What is the impact of regular excercise or smoking on the chance of having a heart attack? Is the difference between the average income of the top ten percent and the bottom ten percent of Americans widening? Topics like these are staples of news articles every day, but they were only made possible by a revolution in thought that occurred during the nineteenth century--the rise in statistical thinking--that Porter's book recounts. The story of the introduction of the scientific method in the 17th century is familiar. The discovery of the laws of probability by Pascal--prompted by a friend's interest in solving a gambling problem--has also been presented in several books. But the habit of thinking numerically about populations only arose in the 19th century, and this story is less well known.
It was during the 19th century that it became common to examine the characterists of populations, for example, the average number of suicides, deaths, or crimes each year. The mathematical concepts that are now taught to most high school and college students--mean, median, the normal distribution or bell curve, and correlation--were developed by the end of the century.
By stressing the broader intellectual context of these developments, Porter highlights some interesting perspectives. For example, statistics was the province of reformers who believed that government neither could, nor should, do much to change society. Also, I hadn't realized the importance of Darwin's theory--and its bastard child, eugenics--as a motivation to so many statisticians.
Statistical concepts were developed by social scientists, and only later adopted by physical scientists. This reverses the more common 'physics' envy, where social scientists see the physical sciences as the gold standard and attempt to copy their methods.
Although his topic is fascinating, Porter's book is not, at least for the nonspecialist. Porter's academic prose rarely made the subject come alive, and I found myself soldiering on and waiting eagerly for the last page.
One problem was that Porter never explains any of the concepts he discusses, assuming that the reader is familiar with them. In my case, that was fine for basic statistical concepts like standard deviation and regression, but I was lost in many other places, such as his discussion of the theory of gases.
As an alternative, Ian Hacking's book, The Taming of Chance, is a discussion of the philosophical implications of many of these developments (although it doesn't cover Galton, Edgeworth, and Pearson). I found it gripping throughout, and it is extremely well written, at least for an academic.
