THE IMPROBABILITY PRINCIPLE

Enlightening and entertaining explanation of why extraordinary events are to be expected.

Former Royal Statistical Society president Hand (Emeritus, Mathematics/Imperial Coll., London; Statistics: A Very Short Introduction, 2008, etc.) is an erudite but utterly unpretentious guide to the often confusing and counterintuitive subject of probability and its underappreciated complement, improbability. He explains why we should not be surprised, for example, when some people win lotteries or are hit by lightning multiple times, despite the odds against either event happening to any single person even once being vanishingly small. Chapter by chapter, Hand pieces together the threads of what he calls the “Improbability Principle,” showing that if something can happen, given enough time and enough opportunities (according to the law of very large numbers), it will happen. But he also reveals that extraordinary events which, in theory, are highly improbable or even impossible, usually prove, upon closer inspection, to have “probability levers” that raise the odds they will happen: Roy Sullivan was struck seven times by lightning, which would seem fantastical if you didn’t know he was a forest ranger. “The Improbability Principle tells us that events which we regard as highly improbable occur because we got things wrong,” writes Hand. “If we can find out where we went wrong, then the improbable will become probable.” Without taxing casual readers with strenuous math, the author coolly examines many fascinating examples of the unlikely, including odd coincidences—as when actor Anthony Hopkins found a copy of the book his next film project was to be based on in an empty seat on a subway train and learned weeks later that the copy belonged to a friend of the book’s author who was preparing an American edition—hot streaks in sports, ESP research, C.G. Jung’s accounts of synchronicity, and even the origins of life and the universe.

Ably and assuredly demystifies an ordinarily intimidating subject.