A new paper out in Intelligence, from a group of authors led by David Hambrick, is getting a lot of press coverage for having “debunked” the 10,000-hour rule discussed in Malcolm Gladwell’s book Outliers. The 10,000-hour rule is — well, actually, that’s the point of this post: Just what, exactly, is the 10,000-hour rule?

The debate in Intelligence is between Hambrick et al. and researcher K. Anders Ericsson, who studies deliberate practice and expert performance (and wrote a rejoinder to Hambrick et al. in the journal). But Malcolm Gladwell interpreted Ericsson’s work in a popular book and popularized the phrase “the 10,000-hour rule.” And most of the press coverage mentions Gladwell.

Moreover, Gladwell has been the subject of a lot of discussionlately about how he interprets research and presents his conclusions. The 10,000-hour rule has become a runaway meme — there’s even a Macklemore song about it. And if you google…