The Frontal Cortex

The Neuroscientific Case for Vegetarianism

Posted by Jonah Lehrer on April 26, 2007
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Christof Koch makes a compelling argument:

My empirical studies into the neurobiology of consciousness have convinced me that many species share the sights and sounds of life with us humans. Why? First, except for size, there are no large-scale, dramatic differences between the brains of most mammals (including humans). Second, when people experience pain and distress, they contour their face, moan, cry, squirm, and try to avoid anything that would trigger a reoccurrence of the pain. Many animals do the same. Likewise for the physiological signals that attend pain–like changes in blood pressure, dilated pupils, sweating, and an increased heart rate. Because it is likely that mammals can consciously experience the pains and pleasure of life, we should not be eating their flesh.

It was difficult for me to follow this growing realization with action–the taste of meat is deeply ingrained! The death of my beloved companion Nosy a few years ago provided the final impulse to make me live in accordance with my belief. I am now an ovo-lacto vegetarian.

Koch, of course, is right. One of the great themes of post-Darwinian science is the inter-relatedness of life. From the perspective of our cells, there is little difference between a human and a chicken, or even a sea slug. All animals use the same neurons and the same neurotransmitters. Pain receptors in different species share a similar design. Blood and flesh and skin are always constructed of the same elemental stuff.

That said, I really like the taste of bacon.

But I also wonder about the corollary of this argument. Let’s say there was a species that used a totally different design for its neurons, and reacted to pain in a completely unique way. In other words, this species didn’t share our biological inheritance. Would it then be alright to eat them? I mean, at a certain point vegetarianism just has to be about not consuming living things, regardless of whether not they share our nociperception or sensory system.

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Comments

  1. #1 Epistaxis
    April 26, 2007

    Would it then be alright to eat them? I mean, at a certain point vegetarianism just has to be about not consuming living things, regardless of whether not they share our nociperception or sensory system.

    No. Koch isn’t saying that we shouldn’t inflict pain on animals because they’re related to us; he’s saying we shouldn’t inflict pain on animals because they’re capable of experiencing pain. Our common ancestry is just a way to become aware of that fact. Granted, it might be harder to recognize pain in a completely unrelated species, but once we know it’s there, it’s the pain, not the relationship, that matters.

  2. #2 RyanG
    April 26, 2007

    I think you missed the point here. It’s about not eating things that can feel pain, rather than about not eating things that are related to us. If the latter, we wouldn’t be able to eat plants, either.

    Vegetarianism does not logically follow from the realization that animals can experience pain. And his earlier point, that brain structures are similar in all mammals, could only really be used to argue against eating other mammals.

  3. #3 Kurt
    April 26, 2007

    Douglas Hofstadter, in his new book “I am a strange loop”, also talks about this distinction and where he draws the line as far as what he’s willing to eat or kill.

    When Peter Singer was on The Colbert Report a while back they mentioned in passing the idea of growing muscle tissue in vitro — in that case it would be perfectly acceptable for vegetarians to eat meat (at least, of course, for those people who came to vegetarianism for the above reasons).

  4. #4 PasserBy
    April 26, 2007

    This is just the argument from empathy. Of course the animals we eat need to be murdered, and killing things typically hurts them, and it is right for us to empathize with them. To me, this is the one remaining justification for religion — it gives us a way to express thanks for the sacrifices that are necessary for our survival. Our lives today allow us to believe that meat comes from a plastic bag, but the profound truth is that some”body” died so we could live.

    Oh, and it makes no sense to limit the argument to animals, except for the social response they trigger: empathy.

    The other argument for vegetarianism is the argument from health. I’d still need to be convinced there.

    PB

  5. #5 ABR
    April 26, 2007

    “I mean, at a certain point vegetarianism just has to be about not consuming living things, regardless of whether not they share our nociperception or sensory system.”

    Plants are living things, as are, to some extent, the fruits and nuts they produce. If they have a nociceptive system, it would certainly be completely different from our own. It would be impossible to disprove that plants don’t experience pain since it’s such a subjective experience.

    The fact is that wherever you draw the line, you are drawing an arbitrary line. So, unless you figure out a way to live off of photosynthesis or eating rocks, you are going to have to get used to the idea of killing living things.

    Even if you limit your definition of living things to the animal kingdom, you have some tough decisions to make. Do you stop eating shrimp or oysters? Would you stop swatting flies? Would you let a tapeworm infection go untreated?

  6. #6 Jonah
    April 26, 2007

    Everybody’s right, of course. Plants are living things too. I made a mistake. I meant to say “living creatures”. My own personal answer to ABR’s provocative questions revolves largely around the ethics of the farm where the animals were raised, and not the neuroanatomy of the species on my plate. I’m pretty strict about avoiding mass produced chicken meat and eggs. I buy organic milk and bacon and rarely eat beef. I stick to sustainable fish. Obviously, these are aspirations – I’ve been known to enjoy the occasional fast-food burger – but they are how I live with not being a real vegetarian.

  7. #7 Carolina
    April 26, 2007

    Animals kill each other for food too. Should we stop the wolf from killing a rabbit? The wolf is going to die from malnutrition, the number of rabbits might increase until it becomes an ecological concern… My cat lived to hunt birds and killed many of them. That’s just the way the food chain works.

