We need a wake-up call when it comes to adolescent sleep

THIS year marks the 30th anniversary of a study that sparked a global movement to change the timing of children’s school days. Published in the journal Sleep by Mary Carskadon at Brown University, Rhode Island, and her colleagues, this paper set out to answer an age-old riddle: why do teenagers stay up so late, and why is it so hard to pry them out of bed in the morning?

Conventional wisdom held that teens’ preference for waking up and staying up later was driven by social forces – the pressures of school, the pleasures of partying. Carskadon, however, suspected that …