Does violence in the media lead to real-life aggression?

Media violence has been a topic of debate without definitive answers for many years. The primary question of focus seems to be whether or not media violence actually causes real-life violence

Of course, many factors could contribute to this, such as personality traits, the perception of 'reality' of media violence and so on. Increasingly the debate is focusing on the "culture of violence," and on the normalization of aggression and lack of empathy in our society. Indeed it seems that the more violence we view, the more desensitised we become. I myself being a romantic comedy and drama movie lover, find it quite hard to witness gruesome shooting scenes in action movies and thrillers, and i avoid horror films all together!

However the fact remains that frequent exposure to any variety of originally offensive material such as drug use, sex scenes, course language etc seems to reduce the shock factor of the content. Any comments on this phenomenon?

Food for thought: