I was in Colorado the week James Holmes walked into an Aurora movie theatre, showing The Dark Night Rises and allegedly murdered 12 and injured 58 people with an assault rifle. With hair dyed red he apparently modeled himself on the film’s sadistic villain – The Joker. The aftermath has reawakened the debate about gun control in a country where there are 88 guns for every 100 people.

What fewer people are talking about is the role of violent stories in all of this. Some Hollywood executives have claimed that violent entertainment actually reduces aggression by providing a cathartic outlet. Yet at least a hundred studies have conclusively demonstrated the opposite. Screen violence increases aggression particularly in children where it often induces copycat behaviour. Of course stories affect our actions, if they didn’t why would companies spend billions on the short sales stories we call adverts?

In my book The Astonishing Power of Story I explain just why stories are so powerful. You know how sometimes when you’re watching a film or reading a book you feel as if you’re the hero? That has to do with a part of the brain called the Mirror Neuron Network. You watch someone hit their finger with a hammer and you wince, that’s another example of how the mirror neurons internalize others’ experience as if it is our own. With our mirror neurons we don’t just watch stories, we live them and that can change us when we go back to our own lives. We’re not robots, we’re not going to act out everything that we see but if we’ve just “mirrored” a character successfully solving a problem with aggression, we may become primed to see aggression as a solution to our own problems. Stories provide virtual role models that can be a catalyst for bad or good. They certainly can do a lot of good.

President Ronald Reagan credited a fictional Hollywood movie called The Day After for changing his mind on nuclear war policy and leading to the destruction of nearly 3000 nuclear weapons. The film Pay it Forward led to a major philanthropic foundation that has funded hundreds of projects supporting schools and hospitals besides spurring countless random acts of kindness. Audiences of the The Kite Runner paid for 70 rural libraries and 500 laptops in Afghanistan. Blood Diamond propelled the diamond industry to educate consumers on conflict-free diamonds. These were all fictional stories that spurred people to take positive action.

Using the power of story, my new book Quest, Inc. seeks to inspire and equip readers to improve their lives. I’m currently in Hollywood meeting with producers to turn the book into a television drama series. Sure, all those cop, lawyer and police dramas can be fun by why not a show about the high end coaches who change people’s lives? If we’re going to watch drama wouldn’t we be better off “mirroring” characters taking heroic action to improve their lives?

James Holmes, the man who modeled himself on the Joker, never shot up an Aurora theatre because he watched a Batman film. That would negate his responsibility. But study after study suggests that it probably contributed. So, as writers and producers what stories are we going to create, and as readers and viewers, what stories are we going to entertain?