A connection between animal cruelty and other forms of violence has been observed by a number of people and is often quoted in various forms.

He who is cruel to animals becomes hard also in his dealings with men. We can judge the heart of a man by his treatment of animals. - Immanuel Kant

The greatness of a nation and its moral progress can be judged by the way its animals are treated. - Mahatma Gandhi

As long as Man continues to be the ruthless destroyer of lower living beings, he will never know health or peace. For as long as men massacre animals, they will kill each other. Indeed, he who sows the seed of murder and pain cannot reap joy and love. - Pythagoras

Is there evidence for this sentiment? Specifically, is there evidence for a connection between meat consumption and violent behaviour?

  • 1
    From what I can gather in my research, there apparently is no evidence for a connection in meat consumption and behaviour, violent or otherwise. Maybe someone doing a phD could take this up :P
    – Steve
    Commented Mar 11, 2017 at 22:25
  • 1
    You mean violent behaviour other than slicing carcasses of various creatures with knives to subsequently burn them on fire and eat them on a daily basis? :D I am kidding, of course, but the bitter vegan part of me doesn't laugh. Commented Mar 11, 2017 at 23:27
  • I had a small rant about red meat creating an imbalance, but I think the more helpful comment is that while you could say you don't see many violent vegans it's probably not because skipping the meat has made them less violent but rather choosing to be less violent has made them be less violent :)
    – David S
    Commented Mar 13, 2017 at 17:57
  • "connection between meat consumption and violent behaviour" ... presumably you mean to exclude "violent behaviour towards animals" from your question?
    – ChrisW
    Commented Apr 3, 2017 at 18:06
  • @ChrisW Not entirely. Violence against pets and other "non-food" animals would be relevant, as well as violence beyond what is required to eat an animal.
    – nloewen
    Commented Apr 3, 2017 at 18:13

2 Answers 2


Generally speaking, it is very hard to make connections between nutrition as a single factor and behavior (source):

One of the more difficult problems in research on diet and behavior is how to separate nutritional from non-nutritional factors. Because food is so intimately involved with other aspects of our daily lives, it contains much more than its obvious nutritional value. Food is an intrinsic part of social functions, religious observations, and cultural rituals. Because food is a "loaded" variable, both experimenters and subjects may harbor biases about expected research outcomes. To minimize the confounding effects of these biases, double-blind procedures in which neither the experimenter nor the subjects know what treatment is given must be used.

According to this source, there is no clear evidence about meat affecting behavior:

When it comes to food and behavior, there are no clear cut answers. Meat consumption may have either positive or negative affects on behavior, or none.

However, there are some hypotheses that link meat consumption to:

  • depression:

a 2011 article published in the Dartmouth Undergraduate Journal of Science reports that food's impact on mood is individual, and may depend on all the nutrients you've eaten, as well as time of day, age and gender.

  • aggression:

Meat is a source of tryptophan, an amino acid and precursor to the feel-good chemical serotonin. Low levels of tryptophan are associated with an increase in aggression, according to a 2009 review article published in the International Journal of Tryptophan Research.

Overall, the results are mixed and it is very hard to link meat consumption as a single factor to violent behavior. So, most certainty meat consumption only cannot be considered a trigger for violent behavior.


By some ethical standpoints (not taking sides here!), buying (any)/(CAFO-raised)/(mammal) meat to consume is in itself a (by proxy) violent behaviour. It is also up to exact definition if you consider that practice animal cruelty in itself ("other than...") or if you reserve that term for abusive behaviour in some legal context.

  • This question isn't looking for ethical standpoints. It's looking for an evidence backed connection between meat consumption and general violent behavior.
    – nloewen
    Commented Mar 13, 2017 at 13:49
  • 1
    This is more of a comment than an answer.
    – Erica
    Commented Mar 13, 2017 at 14:14
  • I won't convert this to a comment yet, but as Erica said it's more of a comment than an answer. Ethical standpoints are mostly unrelated to evidence. This would go fine as an addendum to a full answer, but it can't stand on its own.
    – Riker
    Commented Mar 13, 2017 at 15:15
  • "Use comments to ask for more information or suggest improvements", says the comments text box. I can see why someone might choose an answer as a closer fit. Just saying, if we all stuck to the rules strictly no-one would contribute anything less than a research paper ;)
    – David S
    Commented Mar 13, 2017 at 17:49

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