    But modern farming practices are painful for animals. We ought to let the chickens run free, the calves be with their mothers in the field etc.

  8. #8 Whatever
    April 26, 2007

    Luckily for all living creatures, once you “shuffle off this mortal coil” you won’t remember the pain you experienced while you were alive. I don’t want to be the food for another creature, but if it so happened I wouldn’t care afterwards.

  9. #9 Daniel
    April 26, 2007

    I have seen guerillas on TV in their natual habitat in Africa. They are very human-like, except that they are much more physically robust, and massivley built. But all they eat are vegetarian leaves. Could we live like that I have wondered? I don’t think so, because we have a much more complex brain, that apparently requires more complex proteins to grow and sustain. The nature of our teeth suggest a meager carnivourous leaning. And human digestion works best with lots of vegetable matter. So, maybe we are intened to eat a little meat, but not very much. I am not sure what I mean by “intended;” I mean a little meat in our diet would probably be optimal. Consuming as much meat as we do in Western countries, at least, is probably not very good for people or animals.

  10. #10 Ted
    May 3, 2007

    Hmm … perhaps we should just breed cows that are masochists. Then we can eat them – they’re happy, we’re happy, everyone wins. ;-)

  11. #11 Gill Bates
    May 4, 2007

    Koch, of course, is right. One of the great themes of post-Darwinian science is the inter-relatedness of life. From the perspective of our cells, there is little difference between a fully grown adult human and a comatose person or even a newborn infant. All people use the same neurons and the same neurotransmitters….

    That said, I really like the taste of newborn human babies and comatose ‘vegetables.’

  12. #12 Daniel
    May 4, 2007

    People nowadays are getting fatter and fatter. People confide in me about their problems fighting the fat. So, I have been doing alot of thinking about it; why are people getting fatter and fatter?

    I was watching a television show about sharks on one of the cable channels, and the narrator commented that “sharks are eating machines…” and I thougt, “yeah, just like people.” That was a sudden realization, that people are eating machines too, like sharks, designed to eat anything and everything in sight.

    I also started to notice, the foods which whe crave the most, like sugar and fat and meat, are very difficult to acquire in a pre-agricultural environment. And the foods which we don’t really care much for, like plants mateiral and vegetables, are easily accessible in a pre-agricultural environment.

    We have a built-in craving for food that is hard to get, and we have a take-it-or-leave-it feeling about abundant food. Now, all food is easy to get. We can eat as many twinkies as we want; we can eat as much meat as we want. As a result, we’re getting cloggged arteries, insulin resistence, indigestion, constipation, obesity, and in some of us at least, a guilty conscience for killing so many animals when we really shouldn’t be.

  13. #13 John B
    May 7, 2007

    One of the great themes of post-Darwinian science is the inter-relatedness of life.

    One imagines the central relationship is killing and eating.

  14. #14 speedwell
    May 7, 2007

    What you eat should not be something you feel shame or guilt for, much less fanaticism. How you take care of your body and how you feel about the cosmos should be your quiet pride.

    I became a vegetarian in order to take better care of myself, and I always used to say, “I’m not the sentimentalist vegetarian type.” But having been a vegetarian for a few years has freed me to look my food in the face, as it were, and realize that I do feel better not eating things that to me have too great a similarity to humans. I have no particular issues with feeding my obligate carnivores the meat they require to thrive. There really isn’t any choice in the matter. But it would be nice if I could source a pure, dumb lump of cultivated tissue to make their food out of.

    Was it this blog on which it was pointed out that an animal trying to get a person’s attention implied a theory of mind, that is to say, that the animal had enough mind to understand that there was an attention to get? I have caught my cats telling lies; I’ve taught a dog I once had to speak three words and used them correctly; I’ve seen a pair of African grey parrots share a joke at my expense; I’ve even been recognized by and received affection from a chicken. I’m still not a sentimentalist about animals. But I’m a sucker for the thing we all have in common, which for lack of a better word we can call “humanity.”

  15. #15 speedwell
    May 7, 2007

    “…used them correctly…” s/b “…use them correctly…”

  16. #16 marcj
    July 26, 2007

    It’s worth making a distinction here between “pain” and “suffering”. Pain is a sensation in the now. Suffering is an ability to reflect on either the experience of that pain in the past or in the future. An unconscious animal can experience pain, but as the theory goes, doesn’t ever suffer (it does show behavioral evidence of pain aversion and avoidance but that is another matter, as the theory goes). So: is it wrong to eat an animal that has lived all its life in its natural environment, simply because right at the end of its life it experiences pain as it dies (e.g., by a hunter with a gun)? Or is it wrong only when the animal experiences ongoing suffering (living in a cage, force feeding, treated with hormones that messes with its endocrine system, etc)?

    More to the point, if the animal cannot experience suffering, then the ethical quandary is moot – pain is only experienced in the immediate sense of when it is happening, but unless the animal suffers consciously (and there is by no means any conclusive evidence that animals are conscious in this sense), then you can do what you will to the animal while it’s alive.

    Speaking as a vegetarian, I don’t eat meat because it messes up the environment and puts farmers out of jobs. The idea that you shouldn’t eat cute animals because it’s mean just never made sense to me.

  17. #17 Brian
    May 4, 2011

    We are indeed just like other animals, even in the sense that animals eat other animals…