We gauge risk literally hundreds of times per day, usually well and often subconsciously. We start assessing risk before the disaster even happens. We are doing is right now. We decide where to live and what kind of insurance to buy, just like we process all kinds of everyday risks: we wear bike helmets, or not. We buckle our seatbelts, smoke cigarettes, and let our kids stay out until midnight. Or not.

The one thread that was most surprising and most consistent was the lack of fear that people felt at the worst moment. They felt a lot of fear in early stages, when they're just realizing what's happening. But then things really seemed to be at their peak of terror, the fear went away. You can imagine why that's useful. At that moment your brain needs to focus all its attention on surviving, so people will feel a sense of calm as their brain tries to sort out a plan.

People with military experience seem to do very well in these situations. They've been taught that they can control their destiny, which is half the battle. They also have some experience in getting out of bad situations even if just through training. They know they have to make a plan and follow it and execute it.

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.

Most serious plane crashes are survivable. There's a sense that, 'Oh, if we go down, that's it, it's out of my hands.' And that's just statistically not true. I have more optimism and more faith that my own actions can make a difference.

A lot of the time you see a warning, in the subway, or in a movie theater, the main thrust of the warning will be to not panic if there is an emergency. To listen to directions. Now that's a waste. They could have given you information, but you can see their expectation that you're going to screw up.