I thought the generally accepted science was that humans can learn disgust reactions socially, so that they are more adaptable on a non-evolutionary timescale.

> The disgust system is a psychological mechanism for producing pathogen avoidant behaviour [10–12]. In previous work, we have stressed the universality of disgust, showing that there is much that is similar about disgust responses between animals and humans, between humans and over historical time [11,13]. However, there is also much that differs between individuals and between social groups. In this paper, we look at disgust and disease avoidance behaviour in human individuals and in human social groups as an adaptive system. Natural selection has produced a solution to the problem of hard-to-detect parasites by designing a system that is sensitive to local information about infection risk. This system responds to parasite pressure not just over evolutionary time, but over lifetimes, using what cues it can. This may be information about an individual's current state, its history of sickness and exposure to disgusting experiences, or what it has learnt from the local culture and from the hygiene practices of others.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3013466/

I know a bunch of people who have gone off specific foods after being coincidentally sick and associating the two things.

There's a strong cultural component when it comes to disgust. People in many parts of the world eat insects regularly as a part of their standard diets. In the US, most people don't think of honey or lobster (aquatic arthropod) or carmine (red food coloring) as "insect food" but these items most definitely fit in that category and are commonly consumed.

In the past, people in the west found yogurt, sushi, and lobsters absolutely disgusting. Now many will happily eat those foods, and even consider them delicacies.

Some disgust reactions are hard-wired (e.g. reactions to fecal matter or vomit), and others are culturally learned.

> Some disgust reactions are hard-wired (e.g. reactions to fecal matter or vomit), and others are culturally learned.

Curious if you've got a source for that, because I've lived with 3 infants and every one of them was delighted by the squishiness of poop and needed to be taught that disgust response.

Those same populations have much higher parasitic infections as well. That's the whole point of the study on which we are commenting.

The greyness of your comment possibly indicates it has been deemed bigoted. It's relevant regardless. The subject of human parasitology certainly shows geographic and cultural distributions. One example is a strange case of neurocysticercosis, perhaps the most common cause of epilepsy and result of taenia solium or pork tapeworm. The case I recall involved a Jewish family, all infected and symptomatic. Doctors had difficulty discovering the source due to both assumed rarity of the disease and the preclusion of pork in a kosher diet. The eureka was the servant, who did not practice a kosher diet. Because this worm can lay 80k eggs per day, all of which are small and sticky, they tend to accumulate under fingernails, presumably as a result of grooming and outlier of hygiene. There are numerous parasites that are either or both geographically and culturally concentrated. In the US, neurocysticercosis is most common in California. According to sources not my own, this is due to the larger population of individuals who come from areas where swine handling is more common, along with certain mitigation practices or lack thereof. The French have a higher rate of toxoplasmosis, possibly due to, eg steak tartare. There are many examples.

Look at a map of countries that eat insects. Compare it to a map of per capita parasitic infections.

The study above indicates that this is not just a correlation.

> Some disgust reactions are hard-wired (e.g. reactions to fecal matter or vomit), and others are culturally learned.

Others are learned by experience. I used to like peppermint a lot, until one day in uni I poisoned myself by drinking half a bottle of peppermint schnapps. Ever since then, for many years, the smell of peppermint makes me dry heave and physically gag uncontrollably. I cannot tolerate peppermint at all, something in my brain 'learned' that peppermint is a poison and won't tolerate it.

How does this invalidate the point?

The people who are using their brain to override their disgust system are probably doing something that's extremely maladaptive.

It literally says that what we evolved was a system that can learn that something is bad via society like eating dogs and horses vs eating pigs and cows. The pig eaters and the dog eaters aren't overriding anything, because they didn't learn it in the first place.

It invalidates it because you're saying disgust is evolutionary. The response is saying it's largely cultural, thus something that triggers disgust is not going against some "evolutionary truth" but is rather just another learned behavior.

If it's purely cultural and has no connection to reality then it should have "evolevd out" of us. But it hasn't. Being influenced by culture is part of how the system works. The reason you learn disgust is you can't afford to learn by trial and error so you outsource to society.

Now if you think you're a smart ass and decide to "override" the cultural "indoctrination" that makes you find insects disgusting, what do you think is the likelihood that you are the one who is right?

In all likelihood you will find out after some time that you made a huge irreversible mistake.

Social transmission is an evolved trait that is beneficial, and transmitted disgust that prevents disease spread is absolutely one reason it might be beneficial.

I didn't eat scrambled eggs for ten years or so after once choking on a forkful when I was around seven years old because I found them absolutely disgusting.