> Seems like a bit of a tail wagging the dog situation. How do we know the more relaxed/organized schedule leads to success, and not that success leads to a more relaxed/organized schedule?
That's a facile rhetorical question. You could similarly ask, "How do we know that good food and exercise lead to healthy human beings, rather than that already-healthy human beings have access to good food and exercise?" The answer, of course, would be research. All the students were working the same amount. Their work habits were different.
Furthermore, although I can understand why success might lead to more relaxation (for instance, by making students feel less stressed about their future prospects), I don't see how it would lead to more discipline or a focus on deliberate practice. Successful people tend to do the same things they've always done, for the obvious reason that they are successful doing it. If they were undisciplined and successful, what motivation would they have for becoming disciplined?
In addition to the data and the research (and Newport has illuminated many more results than this one), two anecdotes come to mind. The first is from The Effective Executive by Peter Drucker, where he brings forward some examples:
> [Consider] Harry Hopkins, President Roosevelt’s confidential adviser in World War II. A dying, indeed almost a dead man for whom every step was torment, he could only work a few hours every other day or so. This forced him to cut out everything but truly vital matters. He did not lose effectiveness thereby; on the contrary, he became, as Churchill called him once, “Lord Heart of the Matter” and accomplished more than anyone else in wartime Washington.
The second is from my personal life. Having children forced me to concentrate my efforts and create a much more disciplined work life. I'm more successful and focused than ever. Although this is just an anecdote, this phenomenon is commonly reported by other people in demanding technical or executive roles.