eople with higher IQs are more apt to be nocturnal night-owls. Those with lower IQs tend to restrict their activities primarily to daytime.
I wonder if the correlation between high IQ and going to bed late is also due to smarter people often being perfectionistic and having too much they are trying to finish before going to bed?
Smart people SLEEP LATE - Winnipeg Free Press
And a few fun facts about sleeping in the animal kingdom: Sleep parameters vary among animals. Cows, for instance, sleep open-eyed. Horses sleep standing up. Some birds can sleep in flight, others while standing. Dolphins sleep in one-half of their brain while the other half remains awake. Bats need 19.9 hours of sleep every 24 hours, lions need 13.5, rats 13, cats 12.5, whales 5.3, deer 3.1, giraffes 1.9, most birds three to eight and donkeys three.