Sci used to be a vegetarian. I decided on being a vegetarian the summer after high school, on a trip across the United States, while studying environmental and land use issues. I guess it’s not too surprising that some of the things I found led me to give up meat. And give it up I did, for several years. Unfortunately, I was a really bad vegetarian. Not in terms of eating meat, I was very good at not eating meat. What I was BAD at was eating everything else. Without meat my diet basically extended to bread, cheese, and…other ingredients common to cheese pizza and pasta covered in…cheese. When I started to suffer issues associated with malnutrition (especially anemia), my doctor and family demanded a more balanced diet. Now the Sci-house eats poultry roughly twice a week (except Scicat, obligate carnivores gotta eat). But I have also become a MUCH better eater in general. I now eat piles of dark leafy greens, fruit, and vegetables. Whole grains abound.

But I noticed something during my years as a vegetarian. Meat just didn’t interest me. Most of the time, it still doesn’t. I tend to look for, and cook, vegetarian recipes because they just appeal to me more. But for many moral vegetarians (people who become vegetarians because of moral reasons), it goes beyond indifference to meat, and all the way to disgust. Meat has become something disgusting, something that is the result of processes that they find distasteful and wrong.

And some scientists wondered…is it just meat? Or are people who are vegetarians for moral reasons more likely to feel disgust in general?


(Obligatory photo of our adorable obligate carnivore. Could anyone refuse that face?!)

Fessler et al. “Disgust sensitivity and meat consumption: a test of an emotivist account of moral vegetarianism” Appetite, 2003.

The idea that the authors of this paper are testing is one of “emotivist” reasoning. This basically suggests that your reasoning arises because of previous emotional processes…in other words that you rationalize after your gut’s already told you something. In this view, you would become a moral vegetarian because, at heart, you are more likely to find meat disgusting, and you rationalize it after the fact. This is only one view of moral reasoning, but it is the one that this paper was looking at specifically.

There is some data that supports this view. For example, moral vegetarians find meat more disgusting than people who are vegetarians for health reasons. There are theories that if you have a moral injunction against eating meat, you create a link to strong emotions that promote disgust (say, images of slaughterhouses). And many moral vegetarians become vegetarian because they have been exposed to powerful emotional experiences, which would mean that the disgust preceded the conscious decision to become a vegetarian. The question then is whether moral vegetarians are just more likely to be disgusted in general, and then to make decisions like vegetarianism based on that.

I’m not so sure about this concept. Yes, the disgust would precede the decision to become a moral vegetarian, but this does not mean that you were ALWAYS more disgusted by mean. Probably you weren’t before the powerful emotional experience.

Another bit of circumstantial support is that women are more likely to become vegetarians than men. Women also display more disgust toward meat and toward things in general than men do. That’s a correlation, sure, but it’s not causation.

Finally, disgust does tend to carry over. People who show a lot of disgust in one domain (say, guts spilling out everywhere a la the end of Braveheart), also show more disgust in other similar domains, like seeing someone stick a fishhook through their finger. So the hypothesis here is that moral vegetarians will show more disgust in response to meat, and that this will carry over into other similar domains like blood and guts, showing that moral vegetarians show more sensitive disgust responses overall.

So the authors here conducted a web survey looking at measures of disgust, and comparing it with the amount of meat eaten on a regular basis. They got 1340 responses to a web survey, in which they asked about how often you ate meat, how often told others not to, and took measures of disgust by asking for responses to pictures of things like roaches, bodily fluids, combinations of mayonnaise with something that DOES NOT go with mayo (like…ice cream?), etc (I’ll just let you picture those for yourself, but you can look at the test here). In order to make sure that people did not guess the point of the study, they conducted the survey to look more like a nutritional survey than one looking at moral responses.

What did they find? Women tended to consume less meat than men (this was carried by red meat consumption). Women were also more disgust sensitive, which replicates previous studies. Disgust measures in general declined with age (at some point, you’ve seen it all).

When they separated out people who didn’t eat meat exclusively due to moral concerns, they were left with only 80 people (I’m rather interested that they didn’t get more than that with such a large sample). But did this sample show more disgust sensitivity?

Nope. There was no correlation between moral vegetarianism and disgust sensitivity. In fact, there was a small positive correlation between white meat consumption and disgust sensitivity. But moral vegetarians had no increase in disgust sensitivity compared to the general population.

While this study has some interesting findings, I’m not really sure it got at the question it was meaning to answer. The online survey didn’t have people DECLARE themselves vegetarian or not, instead it qualified people who didn’t eat any three of the meats listed, and then asked why, and made you pick moral or health. This is probably why they had such a small moral vegetarian population (most vegetarians have more than one reasons). I realize that they did a lot of this to make sure that people didn’t understand the point of the study, but I don’t think it really made for clear findings. In fact, I’m not sure a web survey is at all the best way to approach this. If it were my study, I’d deliberately recruit omnivores, vegetarians, and vegans (with maybe a screen on environmentalism related issues). I’d have them come in and take a survey on disgust, not on their eating habits at all. I might also take physical measures of disgust while they were exposed to disgusting things (for example, the faces associated with disgust are universal, or you could look at fMRI measures of the insula). I think you might then get a clearer picture of whether or not people who are vegetarians or vegans are more easily disgusted in general. I also don’t know that distinguishing by moral or health is generally the best principle. Dieters, for example, can show higher disgust responses, and this might extend to health related vegetarianism.

However, I also think that the general finding here, that moral vegetarians are not more easily disgusted by…stuff…is probably the right one. Disgust at one TYPE of thing does not necessarily carry over to another, particularly when disgust for the original item is something that is morally derived and not something that the vast majority of humans are disgusted by (say, meat as compared to feces or vomit). The idea that it would carry over to blood and guts is a good one, though. I wonder if the authors would have seen an effect if they’d deliberately selected out the blood and guts domain of the disgust scale, and I wonder why they didn’t.

But appears that this study does not support feelings of general disgust underlying moral vegetarianism. Instead, the authors hypothesize that disgust is a consequence of your moral decision making. Mind over gut, at least when it comes to meat.

Fessler DM, Arguello AP, Mekdara JM, & Macias R (2003). Disgust sensitivity and meat consumption: a test of an emotivist account of moral vegetarianism. Appetite, 41 (1), 31-41 PMID: 12880619