Non-experts are constantly called upon to assess life-threatening situations. Some are very common and foreseeable (should I have a fourth spiked eggnog before I drive home?), some less common (will I get robbed in broad daylight in the mall parking lot?) some are very uncommon (will an airplane crash into my house?).

There are, of course, varying levels of expertise that people may have while assessing these situations. It certainly would be nice to have an expert make these assessments, but most of the time that's not feasible.

It behooves us to get better at threat assessment. Bruce Schneier's book Beyond Fear: Thinking Sensibly about Security in an Uncertain World was written for my industry but is the best treatment of how bad humans are at threat assessment that I've yet read.