The Science of Fear covers many areas that have people scared: pedophiles, kidnappers, terrorists, nuclear holocaust, global warming, and virtually everything in between is covered.
Gardner discusses the scientific explanation for why our brains latch onto extremely unlikely but terrifying possibilities, and why we tend to ignore the much more likely but less exotic. The science presented is sound, well-backed by studies and experiments.
Gardner also explores the reasons why we are presented with the information we are. Why the media, politicians, and marketers all try to make us afraid of things that have vanishingly small probabilities.
Overall, its a very interesting book with well-presented information. Much better than Bozo Sapiens (which I just read before it) which dealt with much of the same material, but not as good as Beyond Fear by Bruce Schneier, which deals with the same aspect of humanity though covers the science with far less depth.