I eat meat, and I know people who eat meat, and they and I can can be the most gentle people I or you have ever met. It is odd also, to say more violent. In what ways more violent? How much of an increase? 1%, 25%, or is 1.23% -/+ 4% variable going to empower this argument? Is it just violent thoughts or actions? What constitutes a violent action? I think I have more violent thoughts than acts of violence.
In my life, I have known very few pure vegetarians. They all have been extremely kind and wonderful people, gentle, smart and considerate. Who is to say they have not always been this way and this inner born in natural demeanor is what led them to a vegetarian life style?
I think ones outlook on life is what most determines the actions they have in response to input/stimulus. Ones mind and how they frame events determines their response. If one thinks eating meat makes you angry and violent, then that is most likely going to be the outcome. The placebo effect is very powerful and effective. That means the mind is in control of the outcome most of the time all the time.
So how are you framing this debate? Are you mad about people eating meat? What stories are you telling yourself about those who eat or do not eat meat, and how they behave?
Meat contains many things that help people function well on a physiological level. Essential fats for cell and neuron functioning. Protein for cellular repair, and iron for blood production which is essential for oxygen delivery within the body. Some of these things are available from just plant sources, but at a much higher calorie cost and it is much harder on the body to extract these things. In his book “Catching Fire: How Cooking Made us Human”, Richard Wrangham provides a strong argument that eating cooked meat instead of raw meat or a diet of all plant based food is what encouraged our evolution from primate to the thinking understanding rational and reasoning people we are today (of course, the whole rational and reasoning thing is debatable as well).
But I digress, and am getting off topic of the question. Does it make one more violent? There are tons of so called personal experience and findings about yes it does make one more violent, but until there is adequate research studies done, this is all just opinion.