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.

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.

By sort of combining the research of a lot of smart people, I came up with an equation for dread [dread=uncontrollability+unfamiliarity+imaginability+suffering+scale of destruction+unfairness]. The dread equation is a simplification, but it's a way to explain why we fear something so much when it is so unlikely. Part of it is the lack of control. That's why we're more scared of plane crashes than car crashes even though we know rationally which is more dangerous.

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.

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.

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.

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.