Strange how things change. I naturally wake at around 6am these days, and enjoy getting into work early for an hour or so of quiet work before the hurly-burly begins.
But I can still just about remember my teenage years, when dragging myself from sleep and through the motions of getting dressed in time for the 8am bus was a miserable struggle with a head full of fuzz. Then, come the weekend, I’d pull the duvet over my head until midday at the earliest, no matter how sunny and bright the day, much to the disgust of my parents.
I was fascinated to learn that the teen shift to night-time waking and day-time sleeping has a physiological basis. Natural sleep onset shifts by about 2 hours, compared with ‘middle’ childhood, so that the onset of puberty means children who previously got sleepy at 8pm or 9pm can’t even think about sleep until 11pm. However, they still need around 9 hours of sleep, hence the difficulty with waking at 6 or 7am.
But long-term lack of sleep causes more than grumpiness in teenagers. There’s a growing body of research showing that lack of sleep links with health conditions like obesity and depression. And if our 15-year-olds are all dozing through class, what effect does that have on their learning?
So the story I wrote last week, about shifting school start times forward by half an hour, added to a growing heap of evidence. After 3 months of the later start time (8.30 compared to 8am), the adolescents taking part were happier, less likely to fall asleep in class, felt more energetic and were more likely to take part in after-school activities.
The study wasn’t perfect. It didn’t monitor school achievement, for example, and indeed there’s little consistent evidence that later school hours has any effect on grades. Also, there’s a limit to how much you can generalise to the majority of schoolkids, from a study of rich white children at a private Rhode Island boarding school.
But of all the things that feed into how we set school hours – parental convenience, road congestion, tradition – surely children’s health and happiness should be somewhere on the list?