The impact of school shutdown on sleep in adolescents: a natural experiment

Agreed with all points. I often find that these sorts of observational studies with weak methods that provide evidence for something the unblinded study participants would want to support (e.g., this study, observational studies of the effect of reduced workweek hours on productivity, many of the observational basic income studies) are really hard to evaluate fairly. It becomes easy to latch onto the conclusions when the intervention is one you're predisposed to believe in and to latch onto the methodological weaknesses when it's one you start of opposed towards, and so I feel like they don't really advance science forward at all.

It's the old qualitative vs quantitative debate.

Interviewing 45 people can provide much more meaningful information than sending a survey to 1000 people. I'm not saying it's the case there, I'm not an expert in this domain. But 45 semi structured phones interviews is perfectly fine for a lot of research.

Anecdotal evidence, but in my school the afternoon shift was associated with more "problematic" behaviour, both boys and girls. More rough and tumble play, that is the technical term I think, more abuse and fighting. Might have something to do with all those mornings without parental supervision.

> As for “natural sleep cycle” and “improved quality” I can tell you that this is self-made (or rather parent-made) problem in this case. If I take my children’s devices away at 8pm, then they go to bed by themselves after 9, have a good sleep and ready for school.

When talking about adolescents, which this study does, this is false since in adolescents the sleep phase is biologically delayed.

lived in USSR till 1993 and never heard about two shift schools...

interesting

> If I take my children’s devices away at 8pm, then they go to bed by themselves after 9, have a good sleep and ready for school.

You have forgotten to mention the age of your children.

(Noting that there is a change in circadian rhythm - around 20:30 up until puberty, and then much later - 23:00 or so for late teens - and then later it shifts back earlier. This is fairly well understood and agreed science. So for children under 13 or 14, you'd expect comparable sleep patterns to adults - but for that 15-20 range, not so much.)

> Ironically, similar thing happens to me, but sadly there is nobody to take away my phone, as time of this comment shows.

You sent this at about 1330 Moscow time.

I think the simple answer is just that children need more sleep than adults. It’s not just about a different schedule. The National Sleep Foundation recommends[1] 9-11 hours for school-aged children and 8-10 for teenagers.

[1] https://www.sleephealthjournal.org/article/S2352-7218(15)000...

Actually your speculation is a good one.

From the book Why we sleep, by Matthew Walker, it's reported that teenager's circadian rhythm is different from the one of their younger siblings. It's shifted progressively forward, so forward that it passes even the timing of adults.

This is something wired in their brain and should be addressed when setting school times.

Moreover, Walker also proposes a socio-evolutionary explanation of why adolescent sleep schedule is shifted:

"Central to the goal of adolescent development is the transition from parental dependence to independence, all the while learning to navigate the complexities of peer-group relationships and interactions.

One way in which Mother Nature has perhaps helped adolescents unbuckle themselves from their parents is to march their circadian rhythms forward in time, past that of their adult mothers and fathers.

This ingenious biological solution selectively shifts teenagers to a later phase when they can, for several hours, operate independently—and do so as a peer-group collective.

It is not a permanent or full dislocation from parental care, but as safe an attempt at partially separating soon-to-be adults from the eyes of Mother and Father. There is risk, of course. But the transition must happen. And the time of day when those independent adolescent wings unfold, and the first solo flights from the parental nest occur, is not a time of day at all, but rather a time of night, thanks to a forward-shifted circadian rhythm."

edit: putted a little more space in between sentences

That is unrelated to the school schedule. Most bus drivers aren't going to care if their routes start at 6, 7 and 8am or 8, 9 and 10am.

There is also an issue of avoiding the 5pm rush hour when heading home.

I agree that the proximal driver is cost cutting.

But it’s largely tolerated because of the widespread cultural belief that waking up early is “character-building”. As if a late-shifted chronotype is a sign of laziness and sloth.

Also so students are at school before parents need to be at work. School is child care for a lot of parents.

Also sports! This is a big one, as high school sports are the lifeblood of many a small town. Ending school early lets kids cram in their 2+ hours of bashing each other's heads in for the amusement and profit of locals before they do 2+ hours of homework.

School being miserable, largely useless, and a huge time sink just makes sense to most Americans.

Teach kids formal logic/CS, assign reasonable homework, and have them get up at reasonable times? Nah!

N=45 is relatively high power for simple analyses, like a t-test (not sure if that's what the paper did).

You can detect an effect size of 0.6 with 80% power when N is 45. You can also detect a effect of 0.7 with 90% power at N=45.

There are other things that can make results unreliable, like p-hacking, but a sample size of 45 is not a sufficient condition for bad science.