I can't tell you how many times I've been with very smart, knowledgeable Homeland Security experts who are essentially tasked with saving your life who do not trust you with information. They just don't. They kind of dismiss the media and the public in one fell swoop.

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.

Well, there isn't any one profile of a survivor, but there are profiles. Depending on the disaster you have certain advantages and disadvantages just based on who you are. Women are more likely to survive hurricanes. In hurricanes the deaths come from floods and people driving through high water. That's much more likely to be a man who dies that way.

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.

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.

We don't talk about that at all as a country. I think that most people assume that there's nothing they could do if a nuclear bomb went off in their city. And that's just not true. Most people would survive most terrorist nuclear attacks because the bombs would likely be much smaller than those we were dealing with in the Cold War.

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.