Monday, June 29, 2009

BOOKS: The Drunkard's Walk

CalTech physicist Leonard Mlodinow, in his book "The Drunkard's Walk: How Randomness Rules Our Lives", offers a fascinating lesson on the development of our understanding of probability and randomness, and how randomness is widely misunderstood and underestimated even today. The core chapters of the book present a sequence of concepts in probability theory, but rather than just present dry theory, Mlodinow takes the much more interesting approach of presenting the concepts by way of the history of their development, making it not only the story of the development of ideas, but of the colorful characters who contributed to them. Along the way, we meet a Renaissance doctor who made more money at games of chance than treating the sick, a Swiss dynasty and full-scale soap opera of mathematicians, and a mathematician who experienced a religious conversion and made a probabilistic argument for the existence of God. He does a good job of carefully explaining the concepts with good examples. Many of the examples are surprisingly counter-intuitive, such as the "Monty Hall problem", supporting the point that our brains tend to be wired counter to correct probabilistic reasoning. The book begins with a discussion about how much we may underestimate and underrecognize the role of randomness in our lives, and at the end returns to the theme of how much we misattribute success or failure to our own efforts while neglecting the role of chance. He touches on a wide variety of applications, from baseball (home run records and world series outcomes) to movie industry executive performance and mutual fund management success, illuminating how much of such outcomes are random. And he discusses some surprising psychological experiments that expose our innate tendency to find patterns in random "streaks" and to attribute intentional control over things we don't actually control (even when we know better). Not only does Mlodinow succeed in making mathematical theory and history quite fascinating, but he demonstrates the applicability of randomness in our lives in ways that will make you ponder.

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