Freshly Baked Science
Should School Start Later?
24th January 2019
There it is again, that horrible sound signalling another day, your alarm is going off because it’s time to get ready for school. You roll out of bed, all groggy and still half asleep. How does this happen every time? You’ve tried going to bed earlier, but then you just lay in bed staring at the ceiling for a couple of hours. It’s just impossible to sleep early and wake up when you should for school.
I have good news for you, there’s nothing wrong with you! Many adults blame this strange sleep-pattern on lazy teenagers, bad habits, those damn phones, or video-games! The reality is quite different though, it’s not a habit nor anything you can choose. In a cruel bout of development, sleep rhythms change during our teens.
A whole mess of things happen during our teens, trust me, we’ve all been there. Hormones run rampant while “your body changes in new and surprising ways”. A lot of obvious changes tend to be discussed in health classes, but brains get forgotten. All those hormones mess up your head quite a bit, from rebellious and sensation-seeking behaviour to personality changes, and the star of this piece: sleep.
First off, sleep is important! It’s not a waste of time, it’s really important and keeps us functioning. Being asleep and being awake are actually two sides of the same coin, two states your brain can be in. Your body has a constant battle going on between sleep-promotion areas and wakefulness-promoting areas, a tug-of-war that shifts between each state during the day and night. When you are awake wakefulness-promoting areas slowly lose their grip on the rope until eventually, you fall asleep, upon which they start tightening their grip and the sleep-promotion areas start loosening up.
A big player in this tug-of-war is a small brain area called the Suprachiasmatic Nucleus (SCN) which controls a 24-hour circadian rhythm. It’s a bit of a weird player though, it likes to change teams. During the day it switches teams and starts tugging on the other side. The rhythm is set up in such a way that you are most awake during the day and closest to sleep during the night.
For reasons we still not fully understand, hormonal changes affect the rhythm in adolescents causing it to shift. This means the natural sleep-wake cycles of adults no longer apply. The new rhythm causes teenagers to stay up later and sleep longer in the morning. It also causes more sleepiness in the morning when waking up. It’s like a biological jet-lag that cannot be forced back by going to bed early.
The culprit is melatonin, a hormone that makes you sleepy and is released when it’s dark. You might have heard of it being sold as sleeping medicine. The mechanism is pretty straightforward: it gets dark outside, the body releases melatonin, you get sleepy so you go to bed. In the morning the light triggers a decrease, allowing you to wake up naturally. Now comes the kicker though, during our teens the melatonin response is delayed. Night-time comes, but melatonin isn’t being released, so no sleepiness. The body still needs 8-10 hours of sleep during adolescence, so when you finally do go to sleep you’ll sleep until later in the morning.
A study was done to see what was going on, and they found that there is an increase in light sensitivity during adolescence. This increase means that when night-time comes it takes longer for the body to deem it “dark enough” to start releasing melatonin. You physically don’t feel the need to sleep until much later because of it. Eventually, the hormone storm dies down again (it will, I promise) and the regular adult rhythm takes over.
This still leaves us with a problem. The world is built for adult sleep-patterns. School, sports, work, all start in the morning and ends in the late afternoon. The adult-rhythm clashes with the teenage-rhythm. It has nothing to do with being lazy or bad habits, it’s yet another biology thing making life that little bit harder.
What does help is starting school a bit later. A district in Seattle shifted the entire school-day by one hour, starting later in the morning to better match student sleep-cycles. Guess what? It worked out pretty well. Attendance improved, there were less car accidents, and grades improved. Teenage life is tough enough as it is, a small change can make a lot of difference.