Not so long ago I was giving a presentation to a group of academics. I was talking about my new book, of which more in moment, and realised I was getting a frosty reception. It was the bit where I was talking about James Surowiecki’s book The Wisdom of Crowds and I realised, as the discussion progressed, that my critics regarded this as a rather right-wing text. Considering myself a left-leaning liberal this worried me.

In the book Surowiecki argues that humans are collectively smart. He starts with the example of a “guess the weight of a hog” competition at a country fair. Even though none of the hundreds of people in the crowd guessed the correct weight of the hog, the average of all of the guesses is almost always right, almost like humans have a collective intelligence. In the book he sets out the conditions that need to be in place for this to work. The crowd must contain a diversity of opinion and must be drawn from range of backgrounds – everyone thinking the same way is not a good thing. Individuals need to come to their view of their own accord without being told what to think or unduly influenced by ideology. Finally there needs to be a mechanism to aggregate the collective view. The most common mechanism to do this is, of course, the free market: hence the frostiness of my academic audience. However my point was that humans have created exactly these conditions in cities. Indeed it could be argued that this is the very reason that cities exist, to make us collectively smarter than we are as individuals.

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