Here's a short video from the brilliant folks at ASAPScience that highlights some of the differences between morning larks and night owls. Anthropologists theorize that delayed sleeping developed out of evolutionary necessity. In humans' early days, a person in the tribe was needed to stay up overnight to protect it against predators and keep the fire going, so to speak.
Although it sounds a bit far fetched, this theory is plausible to me. As a chronic delayed sleeper, I have long suspected I simply was wired differently from the majority and that's why I barely can function before 11 am and feel my best in the evening. You can't fight nature. Believe me, I've tried.
