What Is Disgust?
Disgust is an emotion and a corresponding aversive reaction that serves to protect us from disease and contamination. A clear indication of this is that we are the most disgusted by things and situations that may lead to contamination – infected wounds, feces, blood, rotten food (or rotten anything), people with bad hygiene, mice, fleas or other animals know to spread disease.
Since disgust has such an obvious function and is found in every known culture, as well as being expressed in exactly the same way in around the world, we have every reason to believe that it is an evolutionary trait. And as psychologist Jonathan Haidt and many before him have pointed out, disgust has likely evolved from a simple reaction to pathogens into a foundation for moral judgments – the filthy person isn’t just somebody who needs a shower. This wider range of disgust is shown in the additional dimensions of sexual and moral disgust in which the reaction isn’t primarily a protection against contamination but against other dangers having to do with survival and reproduction.
Correlates to Personality
In other words, disgust seems to be a wide personality trait, and like any other such trait it shows a great deal of individual variation. Research has found disgust to be linked to Neuroticism with a correlation around 0.45, which makes sense since it is an emotional reaction. Other than that it shows pretty modest correlations of around 0.3 to HEXACO Honesty-Humility. So there is a case for viewing disgust sensitivity as a fundamental personality factor along with Haidt’s other moral foundations. Which I suspect would be a great substitute for the Big Five, but that’s another story.
Correlates to Social Attitudes.
Psychologists theorize that disgust should be directed at strangers more than familiar people. This would be due to the fact that humans have lived in small groups that were likely to share diseases, pathogens and immunities. But members of outgroups could easily introduce completely new pathogens that the group had no protection against. If this is true, then people who score high on disgust sensitivity should also have a more negative attitude towards various outgroups. Research has shown this to be true: people who are easily disgusted have more negative attitudes towards for instance foreigners, disabled people and homosexuals. Disgust sensitivity has also been linked to various measures of political and religious conservatism. One study by psychologist John Terrizzi and colleagues at the Virginia Commonwealth University showed correlations in the range of 0.33-0.49 whereas measures of conservatism unrelated to the idea of contamination, like minimum wage and health care, showed negligible correlations. At the same time, inducing disgust has also been shown to increase ingroup favouritism and outgroup hostility which suggests that a lot more than those who are easily disgusted can become hostile towards outgroups under circumstances that promote disgust, such as an epidemic. Studies have also found a seemingly curious effect in that liberals have less prejudice against foreigners and homosexuals when being primed with disgust before their judgments. But as X points out, this is most likely because they view these categories of people as part of their ingroup. So they essentially show the same pattern as conservatives. How they react to their own outgroups has yet to be examined.
The Effect of the Climate
If we take the example of a negative attitude towards homosexuals, hobby-psychiatrically referred to as homophobia, the most common theories on the origin of this attitude are about being gay and repressing it with anger or being scared of others thinking you’re gay and demonstratively objecting to it in order to divert suspicions. It’s very easy to see how these theories are problematic. If being gay would explain even half of the cases of homophobia it would mean that roughly half of the population in many countries in the Arab world must be gay. It would also mean that the number of gay people in for instance Eastern Europe must have increased dramatically for the change in attitude seen there in recent years to make sense. If it was about fear then why are there substantial minorities of homophobes in the most liberal countries like Canada or Holland, where no one gives a damn if you’re gay or not?
Clearly the case for disgust sensitivity appears much stronger. This could also provide an explanation for why some countries are more homophobic than others. If we look at maps of the prevalence of infectious diseases it seems clear that the most cases are found in Africa, the northern half of South America, the southern part of Central America, South- and South East Asia. In these countries there is a high population density that enables disease to spread more easily. It’s also warm, so vector organism can multiply more and aren’t forced to hibernate during winter. Here is a WHO map of combined infectious diseases,
Compare this to the PEW map of negative attitudes towards homosexuals,
Or, for that matter, the World Value Survey map of racism,
Sure, it’s no doubt more than one cause behind these attitudes. One likely candidate is clannishness/tribalism which is common in the Muslim world. This trait might explain some anomalies like the conspicuous French racism and the relative lack of homophobia in South America, although the difference between the northern and southern half of South America is striking nonetheless. Russia and Eastern Europe is also an anomaly but this can probably be explained at least in part by the collapse of the Soviet Union. During the communist era citizens were provided with free health care but after this system collapsed life expectancy rates have decreased sharply and infectious diseases like tuberculosis, HIV and even malaria have become more common. All in all, it seems pretty likely that some peoples who have originated in a warm climate would be more prone to outgroup hostility, or that the prevalence of infectious diseases could trigger such hostility.
So, Homophobia and Racism Is Ok Then?
Not exactly. Approving of behavior on the grounds that it’s human nature is absurd. Murder and rape is human nature too; it has been present in every known culture. Our attitude towards other people is always going to be at least partly about choice. If we want to fight these negative attitudes then knowledge is preferred to homespun theories. And knowledge, although still shaky, suggests that fighting racism and homophobia may be more about treating infectious diseases and stopping global warming then lecturing school children or having pride parades.
Of course, not all diseases are disgusting,