Drunkard's Walk - Leonard Mlodinow [82]
But to believe that a social physics exists is one thing, and to define one is another. In a true science, Quételet realized, theories could be explored by placing people in a great number of experimental situations and measuring their behavior. Since that is not possible, he concluded that social science is more like astronomy than physics, with insights deduced from passive observation. And so, seeking to uncover the laws of social physics, he studied the temporal and cultural variation in l’homme moyen.
Quételet’s ideas were well received, especially in France and Great Britain. One physiologist even collected urine from a railroad-station urinal frequented by people of many nationalities in order to determine the properties of the “average European urine.”25 In Britain, Quételet’s most enthusiastic disciple was a wealthy chess player and historian named Henry Thomas Buckle, best known for an ambitious multivolume book called History of Civilization in England. Unfortunately, in 1861, when he was forty, Buckle caught typhus while traveling in Damascus. Offered the services of a local physician, he refused because the man was French, and so he died. Buckle hadn’t finished his treatise. But he did complete the initial two volumes, the first of which presented history from a statistical point of view. It was based on the work of Quételet and was an instant success. Read throughout Europe, it was translated into French, German, and Russian. Darwin read it; Alfred Russel Wallace read it; Dostoyevsky read it twice.26
Despite the book’s popularity, the verdict of history is that Quételet’s mathematics proved more sensible than his social physics. For one thing, not all that happens in society, especially in the financial realm, is governed by the normal distribution. For example, if film revenue were normally distributed, most films would earn near some average amount, and two-thirds of all film revenue would fall within a standard deviation of that number. But in the film business, 20 percent of the movies bring in 80 percent of the revenue. Such hit-driven businesses, though thoroughly unpredictable, follow a far different distribution, one for which the concepts of mean and standard deviation have no meaning because there is no “typical” performance, and megahit outliers, which in an ordinary business might occur only once every few centuries, happen every few years.27
More important than his ignoring other probability distributions, though, is Quételet’s failure to make much progress in uncovering the laws and forces he sought. So in the end his direct impact on the social sciences proved modest, yet his legacy is both undeniable and far-reaching. It lies not in the social sciences but in the “hard” sciences, where his approach to understanding the order in large numbers of random events inspired many scholars and spawned revolutionary work that transformed the manner of thinking in both biology and physics.
IT WAS CHARLES DARWIN’S FIRST COUSIN who introduced statistical thinking to biology. A man of leisure, Francis Galton had entered Trinity College, Cambridge, in 1840.28 He first studied medicine but then followed Darwin’s advice and changed his field to mathematics. He was twenty-two when his father died and he inherited a substantial sum. Never needing to work for a living, he became an amateur scientist. His obsession was measurement. He measured the size of people’s heads, noses, and limbs, the number of times people fidgeted while listening to lectures, and the degree of attractiveness of girls he passed on the street (London girls scored highest; Aberdeen, lowest). He measured the characteristics of people’s fingerprints, an endeavor that led to the adoption of fingerprint identification by Scotland Yard in 1901. He even measured the life spans of sovereigns and clergymen, which, being similar to the life spans of people in other professions, led him to conclude that prayer