Sleeping late is a biological questions

Good news for teens who do not wake up to 3 or 4 in the afternoon: his stuff is not laziness, but a biological need. Work done by biologists at the University of Siena in Italy showed that this custom is the result of a process of "setting the time of the internal biological clock" that, influenced by the hormone melatonin-substance in the brain that regulates rhythms sueño/vigilia- is "ahead" to get in tune with the times of the hormonal cycles of maturity.

During this adjustment, the melatonin increase its concentration in blood over time, leading to sleep until the afternoon. Similarly justifies the stamina of teenagers off the haggard: Scientists found that during adolescence the concentration of melatonin, inducing sleep, down to a minimum after midnight.