Bora Zivkovic compiles some information on how kids circadian rhythms change during adolescence, and advocates for later school starting hours.
He points out the interesting concept of chronotypes:
Everyone, from little children, through teens and young adults to elderly, belongs to one of the ‘chronotypes’. You can be a more or less extreme lark (phase-advanced, tend to wake up and fall asleep early), a more or less extreme owl (phase-delayed, tend to wake up and fall asleep late). You can be something in between – some kind of “median” (I don’t want to call this normal, because the whole spectrum is normal) chronotype.
And how your chronotype gets phase-delayed at puberty:
No matter where you are on these continua, once you hit puberty your clock will phase-delay. If you were an owl to begin with, you will become a more extreme owl for about a dozen years. If you are an extreme lark, you’ll be a less extreme lark. In the late 20s, your clock will gradually go back to your baseline chronotype and retain it for the rest of your life.
Sleep patterns change during adolescence, but unless you can alter the school day, students need to figure out ways to deal with their predilection for going to bed and waking up late. Jason at FrugalDad has a nice compilation of statistics about why we need sleep. Particularly useful is the section on different ways to get more sleep. (I also like the fact that he cites his sources at the bottom.)
Uncomfortable sleeping arrangements of the (simulated) slum.
One of the highlights of the Heifer Ranch trip was the chance for students to spend a night in their global village. It’s really a set of villages, each simulating a life in an under-developed part of a different developing country.
The Thai village. Everyone wanted to end up in the Thai village.
The Guatemalan house is pretty nice; it keeps you out of the elements, you have actual beds, and running water. The Thai houses are actually pretty awesome. They stand on stilts next to the open fields, giving good air circulation and elegant views. They remind me a lot of some of the older houses from where I grew up. The refugee camp, on the other hand is pretty decrepit. The slums aren’t much better but at least have one house with a wooden floor, though the door was so broken it was pretty useless.
Our students were assigned villages at random, but varying numbers were placed in each village to replicate the population densities more accurately. One adult was assigned to each village. We were supposed to act as if we were incompetent (not hard I know), either as two-year-olds or senile elders.
I ended up in the high population slums.
A dragonfly sits on the hard ground in the slums.
On the positive side, I was not the only adult there. Mrs H., who had joined our group with her daughter for the week of activities at Heifer, was also assigned to the slums. On the negative side, she and the girls commandeered the one “posh” building that had an actual floor to sleep on. The boys and I had to sleep on the hard, stony ground.
It didn’t help that one of the boys was “pregnant”. One person in each group been given a water balloon in a sling and told to keep it with them, safe, until dinner, when they would “give birth”, at which point the others in the “family” could help take care of the “child”. A key objective was for the child to survive until morning.
The boys scouted all the houses in the village and scavenged a large piece of metal grating to sleep on. It was not great, but it was doable. Better, at least, than the concrete-hard, uneven ground.
Making dinner over an open fire in the simulated slum.
There was a lot more that happened on that night. None of the groups was given enough to be comfortable on their own. There was a lot of haggling, trading and even commando raids, but, in the end, they pulled together and made something of it.
The experience was quite useful, I think. Conditions were uncomfortable enough to register with the students, though a single night is not enough to really internalize all the challenges of urban slums where over one billion people spend their lives. But it does provide some very useful context for the poignant images of Jonas Bendiksen (Living in the Slums) and James Mollison (Where Children Sleep).
Image from the book, Where Children Sleep by James Mollison.
Even without the text descriptions, the pictures are wonderfully composed and evocative. I think I’m going to have to add this one to our library.
An interesting project would be to have my students take their own pictures of their rooms. Just in the book, some of the contrasts are quite startling.
The study was presented at the annual Pediatric Academic Societies meeting under the title Is Sleep Related to Obesity in Young Adolescents?. Interestingly enough, there was less of a correlation for girls.
However, in girls, sleep duration was not related to any of the weight-related variables with the exception of less sleep on weekends being related to BMI. – Lytle, Pasch and Farbaksh, 2010.
The USDA has a nice page that touches on the research that’s looking for specific links between sleep deprivation and weight. Their take is that kids don’t get out enough because increased opportunities for indoor entertainment don’t require much activity and disrupt sleep cycles. They suggest that fat cells themselves may respond to changing circadian rhythms.
Abnormal sleep/wake patterns may change circadian clocks that normally allow cells to anticipate variations in the outside environment, such as changing levels of nutrients (glucose, fatty acids and triglycerides) and hormones such as insulin. – Flores, 2007.
The mind tend to wander when working at repetitive tasks that don’t require much brain processing. So the brain just switches over to thinking about long-term things. There is even a specific part of the brain, called the “default network” that starts up when we zone-out. That, at least, is what I summarize from looking at some neuroscience research by Malia Mason and others (2007) on wandering minds.
What’s interesting is that the default network tends to be used for “certain kinds of self-referential thinking, such as reflecting on personal experiences or picturing yourself in the future” (Zimmer, 2010). That means introspection. Introspection is the point of Personal World, so it follows that we should want our students’ minds to wander during Personal World.
So how do we design the Personal World time and environment to encourage daydreaming? Repetitive tasks aid mind-wandering, as will anything that is rote that does not require acute cognitive focus. Raking the garden, doodling should be encouraged, in fact, anything that encourages boredom.
I would think also, that reducing the cognitive load would also be beneficial, which might also mean no music. Yet music helps isolate the individual, particularly when they’re using ear buds. Perhaps quiet, “boring” sounds would be best, coming a shared radio so students can’t choose to listen to something else. Of course, if you’re listening to the music on your mp3 player then you tend to tune out the songs anyway so maybe it all falls out in the wash.
Of course this could all be malarkey, based as it is on a single study, so I’ll end with the words of caution that coms at the end of the article:
Although the thoughts the mind produces when wandering are at times useful, such instances do not prove that that the mind wanders because these thoughts are adaptive; on the contrary the mind may wander simply because it can. – Mason et al., 2007.
Focused work. We like to see our students focused on their work and we give them long blocks of time to do so. It is hard, however, for anyone to stay on task for two hours straight. You have to allow for a certain amount of mind wandering and daydreaming. What a lot of neurologic research is uncovering is that zoning-out is an essential part of putting the pieces together and helps with learning.
When we are no longer even aware that our minds are wandering, we may be able to think most deeply about the big picture. – Zimmer (2010)
Sleep rhythms change during adolescence. Students often find it harder to get to sleep at night and harder to get up in the morning. Their best time for learning is in the afternoon. So why not just adjust the school day? Margaret Ryan has an interesting article on the BBC website about an English secondary school that did just that, starting lessons one hour later at 10:00am. Their preliminary results seem favorable, but the research has not yet been published.
Prof Till Roenneberg, who is an expert on studying sleep, said it was “nonsense” to start the school day early.
He said: “It is about the way our biological clock settles into light and dark cycles. This clearly becomes later and later in adolescence.”
Prof Roenneberg said if teenagers are woken up too early they miss out on the most essential part of their sleep.
“Sleep is essential to consolidate what you learn,” he said.
