PROOFINESS

A short course in how politicians, lawyers, advertisers and others use numbers to deceive.

Seife (Journalism/New York Univ.; Sun in a Bottle: The Strange History of Fusion and the Science of Wishful Thinking, 2008, etc.) starts with Sen. Joseph McCarthy’s claim that 207 communists were working in the State Department. The number changed over the following weeks, but once it was out there, people bought it—the apparent precision made it credible. The misuse of numbers and statistics is commonplace in our society, as the author demonstrates with plenty of absurd statistics that collapse under even the slightest examination. “Potemkin numbers”—those invented to sell a preconceived idea—are just one variety of abuse; the inherent inexactness of measurement yields many bogus numbers. The 98.6 degrees “normal” body temperature is an average based on readings of armpit temperature, rarely used by modern medicine. Similarly misleading are wild extrapolations from current data. One journal published data showing that female marathoners would at some future date post faster times than men. But women began to run the race only recently, so their records reflect a much smaller sample. Extrapolated further, those same numbers show that women runners will eventually break the sound barrier. Polls are especially subject to error, writes Seife, due to the very nature of sampling. The vaunted “margin of error” is widely misunderstood, and can hide inaccuracies the pollsters would rather not admit to. Even elections are subject to miscounting, especially in close contests such as the 2008 Minnesota senatorial race. Stacking the deck—for example, gerrymandering election districts—can also yield results that defy the popular will. Seife favors no party, giving examples of how all segments of the political spectrum deal in bogus numbers when it fits their agenda. While nothing is likely to stop the merchandising of misleading statistics and Potemkin numbers, readers of this book will at least have some protection when the next slick huckster tries to bamboozle them with fancy figures.

Sprightly written, despite its sobering message.