The Greek god Hypnos, the personification of sleep, lived in a cave around which the river Lethe (river of forgetfulness) flowed. Symbolic of the border between Hades and the paradise of Elysium, the river induced forgetfulness when drank by the ‘shades of the dead’ and cleaved them from their earthly lives. It’s interesting that the Greeks found congruence between sleep and memory as far back as c.2500 years ago, the personification of Hypnos and the river Lethe suggesting the ‘sleep world’ synonymous with forgetting. To modern educators, it seems cognitive science is beginning to affirm this classical insight into the relationship between rest and memory.
When my form group arrives each morning, it’s clear who’s sojourned in the snoozy world of Hypnos and… who hasn’t. A handful of the boys return my greetings. The majority, however, the ‘shades of the dead’, still fight the pull of their own sleepy caves, Hypnos on their shoulder ushering them back to shaded slumber in their underworlds. Irrespective of who’s sleepy and who’s not, the boys have a full timetable to tackle, so they best just tie up their eyelids and get on with it.
But what does the science say?
It’s clear teenagers are fighting sleep deprivation. Research suggests three out of four children have difficulty getting to sleep, and this correlates with my experiences at school. It’s also clear, although not frequently discussed, that teenagers must fit into ‘our’ daily structures – the adults’ timetables which are absorbed into the rhythms of every school day. Thus, teenagers’ sleep needs take second place to the timing of the school day, which of course is designed by us and, ironically, ‘for’ them. Research shows, however, that teenagers need more sleep than adults, more slumber in the snoozy cave of Hypnos. But why?
This has a lot to do with the body’s ‘circadian rhythm’ – essentially, the body’s 24-hour clock that regulates physical, mental and behavioural changes – including sleep. Melatonin, the hormone released by the body to aid sleep, is generally released at the same time each evening in adults. However, the release of melatonin is delayed in teenagers by between one and two hours, so when we adults are greeting our own ‘Hypnos’, the teenagers in the house are still in a lucid state of wakefulness. Sound familiar?
Research also shows adults have virtually no melatonin in their brains when they wake; teenagers, by contrast, still have melatonin swishing through their brains come morning. It stands to reason they may appear disengaged with their ‘earthly lives’ because they are still scrambling out of their ‘caves’. It would also seem that the release of melatonin is further delayed by artificial light: room lighting, iPads and, of course, mobile phones. However, teenagers’ predilections for all things technological cannot be to blame entirely, as it seems teenagers are predisposed to be awake for longer and to need more sleep than adults and, therefore, to crawl out of their pits in the morning later than adults.
But how does this impact education?
There are various reasons why sleep is important for healthy mental and physical function. In the context of secondary education, two reasons are immediately apparent. Firstly, sleep promotes the release of growth hormones, so if the body doesn’t get enough sleep, these growth hormones are suppressed, resulting in difficulties with reading, spelling and arithmetic. Secondly, and perhaps most significant for learning, sleep allows our brains to release glial cells, which clear up all the waste material from the day’s activities. Glial cells combine with other systems in the brain to carry out this maintenance, and considering the constant stimuli of daily experience, then it is no wonder our brains need to ‘clean up’ the input. Significantly, teenagers must get the sleep they need if their glial cells are to prep the workspace for the next day; teenagers with sleep deprivation will struggle the next day at school, and the implications for their learning go without saying.
But it’s not all bad news.
This research also suggests that the later a learner revises in the day, the more the information will stick – and not be at the behest of our glial cells. Common sense says there are fewer distractions in the evening, so the brain doesn’t have to sift through all the waste matter dumped on top of learning that would be the case if revision was done in the morning.
But how can schools implement this research to facilitate teenagers’ sleepy dispositions? After all, mobile phones and screen time aside, teenagers have little control. It’s up to us as teachers, surely, to help them.
Teenagers often feel a sense of injustice with the structure of the school day. Furthermore, this injustice is compounded when teachers wave the ‘school policy’ at them and accost them for lateness, distractedness, not concentrating or failure to complete work in a given time. Add in a crammed form-time schedule, with little opportunity to ‘wake up’ and prepare – mindfully – for the school day, then you have a recipe for the stereotypical teenage reticence.
And who can blame them? Well, teachers blame them, daily. This dissonance between school and the science of cognitive development only serves to cleave a culture of ‘us versus them’. We, as teachers (and parents), need to appreciate that teenagers’ brains do not respond to the world in the same way that our brains do; we need to make concessions for this; and we need to be honest with schools, and with our own practice, when the timetable (and ‘policy’) subjugates children and fails to ‘fit’ within – and work for – the teenage brain.
So, why do their young minds tire later?
Clinical psychologist Dr John Coleman – author of The Teacher and the Teenage Brain, from which I am indebted to for the ‘science’ within this article – considers two reasons for this phenomenon:
One is the theory that when humans were still nomadic, it was important for someone to keep watch in case of predators. Therefore, this role was given “to the younger members who were just reaching adulthood. The longer [teenagers] could stay awake, the better for the tribe. Thus, melatonin release gradually altered to help those keeping watch to avoid sleep for longer into the night.”
Two is concerned with the ‘social circumstances’ of teenage development. If young people are to grow into independence, they need time away from their adult carers. Thus, staying awake longer at night allows them to “pursue their own activities, no longer being monitored by the adults in the family.”
Both fascinating explanations.
Teenagers are too often viewed as empty vessels who sail up to our lessons primed, ready and waiting for us to pour in all of our subject knowledge, when in truth they are battling the curse of adolescents and the mutated traditions of authoritarian environments. We squeeze children into school ‘models’ with the expectation – and hope – they conform as if by osmosis. Yet, their vessels are pretty full by the time they sail up their own river Lethe, some of whom will be only just treading water, and some near drowning in the currents of sleep deprivation. We need a fresh perspective on timetabling in secondary education, and it’s only right that this ‘perspective’ coalesces with the cognitive needs of children, grounded in the science of teenage development. We must follow ‘their’ timetables, and surely a failure to respond to the research is, at best, supine.