[jwilliams]

If you’re able, you should do what comes naturally

Not sure I agree with this - For me, sleeping is just a habit. I get into the habit of staying up late, or the habit of getting up early.

This makes it sound trivial - but it's not - habits take work to form and work to change.

Naturally everyone is different. I'm sure there is research that disagrees with me :-) But that's my experience anyway.

[ciupicri]

You might find this interesting: http://en.wikipedia.org/wiki/Delayed_sleep_phase_syndrome

[jwilliams]

Absolutely. e.g. I know there is a lot of research around teenagers having distinct sleep patterns/requirements.

I guess my point was - don't necessarily pigeon-hole yourself as a "night owl" or "morning person".