In his latest Wired column, Bruce Schneier explains why asking science fiction writers to come up with fanciful terrorism scenarios is dumb.
I discounted the exercise at the time, calling it "embarrassing." I never thought that 9/11 was a failure of imagination. I thought, and still think, that 9/11 was primarily a confluence of three things: the dual failure of centralized coordination and local control within the FBI, and some lucky breaks on the part of the attackers. More imagination leads to more movie-plot threats — which contributes to overall fear and overestimation of the risks. And that doesn't help keep us safe at all…
Fascinating stuff. But the biases produce the reverse effect when it comes to movie-plot threats. The more you think about far-fetched terrorism possibilities, the more outlandish and scary they become, and the less control you think you have. This causes us to overestimate the risks.
Think about this in the context of terrorism. If you're asked to come up with threats, you'll think of the significant ones first. If you're pushed to find more, if you hire science-fiction writers to dream them up, you'll quickly get into the low-probability movie plot threats. But since they're the last ones generated, they're more available. (They're also more vivid — science fiction writers are good at that — which also leads us to overestimate their probability.) They also suggest we're even less in control of the situation than we believed. Spending too much time imagining disaster scenarios leads people to overestimate the risks of disaster.