The Wisdom of Crowds

Smart people often believe that the opinion of the crowd is always inferior to the opinion of the individual specialist. Philosophical giants such as Nietzsche thought that "Madness is the exception in individuals but the rule in groups". Henry David Thoreau lamented: "The mass never comes up to the standard of its best member but on the contrary degrades itself to a level with the lowest member." The motto of the great and the ordinary seems to be: Bet on the expert because crowds are generally stupid and often dangerous. Business columnist James Surowiecki’s new book The Wisdom of Crowds explains exactly why the conventional wisdom is wrong.

The fact is that, under the right circumstances, groups are remarkably intelligent, and are often smarter than the smartest people in them. Groups don’t even need to be dominated by exceptionally intelligent people in order to be smart. Even if most of the people within a group are not especially well-informed or rational, it can still reach a collectively wise decision. Why? Because, as it turns out, if you ask a large enough group of diverse, independent people to make a prediction or estimate a probability, and then average those estimates, the errors each of them makes in coming up with an answer will cancel themselves out. Not any old crowd will do of course. For the crowd to be wise it has to satisfy four specific conditions, but once those conditions are met, its judgment is likely to be accurate.

Surowieki concentrates on three kinds of problems. The first are cognition problems (problems that are likely to have definitive answers, such as: "How many books will Amazon sell this month?"). The second are problems of coordination (problems requiring members of a group to figure out how to coordinate their behaviour with one another) and the third are problems of cooperation (getting self-interested, distrustful people to work together-- despite their selfishness). The brilliant first half of the book illustrates this theory with practical examples. The second half of the book essentially consists of case studies with each chapter talking about the way collective intelligence either flourishes or flounders. Much of this part deals with business topics such as corporations, markets and the dynamics of a stock-market bubble.

Surowieki has an engaging, direct style defending his surprising central thesis in entertaining ways by, for example, talking about laying bets on football games and political elections; traffic jams; Google; the Challenger explosion and the search for a missing submarine. The Wisdom of Crowds is an entertaining book making a serious point and by the end of the superb first half the reader has been made to accept that, while with most things, the average is mediocrity, when it comes to decision-making the average results in excellence.