Although I wake up for work every day and live the early bird schedule, I am a night owl. Every so often my body will reject the schedule and I wake up between midnight and 1:00AM. Of course I am sleepy by sunrise but I have to push through the day to get back on schedule.
Yeah sure, this happens to me as well. I just woke up at 3:30 today, squeezed a few oranges and played the guitar for an hour like it was the middle of the day.
And if for some reason I'm home alone for more than a couple of few days I'll revert to my schedule of sleeping early in the morning.
But my point still stands, I can adhere to my new schedule pretty effortlessly when the situation is right.
Which makes me personally question how much of being a night person is nurture.
Most of the night persons I've encountered have a pretty consistent schedule of staying up at night, which isn't what should be happening if they fit the profile of the kind of person that the linked study examines.
A person like that should have, when situations allow, no schedule because they function on a non-24-hour cycle.
