New York Times:
Efforts to improve educational outcomes through extending the school day may have unintended and counterproductive consequences if longer days are implemented by moving the school bell earlier or by pushing more homework later into the night. Young children are biologically primed for “early to bed and early to rise,” but as children pass through middle school and into high school, biological processes keep them up later.
Even without a move to longer school days, many adolescents are already in trouble because they get too little sleep; their biological propensity to stay up combines with other factors, like parents who have largely ceded responsibility for setting bedtimes and the pernicious, sleep-defeating influence of distracting technology in their bedrooms.
Read the whole story: New York Times