Gladwell's argument wrt precociousness is totally disingenuous and not even logical. He cherry picks examples that seemingly verify his populist positions, and then draws conclusions that are in direct contradiction to the minimal evidence he cites.
First Argument paraphrased: I was a precocious young runner and an average adult runner. Dan Consiglio was a non-precocious and average young runner, but a great adult runner. Therefore precociousness does not predict whether one will become a great runner.
Second Argument: “In singling out people like me at age 13 for special treatment, we discouraged other kids from ever taking up running at all. And we will never know how many kids who might have been great milers had they been encouraged and not discouraged from joining running, might have ended up as being very successful 10 years down the road.”
How does the evidence Gladwell presents in his first argument even begin to support his second argument? He has just explained that Consiglio ended up great despite no special attention, and that he ended up average with special attention. Now we are to believe that special attention==great adult runner and no special attention==discouragement and leaving the sport? What if encouragement causes complacency and discouragement causes runners to work harder to prove themselves?
Unfortunately this sort of illogic is par for the course with Gladwell, but people will continue to buy his books to convince themselves that there is no such thing as innate ability, and that the only thing separating them from greatness is 10,000 hours.