This iconoclastic book demonstrates that irrationality exists on a startling and hitherto unsuspected scale, analysing its causes in detail by drawing on many fascinating psychological experiments. Its theme is illustrated by descriptions of scores of irrational decisions taken by soi-disant experts such as generals, doctors and civil servants: their errors demonstrate the high cost of irrationality to society. The author also discusses the broader social and emotional causes of irrationality, and its roots in our evolutionary history and the structure of (...) our brains. He devotes a remarkable chapter to the current obsession with the paranormal, one of the most clear cut manifestations of contemporary irrationality. Each chapter ends with brief precepts showing how to avoid the types of irrationality set out within it. (shrink)