The article about Dan McLaughlin’s quest to go from zero-to-PGA Tour through 10,000 hours of deliberate practice got linked around a bunch yesterday. Several people who pointed to it made a typical mistake. Malcolm Gladwell wrote about the 10,000 hours theory in his book, he did not come up with it. It is not “Gladwell’s theory” and McLaughlin is not “testing Gladwell”. The 10,000 hours theory was developed and popularized by Dr. Anders Ericsson (here for instance) — who you may have heard of from this Freakonomics piece in the NY Times Magazine — before it became a pop culture tidbit by Gladwell’s inclusion of Ericsson’s work in Outliers.