Maybe the violence depicted in movies and books is not so gratuitous after all, despite the charges one often hears. There's now this interesting study: http://www.medicalnewstoday.com/releases/258423.php
"Perhaps depictions of violence that are perceived as meaningful, moving and thought-provoking can foster empathy with victims, admiration for acts of courage and moral beauty in the face of violence, or self-reflection with regard to violent impulses..."