, as reflected by internet activity, has also been high. So this tells you which political leaning feels disgust more easily, doesn't it? Again, this correlation rises over the other likely effects of things like income and education; again, a pretty scary discovery.
We can go further; having (more or less) established a connection between disgust sensitivity and conservative moral values, we might look where else that extends. How about religion? I contend immediately that this is the other way about; a religion teaches what it is will elicit disgust – and I leave it to you to agree or disagree.
That disgust indicates how you fell politically is instructive and worrying. We have learned recently the levels at which our opinions can be shaped (distorted, adjusted) and we are, for the most part, unaware how that occurs, even if we are aware that it has occurred. Some of the later ideas in the Atlantic piece indicate that how well your taste receptors function is undeniably genetic, but that this means someone who has more sensitive tastebuds will be sensitive to bitterness, so more easily tastes bitterness, which leads directly to disgust – and therefore conservative politically. Turn that around; if you like bitter salad ingredients, you're twice as likely to be liberal in your political views. Not all, just twice as likely. Of course that doesn't mean you vote that way, but it does affect your leaning. It may go a little way to explaining political trends measured against increasing age, though I'd say I have grown to prefer the bitter-tasting food as I've grown older, while I'm aware that I'm also supposed to become more conservative. That doesn't fit, does it? But then the correlation is proven, but it is not strong. In social science anything repeatable is wonderful and being able to measure something with any confidence is something of a holy grail. Disgust is studied so thoroughly because it produces results that stand scrutiny.
In terms of political manipulation, though, disgust is a mild emotion by comparison with, say, anger. So it might be considered something of a hack by those wanting to manipulate us, since many of us simply wouldn't notice. Perhaps we should.
I'm going back to university to study disgustology.
Kidding; this was fun enough.
DJS
These links will take you to several longer reads on the topic. I picked out from these what I wanted to explore.
http://www.salon.com/2011/07/24/disgust_interview/ the commentary afterwards includes some wicked ‘disgusting’ jokes. 10
http://www.barnesandnoble.com/w/yuck-daniel-kelly/1111658256;jsessionid=D1098FA49A3B1B68A005BAC796678BB2.prodny_store01-atgap09?ean=9780262015585 points to book with same lead picture as URL above
https://www.amazon.com/Disgust-Humanity-Orientation-Constitutional-Inalienable/dp/0195305310 again, a book reference.
http://www.read4freebooks.com/recommendations-book/side-splitters On usenet, too.
http://www.ncbi.nlm.nih.gov/pubmed/22256964
http://emotionresearcher.com/editors-column-understanding-disgust-issue/ A longish read.
https://www.theguardian.com/society/2016/jul/26/disgust-science-public-health-hygiene
http://emotionresearcher.com/on-the-origin-of-disgust/ Paul Rozin, Penn U. Good references, of course.
http://emotionresearcher.com/on-the-expansion-of-disgust/
http://emotionresearcher.com/evaluating-distinct-evolutionary-theories-of-disgust/
http://www.ncbi.nlm.nih.gov/pubmed/22218974
https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwj22P_BtarOAhVXFMAKHWeMAvAQFggeMAA&url=https%3A%2F%2Fcarlsonschool.umn.edu%2Ffile%2F49186%2Fdownload%3Ftoken%3DU1LfiGmS&usg=AFQjCNG2zbztFX2kAmWALyhFGF9Hv5HO4Q&sig2=A26kSRt8sCFOqWivA_Tg8g&cad=rjt direct link to a pdf paper by Tybur, Lieberman and Griskevicius, 2009
Footnote numbering is currently even less ordered than previous attempts.
1 not found.
2 I’ve written about this before: experience says that sharing a table with a vegetarian demands they they preach their attitudes and values. I find this prating worse than a political or a religious opinion because I can stem those more easily. If that is the way you feel, fine. If you dislike my behaviour, also fine. You chose to sit with me to eat and, given such behaviour, I will in future attempt to not sit with you. My diet preferences include meat; I have raised meat for eating; while I have not eaten my own meat, I have sent meat to market. I have (twice, I think) prepared meat for eating starting from the carcass. I have not killed for meat but I have observed this process close up. I am relatively comfortable with the whole process. I see eating meat as perhaps wasteful of planetary resource, but to me the problem is human overpopulation driving down the usefulness of animal protein, not an inherent lack of need for such foodstuff. It is a matter of choice and while I still have it, I will exercise it.
3 disgust models 3DD and RHM ⁴ Quote from the abstract of 3DD : This investigation examined the measurement properties of the Three Domains of Disgust Scale (TDDS). Principal components analysis in Study 1 (n = 206) revealed three factors of Pathogen, Sexual, and Moral Disgust that demonstrated excellent reliability, including test-retest over 12 weeks. Confirmatory factor analyses in Study 2 (n = 406) supported the three factors. Supportive evidence for the validity of the Pathogen and Sexual Disgust sub-scales was found in Study 1 and Study 2 with strong associations with disgust/contamination and weak associations with negative affect. However, the validity of the Moral Disgust sub-scale was limited. Study 3 (n = 200) showed that the TDDS sub-scales differentially related to personality traits. Study 4 (n = 47) provided evidence for the validity of the TDDS sub-scales in relation to multiple indices of disgust/contamination aversion in a select sample. Study 5 (n = 70) further highlighted limitations of the Moral Disgust sub-scale given the lack of a theoretically consistent association with moral attitudes. Lastly, Study 6 (n = 178) showed that responses on the Moral Disgust scale were more intense when anger was the response option compared with when disgust was the response option. The implications of these findings for the assessment of disgust are discussed.
so much for blind copy and paste. Unhelpful, I feel. Putting disgust and discussed in the same line is a move I first played with in 1976.
4 RHM disgust model. RHM posit four functions for disgust: 1) to neutralise pathogens; 2) to neutralise the purported threats posed by reminders that humans are animals; 3) to maintain social distinctiveness, and 4) to protect the social order. From here, but you might want a longer review. Prototypical animal reminders [2], under this framework, include dead bodies, deformity (e.g., burn wounds, port wine birthmarks), bad hygiene (e.g., body odour), and sex. RHM also posit domains of “interpersonal” disgust, which they argue functions to maintain social distinctiveness [3], and moral disgust [4], which they argue functions to protect the social order.
5 For instance, conjunction analyses revealed that pathogen-related acts, incestuous acts, and socio-moral violations all activate a network of brain regions previously reported to be associated with disgust (e.g., the globis pallidus, putamen, caudate head, and amygdala). Behavioural studies also indicate disgust is linked with moral judgments further suggesting that disgust is not just used metaphorically or rhetorically to describe social transgressions, but instead reflects a response toward multiple elicitors including infection, incest, and iniquity.
From an evolutionary perspective, avoiding interactions with other individuals who imposed costs on oneself or on members of one’s social network would have been beneficial. Within the social arena, other individuals are capable of inflicting costs in a number of ways; in addition to lying, cheating, and stealing, group members can injure, kill, rape, free ride, denigrate, and cuckold. Such behaviours inflict costs directly, and they can disrupt cooperative relationships, social networks, and group cohesion. Individuals capable of avoiding those whose actions regularly registered as large net costs would have fared better than those who did not discriminate along this dimension. In addition to being elicited by different cues than pathogen and sexual disgust, moral disgust motivates a different behavioural strategy. Whereas pathogen disgust motivates proximal avoidance of perceived infection risks and sexual disgust motivates avoidance of individuals within the specific context of sexual interactions, moral disgust motivates avoidance of social relationships with norm-violating individuals. As recent research indicates, moral disgust might also underlie motivations to punish norm-violating third parties.
6 I found the below earlier in the week, looking at entirely different things (claims of ‘liar’ are rejected by me). Quoting wikipedia
In explaining why the material at issue in the case was not obscene under the Roth test, and therefore was protected speech that could not be censored, Stewart wrote:
“I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description ["hard-core pornography"], and perhaps I could never succeed in intelligibly doing so. But I know it when I see it, and the motion picture involved in this case is not that.”[4]
The expression became one of the most famous phrases in the entire history of the Supreme Court.[5] Though "I know it when I see it" is widely cited as Stewart's test for "obscenity", he never used the word "obscenity" himself in his short concurrence. He only stated that he knows what fits the "shorthand description" of "hard-core pornography" when he sees it.
10 Of which my favourite, simply ‘cos it forced me to think, reread and repeat, was, left in US English:
What's the difference between a rooster and a trial lawyer?
A rooster clucks defiance. and a lawyer fucks the clients
