The Drunkard's Walk: How Randomness Rules Our Lives

First, if you are bad at math,like me, most of this book is beyond reach or can at best be half understood. While he writes well, and makes a great effort to be clear, his talents can't overcome my brain wiring.(I have read over the Monty Hall deal three times and still don't get it). But when my knowledge and his explanations sync, there are great insights : regression to the mean(in any series of random events an exrtraordinary one is most likely to be followed by an ordinary one by chance; the insight is used in explaining how we confuse cause and effect); good thoughts on availability and confirmation bias; thoughts on why some businesses do well and others do not(same territory as "The Halo Effect"). But the gem is the last chapter, its title the same as the book's, where he says:give yourself a break, stuff happens both bad and good for no reason other than it does, but never forget that success may come your way if you are open to the universe and keep swinging away. "What I've learned , above all, is to keep marching forward because the best news is that since chance does play a role, one important factor in success is under our control: the number of at bats, the number of chances taken, the number of opportunities seized...or as IBM pioneer Thomas Watson said,"If you want to succeed, double your failure rate." The chapter is worth the price of the book.

this is a great book, but it made my brain hurt.

basically, the drunkard's walk is a history of the mathematical study of randomness, including physics, probability, normal distribution, and other concepts. but, really, it's a look at the role that randomness plays in our lives, and how most things are quantifiably less random than they may seem.

there were dozens of times, while reading, that i thought, that makes complete sense, but i can't imagine that i'm going to remember it. this was often because the proof of the theory made sense at an objective level when explained, but was counter-intuitive to real life and regular ol' human thinking. a great example of this is the author's extended explanation of the marilyn vos savant "let's make a deal" problem. marilyn vos savant writes a column in parade magazine where she answers questions from readers, using her "world's record highest iq". she famously responded to a question, years ago, that posed this problem:
if a contestant on "let's make a deal" (the 70s game show) were given three doors to choose from, and told that a new car was behind one of them, and lousy prizes behind the other two; then, after choosing a door, and having monty hall reveal one of the remaining doors as a loser prize and given the opportunity to shift choice on the remaining two, should the contestant make the change? her response was that, statistically -- yes, the odds are better if the contestant changes her answer.

people freaked at her response, including lots of professional mathematicians, who (wrongly) argued that, with two remaining choices, the chances are still 50/50 that the car is behind the door of the contestant's original choosing.

the proof of this fallacy is all based on probability computations. the contestant's original choice had a 33% chance of being correct -- or 1 in 3. but monty hall removed one of those three (knowing which doors had the good and loser prizes). so, sticking with the original choice still leaves the original probability of 1 in 3. but changing choices raises the probability to 1 in 2 -- better odds.

the author acknowledges that while this kind of proof is true, and mathematically observable, it's contrary to how our brains are wired to consider options.

that said, it was this kind of story - the book has hundreds of them -- and the author's wittiness, that kept me reading through the brain strain.

oh, btw, the title refers to the term scientists use to describe the path of atoms and sub-atomic particles -- seemingly random as they carom off each other in a willy-nilly path. ultimately, this path is not actually random, but is merely beyond our ability to compute, based on the absurd quantity of possibilities rising from interactions with other moving particles.

An intriguing book with fresh perspectives. While being entertaining to read, it is simultaneously very thought-provoking and informative with fascinating "historical background side trips" that add color, depth, and interest to the chapters.

I personally found it extremely insightful. It offers more than a simple explanation of probability and how randomness can affect our lives. It is so thought-provoking as to inspire (me anyway) to review fundamental assumptions about the world and my place in it.

It is not for those who are unprepared to examine personal assumptions about how life works-- some grounding in the statistical sciences would probably be a good background as well. Nevertheless, I would encourage any thoughtful, inquisitive person to read this book. Easily one of my favorites of all time.

Instead of repeating other reviewers, let's focus on other content.

Arguments about the astronomical improbably of a DNA chance match are disingenuous. A false match can also occur because of lab error, and this is far, far more likely than a genuine DNA chance match.

Mlodinow illustrates the Bayesian principle: "...the probability that A will occur if B occurs will generally differ from the probability that B will occur if A occurs." (p. 117) About 1 in 10,000 heterosexual non-IV-drug-abusing white males are infected with HIV. As for tests of HIV infection, the rate of false negatives is about zero, and that of false positives is 1 in 1,000. So, out of 10,000 tested subjects, there will be 9, 989 negatives. Of the 11 positives, 10 will be false and 1 will be true. So only 1 in 11 individuals who test positive for HIV actually are infected with HIV. (pp. 115-116)

During WWII, German V-2 rockets often hit near each other, prompting fears that the Germans had perfected pinpoint accuracy in their targeting. It turned out that the clusters of hits were random. Most geographical clusters of cancer occurrence also are random clusters.

We learn about such things as regression toward the mean, Pascal's wager, the gambler's fallacy, and the scratched (and therefore biased) roulette wheels at Monte Carlo. Also, election recounts in very close elections are bound to differ with each recount owing solely to small random errors operating on millions and millions of votes. So no recount is necessarily more accurate than the original count.

Life expectancy applies to groups, not individuals. For instance, if the life expectancy of a 90 year-old is 6 years, it only tells us that half of 90-year olds will still be alive at 96. It does not tell us which particular 90 year-old individual will still be alive at 96.

When there are hundreds of coin tosses, it is common for strings of consecutive "heads" and "tails" to arise solely by chance. Likewise, a string of good luck or bad luck in our lives can be completely random, yet easily misinterpreted as something meaningful.

When experimental subjects are told that, by pressing a button, they are controlling actually randomly-flashing lights, they readily believe it. We want to believe that we are in control because a lack of control, or perceived lack of control, leads to stress. This is especially true in extreme situations. For instance, concentration-camp victims who survived tended to be those who established some measure of control over their horrible experiences.

This is a wonderful book for the non-technical person. It's more than just a discussion of random processes. It's a history of how the theory was developed over several hundred years, the fundamental laws upon which the theory is based, and a sprinkling of problems the solution of which defy common sense. Mr. Miodinow is trained as a scientist, but has a style of writing that is similar to some of the great authors of science like Richard Fynman and Carl Sagan who wrote books for the layman. A must read book by all.