Mind & Brain See Inside Knowing Your Chances: What Health Stats Really Mean Learn how to put aside unjustified fears and hopes and how to weigh your real risk of illness—or likelihood of recovery By Gerd Gigerenzer, Wolfgang Gaissmaier, Elke Kurz-Milcke, Lisa M. Schwartz and Steven Woloshin Jim Craigmyle / Corbis In a 2007 campaign advertisement, former New York City mayor Rudy Giuliani said, “I had prostate cancer, five, six years ago. My chances of surviving prostate cancer—and thank God, I was cured of it—in the United States? Eighty-two percent. My chances of surviving prostate cancer in England? Only 44 percent under socialized medicine.” Giuliani used these statistics to argue that he was lucky to be living in New York and not in York. This statement was big news. As we will explain, it was also a big mistake. In 1938 in World Brain (Methuen & Co.), English writer H. G. Wells predicted that for an educated citizenship in a modern democracy, statistical thinking would be as indispensable as reading and writing. At the beginning of the 21st century, nearly everyone living in an industrial society has been taught reading and writing but not statistical thinking—how to understand information about risks and uncertainties in our technological world. That lack of understanding is shared by many physicians, journalists and politicians such as Giuliani who, as a result, spread misconceptions to the public. This is only a preview. Get the rest of this article now! Select an option below: Buy Digital Issue Customer Sign In *You must have purchased this issue or have a qualifying subscription to access this content It has been identified that the institution you are trying to access this article from has institutional site license access to Scientific American on nature.com. Click here to access this article in its entirety through site license access. ADVERTISEMENT Scientific American is a trademark of Scientific American, Inc., used with permission © 2015 Scientific American, a Division of Nature America, Inc. All Rights Reserved.