For example, societies which experienced a lot of war are not more violent societies. Actually, my experience is that seeing violence makes you less violent. Is that possible?
My second comment is about violent games...
Video games of any type are not good for kids. Not because of violence, sex and other things. It is because they don't go out to socialize. My theory is that instead of limiting "what to watch / play", parents should more focus on limiting "how much to watch / play".