We've looked at kids and sleep on Gifted Exchange a few times. Some gifted children seem to need less sleep than other kids (though this isn't a universal sign). But interestingly, there's some evidence that the usual sleep guidelines aren't necessarily right. Kids may need less sleep than the experts used to say.
An article in the Wall Street Journal this morning on "Challenging 100 Years of Sleep Guidelines for Children" notes that in 1897, a scientific book claimed 2-year-olds should be sleeping 16 (!) hours a day. Researchers in 2010 say that 2-year-olds should get 11.5 hours a night.
If you think about it, this makes the usual 2-year-old bedtime (like 7:30 p.m.) kind of nutty. If the kid is taking a 2-hour nap, this means it would be quite normal for the child to wake up at 5:30 a.m. Or earlier! My 2-year-old falls asleep around 9:30pm. He wakes up around 7-7:30 a.m. He takes a 2-hour nap. This adds up to exactly the right amount of time. It's just later. But why would I want to be up with him at 5 am? So I'm glad to know it's not worth fighting to get him down earlier.
My baby is shaping up to be a better night-time sleeper than the other two. She is usually asleep before 8pm and sleeps until 6:30-7am. She doesn't take great naps during the day - they tend to be short - which I was slightly worried about at first. But it turns out that the sleep guidelines for babies are 14-15 hours, plus or minus 2 hours. If my baby is sleeping close to 12 hours at night, she just doesn't need that much daytime sleep.
On one parenting list-serve I'm on, people use the abbreviation "YMMV" all the time. It took me a while to figure out that means "your mileage may vary." Meaning that what works perfectly fine for one kid won't work for another. Children, like adults, probably need varying amounts of sleep, and some kids are larks and some are night owls. I'm happy that at least my older two are now at the age where they can look at books in bed, which seems to keep them happy enough during the hours that other 4- and 2-year-olds are asleep.
How much sleep do your children get?