Dr. Kelley said that, when children are around ten, their natural wake-up time is about 6.30am; at 16, this rises to 8am; and, at 18, a person’s natural waking hour is 9am, although you may think they are just a lazy teenager. The normal school starting time works for 10-year-olds but not for 16- to 18-year-olds. For the older teenagers, it might be better to start the school day at 11am or even later. “A 7am wake-up time for older teenagers,” says Kelley, “is the same as a 4.30am start for a teacher in their 50s.”
What does Kelly say about the wake-up time of 18-year-olds?
It is naturally around 9am It depends on how lazy they are It is similar to the natural waking time of teachers It naturally varies over the course of the week