The evil genius of terrorism is that that maximizes unfamiliarity, imaginability, suffering, scale of destruction, unfairness. It's really important to understand why terrorism is so frightening because it is a psychological war and until you understand it and try to reduce the dread, until then you become like a force multiplier for the terrorists inadvertently because you'll tend to overreact to terrorist attacks because the dread factor is so high.

People will help each other because there is a sense of camaraderie that springs up, which is a survival tactic. You help them because you know you might need their help later. And that is incredibly reassuring.

The public totally discounts low-probability high-consequence events. The individual says, it's not going to be this plane, this bus, this time.

Women are far more likely to follow orders to evacuate, especially women with children. At the same time, women were much more likely to die during the South Asian tsunami. In some villages it was 3 to 1. And that was party because of the average strength it takes to hold onto something. Also it was cultural; women were less likely to know how to swim, as were children. So much of this is based on how we develop our own survival skills before something goes wrong: Even if nothing goes wrong, it might be good to know how to swim.

The evil genius of terrorism is that that maximizes unfamiliarity, imaginability, suffering, scale of destruction, unfairness. It's really important to understand why terrorism is so frightening because it is a psychological war and until you understand it and try to reduce the dread, until then you become like a force multiplier for the terrorists inadvertently because you'll tend to overreact to terrorist attacks because the dread factor is so high.

People help way more than we expect, way more than makes sense. But when you talk to people called heroes, they often say they did it for themselves. In one case, a hero said that the cost of not doing it is so great, the sense of shame, when he knew that he was strong enough, that the fear of not doing anything was more frightening than the fear of dying.

Women in particular seem to say things like, "I'm sure I'd be the one screaming and not moving in an emergency." I don't think that's the case. People who've been through really horrible life-or-death situations say that nobody behaves the way they would have expected. But that said, there are predictors.