In his 2008 book, Outliers: The Story of Success, Malcolm Gladwell culled a memorable and marketable tip from a 1993 study of violinists at a music academy in Berlin. The study’s authors, he said, found that the most talented and accomplished 20-year-old violinists at the school had practiced an average of 10,000 hours. Ta-da! Right? Not quite. It seems that Gladwell didn’t really understand what he was talking about.


In an adapted excerpt from their new book, Peak: Secrets from the New Science of Expertise, Andres Ericsson (one of the authors of the original study, The Role of Deliberate Practice in the Acquisition of Expert Performance) and Robert Pool detail the ways in which that iconic stat by Gladwell misrepresented the original research.

Here’s the thing—it is fairly intuitive that practice will make someone better at what they’re practicing, if not perfect at it. So in the case of the violins: more practice = better performance. Since you don’t need Gladwell to tell you that, the crux of his 10,000-hour rule is that there is a specifically meaningful cutoff line—that this number reflects the minimum hours spent “practicing” before achieving a degree of mastery. Gladwell claims to have calculated roughly 10,000 hours of “practice” done by The Beatles, as well as Bill Gates before they were able to become rich and famous off their talents.


Some of this was already disproven a few years ago. A 2014 Princeton meta-analysis of 88 existing studies about how practice affects ability in all different fields found that, actually, the correlation was quite low and varied. Practice is more important in music (responsible for 21% of variance) than sports (18%), more important in sports than education (4%), and barely at all impactful in the broad scope of “professions” (just 1%).

Gladwell himself acknowledged a version of this that same year during a Reddit AMA in which he clarified, “There is a lot of confusion about the 10,000 rule that I talk about in Outliers. It doesn’t apply to sports. And practice isn’t a SUFFICIENT condition for success.”

Sports are a good example of how other factors (like, genetics) might come into play when determining a particular person’s success. But Ericsson and Pool claim that even when practice is more influential, there’s nothing distinct about the 10,000 hour mark.


First, there is nothing special or magical about ten thousand hours. Gladwell could just as easily have mentioned the average amount of time the best violin students had practiced by the time they were eighteen — approximately seventy-four hundred hours — but he chose to refer to the total practice time they had accumulated by the time they were twenty, because it was a nice round number. And, either way, at eighteen or twenty, these students were nowhere near masters of the violin.

Basically, Gladwell cherry-picked the nice round number and worked backwards to show that 20-year-old violinists had practiced on average that long—on average.


Second, the number of ten thousand hours at age twenty for the best violinists was only an average. Half of the ten violinists in that group hadn’t actually accumulated ten thousand hours at that age. Gladwell misunderstood this fact and incorrectly claimed that all the violinists in that group had accumulated over ten thousand hours.

Ten thousand hours isn’t any sort of baseline, especially when you expand beyond this particular study.

Although Gladwell uses The Beatles to bolster his rule, Ericsson and Pool also cite a 2013 biography of the band that casts doubt on those calculations. In his book Tune In, Mark Lewisohn shows that The Beatles became famous long before they had performed for that many hours (the basis of Gladwell’s evidence) but also argues that their song writing was largely responsible for their stardom, something Gladwell fails to incorporate into his hour-tallies.


None of this diminishes the spirt of the advice. As Ericsson and Pool write, “If you practice something for a few hundred hours, you will almost certainly see great improvement.” The value in dismantling Gladwell’s adage is less about dissuading dedicated practice and more about remaining skeptical about arbitrary rules for success. If you want to improve at something, by all means, practice for 10,000 hours. But then, if you haven’t mastered it, go ahead and keep practicing.