Why does one smoker die of lung cancer but another live to 100? The answer is "The Hidden Half"—those random, unknowable variables that mess up our attempts to comprehend the world. We humans are very clever creatures—but we're idiots about how clever we really are. This entertaining and ingenious book reveals how in our quest to make the world more understandable, we lose sight of how unexplainable it often is. The result, from GDP figures to medicine, is that experts know a lot less than they think. Filled with compelling stories from economics, genetics, business, and science, The Hidden Half is a warning that an explanation which works in one arena may not work in another. Entertaining and provocative, it will change how you view the world.