John Walsh: Killers aren't created by what's on TV

The horrific details of how Daniel Bartlam murdered his mother with a claw hammer must have been music to the ears of the anti-video-games lobby. It seemed that the teenager's homicidal onslaught can be held up as proof – at last! – that the depiction of violence leads to acts of violence.

Daniel was obsessed with a Coronation Street character who attacked a woman with a hammer. Daniel was a connoisseur: he pored over TV footage of violent soap scenes; he'd watched horror films since he was eight; he watched one of the torture-porn Saw films hours before the murder.

So has the prosecution won? Can we accept that there's a direct correlation between fictional and real-life mayhem? In a week when another American campus killing claimed seven lives, can we blame it on too much exposure to shopping-mall videos? Will it happen here?

The claim that young people receive an education in violence solely by watching dramatic representations of it, is usually made by people who think savagery and brutality aren't part of humanity. Words like "civilisation" express our attempts to rein in our savage instincts. Moral education, religious belief and fear of legal redress keep us (mostly) from taking the law into our own hands.

We may have "civilised" ourselves down the centuries, but a vestigial liking for confrontation, excitement, revenge, and violence lurks inside us still. We love its reification in sport, and its depiction in EastEnders. It's the reason little boys like to thump each other in playgrounds and fling themselves from play cars. And watch Call of Duty. But it doesn't turn them into killers.

When I was a kid in the 1950s, we played war games all the time. We loved war films without becoming violent ourselves. Violence was a subject for art (and play) but art didn't breed individual violence. What bred violence in the individual was a bullying sergeant and lots of rhetoric about duty.

What makes us violent is something else. When the printers of American Psycho refused to touch the book on the grounds that it was "a how-to guide to the dismemberment of women", they missed the point. They confused terrible knowledge with terrible will. Depictions or dramatisations won't make us muggers, thieves or killers unless we have the will to be so. Daniel Bartram was a once-in-a-blue-moon example of someone who had.