Despite anecdotes and myths to the contrary, a particular variety of alcohol isn't really any different than another. Vodka is no more likely to make a person violent than bourbon, beer, whiskey, or any other alcohol. It's the person who determines the behavior, not the beverage.
Any alcohol could make someone violent, if they have this tendency. The type of alcohol does not matter for this; vodka is no more or less likely to do so.
Vodka doesn't make everyone violent, no. However, if a person with an aggressive personality drinks a lot of it, there is definitely a risk for heightening that trait. Vodka is not the only liquor that will do this to you.
Vodka itself does not make a person violent. If a person has violent urges the alcohol of any type make cause these feeling to come to the surface. Alcohol lowers a person inhibitions.
In my experience different types of alcohol causes different reactions in different people. However, if a person is already violent, vodka can certainly make it worse.