Mental Illness and Violence: The Lack of a Link

Vaughan Bell of the excellent Mind Hacks blog has an important article up at Slate. It's an attempted prophylactic to media speculation in the recent Gabrielle Giffords shooting about the mental state of suspected gunman Jared Loughner.

Despite advances in public understanding about mental illnesses, there are still pervasive misconceptions, especially when it comes to safety and violence. To wit:

If you found evidence on the Web that Jared Lee Loughner or some other suspected killer was obsessed with soccer or football or hockey and suggested it might be an explanation for his crime, you'd be laughed at. But do the same with "schizophrenia" and people nod in solemn agreement. This is despite the fact that your chance of being murdered by a stranger with schizophrenia is so vanishingly small that a recent study of four Western countries put the figure at one in 14.3 million. To put it in perspective, statistics show you are about three times more likely to be killed by a lightning strike.

It's easy to ignore the common causes of violence (like alcohol or heightened emotions at sporting events) in part because they're so common -- no one gives it a second thought, and it's very unlikely to get on the news. However, whenever there's a rare but highly publicized incident of violence linked with a person with a mental illness, our confirmation bias kicks in to say, "See? I knew it all along -- he had to be crazy." There's a comparison to be made here with auto and airplane death rates, but I'll let you connect those dots.