Why do teenagers sleep late?

One of the main theories for this phenomenon is that during adolescence melatonin - a hormone that regulates the sleep cycle - going to be released later, around 21 hours, and not in the early evening, as with children. This causes many people have difficulty falling asleep before 23 hours. As this stage of life the average period of sleep is nine hours, sleeping more adolescents outweigh the morning. Another theory on the subject further afield sociological she said, young people wake up later as a result of a profound change in habits in early life.