Priming

          I think that the theory of priming is definitely something that if it is true, would be hard to prove. Priming Theory is a theory that basically states that once someone sees something, they're likely to repeat it. I, personally, have been playing video games and watching violent movies and TV my entire life, but I have never gone out and reenacted things that I've seen. It may affect some people but I would be willing to bet that a good majority of people use those things as a release and not as a way to get new awesome finishing moves.

          This article: http://videogames.procon.org/, states that there are many articles and studies that link video games to increased violence, but there are also many things that contradict this statement. It lists many results found by these studies. Unfortunately whenever studies are trying to find out if video games are linked, they don't usually look at the casual games and the impact that they have. No one has all horribly violent video games and if they do, that was a product of something else entirely, like people bullying you, or abuse at home.