Top sociologist Malcolm Gladwell knows the recipe for success: 10,000 hours of practice.

The Beatles racked up their 10,000 hours performing five hours a night, seven nights a week at a German strip club. Bill Gates racked up his 10,000 hours at the University of Washington medical center, between 3 a.m. and 6 a.m.—the only time the computer terminal was free. Even Mozart, the quintessential “natural genius,” racked up 10,000 hours before he turned 21; his father had him arranging concertos when he was six.

Gladwell got the 10,000-hours rule from psychologist K. Anders Ericsson. In the early 1990s, Ericsson divided violin students at Berlin’s Academy of Music into three groups—virtuoso, good and decent—and he questioned the members of each group about their practice habits. Students from all three groups began practicing at age four or five, for a couple of hours each week. But by age 14, the students in the virtuoso group were practicing 16 hours per week, more than twice as much as their decent counterparts. By age 20, the decent students had tallied 4,000 hours of practice, the good students 8,000 and the virtuosos 10,000.

“The striking thing about Ericsson’s study,” Gladwell writes, “is that he and his colleagues couldn’t find any ‘naturals,’ musicians who floated effortlessly to the top while practicing a fraction of the time their peers did. Nor could they find any ‘grinds,’ people who worked harder than everyone else, yet just didn’t have what it takes to break the top ranks.”

In his new book Outliers: The Story of Success, Gladwell co-opts Ericsson’s 10,000-hours rule to introduce his thesis, that success is the product of opportunity, not innate talent or general intelligence. “Once somebody has reached an IQ of somewhere around 120,” Gladwell writes, “having additional IQ points doesn’t seem to translate into any measurable real-world advantage.”

Gladwell’s egalitarian message, that anybody can succeed if given the opportunity, brings up a not-so-egalitarian reality: Not every kid has the opportunity to practice the violin, compose concertos or program computers for 10,000 hours. For many children, that sort of free time is a luxury.

The main flaw in Outliers is Gladwell’s failure to investigate which factors cause some children to pursue their passions for 10,000 hours and which cause others to give up after, say, 20. I suspect the biggest factor is progress. I suspect the students who make it to 10,000 are the ones who show progress early on. Progress, after all, is a powerful motivator. I was most motivated to practice the piano when my teacher, Mike, told me I was “really coming along” and when my fingers seemed to find the keys on their own.

Because Gladwell fails to bring up the issue of progress, he also fails to investigate why some people progress faster than others.

Perhaps “natural talent” does play a role. Perhaps Gladwell has his causal chain backward (i.e., some children practice 10,000 hours because they enjoy practicing; they enjoy practicing because they progress quickly; they progress quickly because they have natural talent).

Before Outliers is through, Gladwell reveals why he thinks Koreans crash so many airplanes, why Chinese children are better than their American counterparts at math, why so many top New York lawyers are Jewish, and why people with earlier birthdays (i.e., January, February) make the best hockey players. The answers might surprise—especially the one about Chinese kids and math.

Gladwell concludes the book with a handful of practical recommendations that the Department of Education would be foolish to ignore. The man has some smart ideas. But Gladwell doesn’t overwhelm the reader with his smartness; he lets readers connect the dots for themselves. When you read Gladwell, you not only recognize the man’s intelligence, but you also feel intelligent yourself.

I don’t know how Gladwell writes like this, but I’m guessing he’s had over 10,000 hours of practice.