QotD: Risk and perception of risk

I tell people that if it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." It's when something isn't in the news, when it's so common that it's no longer news — car crashes, domestic violence — that you should start worrying.

But that's not the way we think. Psychologist Scott Plous said it well in The Psychology of Judgment and Decision Making: "In very general terms: (1) The more available an event is, the more frequent or probable it will seem; (2) the more vivid a piece of information is, the more easily recalled and convincing it will be; and (3) the more salient something is, the more likely it will be to appear causal."

So, when faced with a very available and highly vivid event like 9/11 or the Virginia Tech shootings, we overreact. And when faced with all the salient related events, we assume causality. We pass the Patriot Act. We think if we give guns out to students, or maybe make it harder for students to get guns, we'll have solved the problem. We don't let our children go to playgrounds unsupervised. We stay out of the ocean because we read about a shark attack somewhere.

It's our brains again. We need to "do something," even if that something doesn't make sense; even if it is ineffective. And we need to do something directly related to the details of the actual event. So instead of implementing effective, but more general, security measures to reduce the risk of terrorism, we ban box cutters on airplanes. And we look back on the Virginia Tech massacre with 20-20 hindsight and recriminate ourselves about the things we should have done. In fact, the incident has been used as evidence both for and against gun control.

Bruce Schneier, "Virginia Tech Lesson: Rare Risks Breed Irrational Responses", Wired, 2007-05-17