Let Teenagers Sleep In
One of the many fascinating facts I learnt from Matthew Walker's "Why We Sleep" is that the biorhythms of teenagers are shifted to later hours compared to those of adults in all human cultures of the globe, even in those rare societies hardly affected by technology. In evolution this was likely beneficial to make it easier for teenagers to socialize among themselves without adult disturbance, which was necessary to drive their tribe out of its ruts, to pioneer innovation and adaptation to changed conditions. In modern society we are stupid to undermine this by depriving the upcoming generation of their sleep.