It was an analogy that went like: Graphic violence is to aggression what smoking is to lung cancer. As in risk factor of similar magnitude to entirely different thing. Personally, I believe that it is true as it makes sense.

In a society, where there are no violent movies, video games and TV series, the youth would not learn the model for the violent behaviour from the video games, movies and TV series. Therefore, they aren't as likely to behave aggressively. However, the violent behaviour can be learned from other contexts as well.