This depends on what you mean by violent? If you ever stroll through some of the diet sites online that include blogs, you will find some of the most violent verbal punches and kicks coming from the vegan and vegetarian lot. Granted, meat takes a lot longer to process through your system than can be healthy, but I don’t think the possible resulting crankiness can really be seen as violent. While your diet can dictate a lot about you along the ways of health and longevity, your deep rooted personality is more a collection of your life experience than what you shovel in your mouth.
Hormones can be thrown out of whack for just about any reason. Certain hormones do regulate how well you handle stress, or do not handle it. A drop in some hormone can send you into a mild depression, which can be triggered by an unhealthy reaction to a type of food. However, you are at no more risk of aggressive behavior due to hormones from eating meat than a vegetarian who drank water from a bottle that sat in the car. It should insult everyone to have a creature as complex as a human being be reduced to a few factors and traits. Every human being is individual and it would take a lot more than even several “risk factors” to amount enough to single out a cause for someone’s behavior.
A lot of people try to illustrate that eating meat triggers primitive instincts within us that, at one time, enabled us to survive through tracking and hunting. While that is indeed an interesting theory, I do not believe that the end result of the hunt can trigger the beginning of said process. It would make more sense that the act of hunting would make someone much more likely to eat what they have killed. Most people nowadays buy their meat from a store, pre- packaged. The only hunting they do in order to obtain food is hunting for a parking space at the grocery store.
To wrap up, though, what you eat doesn’t alter your personality on any great, measuarable level. If you are hungry, you might become a little irritable no matter what you are hungry for. Being irritable is something you can control and take responsibility for. Some people simply do not have good control of themselves, whether they be carnivores or not.