There are few areas where skepticism is more important than how one invests one's life savings. Yet intelligent and educated people, some of them naïve about finance and others quite knowledgeable, have been ruined by schemes that turned out to be highly dubious and quite often fraudulent. The most dramatic example of this in American history is the recent announcement that Bernard Madoff, a highly regarded money manager and a former chairman of Nasdaq, has for years been running a very sophisticated Ponzi scheme, which by his own admission has defrauded wealthy investors, charities and other funds of at least $50 billion.
Financial scams are just one of the many forms of human gullibility -- along with war (the Trojan Horse), politics (WMDs in Iraq), relationships (sexual seduction), pathological science (cold fusion) and medical fads. Although gullibility has long been of interest in works of fiction (Othello, Pinocchio), religious documents (Adam and Eve, Samson) and folk tales ("The Emperor's New Clothes," "Little Red Riding Hood"), it has been almost completely ignored by social scientists. A few books have focused on narrow aspects of gullibility, including Charles Mackey's classic 19th-century book, "Extraordinary Popular Delusion and the Madness of Crowds" -- most notably on investment follies such as Tulipmania, in which rich Dutch people traded their houses for one or two tulip bulbs. In my new book "Annals of Gullibility," based on my academic work in psychology, I propose a multidimensional theory that would explain why so many people behave in a manner that exposes them to severe and predictable risks. This includes myself: After I wrote my book, I lost a good chunk of my retirement savings to Mr. Madoff, so I know of what I write on the most personal level.