The Psychology (and Politics) of Disgust | Kathleen McAuliffe | Big Think

Similar parts of the brain - there's a lot of overlap in how we process both visceral disgust and moral disgust. Psychopaths - needless to say, they're these cold-blooded killers who are overrepresented in many of our high-security jails. These individuals show damage to many of the same circuits that are involved in disgust.

Another group of individuals, although they're not predatory, are people with Huntington's disease; it also damages some of the circuits that are involved in disgust. People with Huntington's disease tend not to be empathetic, and they think that this is related to these circuits being damaged. They're almost unique in that they experience almost no visceral disgust whatsoever.

So, somebody with Huntington's disease, for example, would think nothing of picking up feces with their bare hands. There is this sort of very interesting interrelationship, at least in the brain, between visceral and moral disgust. A little-known fact is that conservatives are more disgust sensitive.

There's a huge variation across populations in how disgust sensitive people are. There are actually standardized scales that measure, for example, the questionnaire you fill out, and it will ask you questions about how revolted you would be if you stepped on dog poop or if you saw a cockroach on pizza or a dirty toilet.

As a result of filling out these questionnaires, they've been able to look to see if there's parallels between how disgust sensitive someone is and how conservative they are. Indeed, there is a correlation. The reason for that is because, again, conservatives, if you really break down their belief systems, tend to have conservative sexual values.

For example, concepts like virginity pledges are ideas that they're fond of. They also tend to be more opposed to immigration, and foreigners are a leading source, at least in centuries past, of exotic germs for which we had no natural defenses. So, it's speculated that this could be another factor behind why people who are more conservative in their political ideology tend to be opposed to immigration.

Conservatives also tend to be very tradition-bound. They tend to be a little bit more rigid about following religious doctrine. Again, a lot of religious practices may help to protect against infection. That's the leading theory as to why you see this association.

In general, even in large survey studies, they've shown this link between germophobia and xenophobia. For example, there was a paper actually about to be published, and I think they looked at 2,000 Danes and 1,200 Americans, representative samples from both countries. They found that opposition to immigration increased in direct proportion to the disgust sensitivity of the individual.

Another group did a study of 25,000 Americans. The study was done at the time of the 2008 presidential election between John McCain, a more conservative candidate, of course, and Barack Obama. They found that the more disgust sensitive the person was, the more likely they would vote for John McCain.

They actually showed the proportion of votes that went to McCain in each state, based on the average disgust sensitivity of the state, derived from individual respondents to the survey.