Sleep is good. We all need sleep. It is very rare to hear someone complain about getting too much of the stuff (unless they are diabetic). As the parent of a toddler who has thus far failed to grasp the concept of staying in bed past 6am, I am regularly bemoaning the shortfall of shut-eye in my life. But insufficient sleep can be quite a serious problem, and not just for parents of young children.
A Wall Street Journal article has highlighted the potential move in the US to introduce later school start times for adolescents. While it may be a cliche for people to mock and laugh at teenagers for being lazy with their constant sleeping and lethargy, it’s actually not something they can control, and there’s strong evidence to suggest that the need for more sleep at atypical times is a consequence of puberty.
Your typical teenager doesn’t just become lazy and irritable due to attitude problems; their brains and bodies are changing, meaning they need more sleep than usual, and at different times. One of the effects of puberty is it makes the individual get tired and need sleep later than “normal” (eg falling asleep after midnight rather than 10pm), but the school schedule requires early rising regardless of bed time. Coupled with the fact that on average teenagers need more sleep than people of other ages, this is a recipe for inevitable sleep deprivation, resulting in poor concentration, lethargy, behavioural problems, and much more.
Mixing up your sleep schedule with the external environment can be very disorientating, as anyone who’s ever had jet lag will know. When you consider that teenagers are also people being given access to cars and alcohol for the first time, this is not the best time for them to be constantly exhausted. Ergo, there is a real push to make the school day start later for adolescents, to limit the disruption and mental health problems caused by this sleep cycle/academic schedule misalignment.
The notion of structuring schedules around sleep requirements may seem like a great idea. Imagine if your work started whenever you woke up, rather than you having to wake up because you had to go to work. As long as everything gets done, everybody wins, surely? Unfortunately, it’s not quite that simple.
We know that babies/toddlers and teenagers need more sleep than is typical, possibly for similar reasons; the baby/toddler brain is still being formed, whereas during adolescence the teenage brain is basically reconfiguring for efficiency, pruning all the needless connections obtained during childhood, suggesting that intense brain development needs more sleep. But even this is uncertain, and that’s the main concern; overall, we don’t really know what sleep is for, and why we need it.
It might seem obvious: we need sleep to rest. But when asleep, we only use 5-10% less energy than when awake, which isn’t exactly a total shutdown of the body. And the brain remains almost as active during sleep, just in ways we experience differently. Much of the proposed purpose of sleep focuses on brain management and processing, but it’s still uncertain as to precisely what it’s for.
On top of this, despite the assumption that sleep follows the day-night pattern, many people don’t conform to this pattern. Even without genuine physical causes for disruptions, people sleep at different times for other reasons: daytime siestas in hot countries, night-shifts resulting in daytime sleeping, and so on. Plus, exactly how much sleep individual adults need varies considerably.
We may know that adolescents need more sleep at different times, but overall that’s pretty much all we know for certain about sleep. And until we know more, it would be unwise to extend legislation based on sleeping behaviour to the general population.
