I have admired the articles and books that Malcolm Gladwell has published ever since he began writing for the New Yorker. At first, I was deeply impressed by the way he wrote. He is a story-teller, a good one and is able to bring alive the abstract findings of large and important areas of social science. His essays in the New Yorker are entertaining, instructive, and more often than not, concern issues of consequence.

But as the years went by, I began to worry about their appeal. I began to ask What are the special responsibilities of a science writer, one whose work is widely read and much admired? Is it enough that he popularizes the science, in most cases, findings from social psychology that he writes about? Or does the popularity of his work also call for a more critical approach to the material?

As a social scientist with a good deal of applied research experience, I thought Gladwell often simplified issues that were far more complicated than he acknowledged. I worried about the studies that he didn’t talk about and the qualifications they would place upon his claims. I was troubled by his tendency to over-generalize, as I knew his claims did not apply as widely as he implied. And then most of his essays and books consist of a series of anecdotes or case studies with little in the way of analysis. A writer doesn’t create a very deep understanding of human behavior from a cascade of entertaining anecdotes.

This has been true of his previous books, The Tipping Point and Blink: The Power of Thinking without Thinking, as well as most recent work, Outliers: The Story of Success that at this time ranks Number 1 on the New York Times List of non-fiction best sellers where it is likely to remain their for the rest of the year.

In Outliers Gladwell proposes the five-factor theory of success. He never gives an explicit definition of success. But in a very general way, it is clear what he means by the examples of extraordinary achievement he discusses--Bill Gates, Robert Oppenheimer, The Beatles, etc. According to Gladwell, the factors responsible for success these and other extremely success individuals are Talent, Hard Work, Opportunities, Timing and Luck.

Neither factor alone is sufficient to guarantee success. Nor is success necessarily preceded by any single one. But Gladwell wants us to appreciate the powerful role that past experiences, family background, and cultural traditions play in determining success. At the same time, he wishes to counter the tendency in our society to overestimate the role of ambition, determination, and personality traits in accounting for these cases.

At a later point, I will discuss in detail this very entertaining book. Here I would simply like to point out that Gladwell commits one of the major inferential errors that I mentioned in blogging yesterday about Jerome Groopman’s How Doctors Think, namely the Confirmation Bias.

In every case of exceptional achievement that he treats, Gladwell cites exclusively evidence in support of his views. Nowhere does he mention instances that might raise doubt about his views or evidence that would limit their generality. Rather, he selects cases (almost always anecdotes) that conform to his claims. In this respect I find Outliers and almost everything else Gladwell has written quite misleading.

To mention briefly one example: In writing about the considerable advantage young Canadian hockey players have when they are born early in the year (they gain additional experience playing and practicing due the January 1st eligibility cutoff date for age-class hockey teams), he does not acknowledge that six of the thirty-three the players on the championship team he discusses were born in the later half of the year and, thus, are exceptions to the general claim he makes. How can their excellence in hockey be understood and would such an explanation provide an alternative account for the relationship Gladwell reports?

Recently someone asked me if in light of my concerns, I thought Outliers was worth reading. I really had to pause before answering. Yes, I said, it is surely worth it to Gladwell to write these kinds of books. And they are certainly very amusing and very well written. But unless a person approaches his works with a more critical eye, I would hesitate to recommend them.