I say no, despite what "experts" in sociology and psychology may think. These two forms of science are ever changing, ever evolving, since really the data is subjective, not physical, such as in chemistry or other physical sciences. Also, my son, step son, best friend, wife, and a whole host of other people play violent video games all the time. If it was such a contributing factor to real world violence, there would be hundreds of thousands of cases a day. That data is actually objective as well. If a person is moved to commit violent acts because of a video game, or music, or whatever, then they were prone to violence to begin with and not wrapped too tight (or if you prefer, a few french fries short of a happy meal).