Hacker News new | past | comments | ask | show | jobs | submit login
The Economic Consequences of Increasing Sleep Among the Urban Poor (oup.com)
230 points by rustoo on April 11, 2021 | hide | past | favorite | 202 comments



Those in the study were low-income adults in Chennai, India who sleep only 5.5 hours per night on average despite spending 8 hours in bed.

The key takeaway was:

   > increased nighttime sleep had no detectable effects on cognition, productivity, decision-making, or well-being, and led to small decreases in labor supply.
I find the result surprising. When I get under 6 hours I see a clear drop off in performance.


The sentence before that is: "Contrary to expert predictions and a large body of sleep research".

Was this study better science that disproved the existing body? Or poorer science? Or is there something problematic about sleep in Chennai? Or special about the people in Chennai?

The full paper states:

> An enormous body of research, mostly conducted in sleep labs in rich countries, documents severe negative impacts of sleep deprivation on a range of outcomes from attention and memory to mood and health (Lim and Dinges, 2010; Banks and Dinges, 2007).

> While experimental evidence on the impact of increasing sleep in field settings is scarce, there is a widely-held belief among researchers and the public that reducing sleep deprivation would lead to improvements in economic outcomes (Walker, 2017).

> To document these priors, we surveyed 119 experts from sleep science and economics who predicted sizable economic benefits, including a 7% increase in work output, of increasing sleep by half an hour per night from the low levels observed in our setting.

Social science is fun.


It could also be a function of their jobs, which weren't specified in the abstract.

While insufficient sleep might cause physical discomfort and contribute to long-term health problems, if their job weren't highly physically or mentally demanding, I suspect that most people could get through the day with negligible detriment to their short-term economic output after having a cup of coffee.


They employed 452 adults for a one-month data-entry job, which the authors say it's "a relatively cognitively-demanding task intended to be sensitive to sleep deprivation."

As a side note, the study also says that short afternoon naps increased productivity.


Because of a combination of health, family, and time zone issues, I sleep approximately 5 hours a night (6 or 7 on weekends, if I'm lucky). I also have a complex work environment where the ability to think quickly, have excellent recall, and make quick decisions is paramount (I manage two dev teams working on two very different code bases, facing very different challenges). The people I work with are often "the smartest person in the room" and notice slips and mistakes.

Anyway, I get by through a combination of sneaking naps, trying not to sabotage myself by eating/living poorly, and catching up when I can.

I suspect the people in this study do the same. They probably doze when on public transportation, or trying to get the kids to sleep, you'll lay down with them and sleep a little. These stolen moments add up. Also, learning to recognize the signs of mental fatigue - if you can't get rest, then, you have to slow down and double check everything, not get irritable, and defer major decisions.


I'm...extremely skeptical a generic "data entry job" is "high cognitive demand".

I can write new applications (atrociously) on basically no sleep, so I'm pretty skeptical "sit at this desk and enter these things" swings one way or the other (or even has much of an ability to quality check - at least the compiler will yell at me when I'm egregiously wrong).

I'd be far more interested if these people could be trusted to run heavy machinery on that schedule, or engage in a creative or hands on task like carpentry or welding. I suspect the results would be quite different.


I just got a good laugh out of the image of a study putting sleep deprived people in charge of heavy machinery for science.


They're called grad students :)


I'm...extremely skeptical a generic "data entry job" is "high cognitive demand".

Same here. While writing the GP comment, I considered using that exact example as something that I wouldn't expect to be heavily impacted by moderate sleep deprivation.


You're not "economically poor". If the economically poor had such creative jobs, our economy would work very differently.


I agree with the claim that they are sensitive to sleep deprivation, though.


Chennai's extremely hot. Having been there, intuitively I'd suspect a Spain-like siesta would work very well there and boost productivity.

The nights there are extremely warm too. I wonder if that's a factor in ensuring that 5.5 hours of sleep is no worse than 8?


I don't know how well it compares to a spanish siesta but the abstract ends with "In contrast, short afternoon naps at the workplace improved an overall index of outcomes by 0.12 standard deviations, with significant increases in productivity, psychological well-being, and cognition, but a decrease in work time."


*5.5 vs about 6. The study increased their sleep by 27 minutes, they were still under-slept by 2 hours.


AFAIK not anything below 8 hours qualifies as “under-sleeping”; instead, the need of sleep typically varies between 6 to 9 hours for healthy adults.


Which averages out to 7.5. So the average should have been in that range with outliners at 6 and 9


Wow. That should have been in the abstract. 452 adults hired for a one-month job intended to be sensitive to sleep deprivation sounds pretty robust.


The average teacher’s job is reasonably mentally demanding but despite waking and starting work at unnaturally early hours (in the US and China) people do acceptably with coffee. The students do worse because the schedule is even more divergent from their natural sleep schedule and they’re less likely to have coffee or other stimulants.


> people do acceptably with coffee.

Do they, though?


Technically, yes. They do well enough that we can and do accept it.


Yeah but not that long ago people accepted not having plumbing. There's no reason to be confident that things couldn't be much better.


> Technically, yes. They do well enough that we can and do accept it.

You shouldn't, and a great many in the US don't.


Given the attendance rate at private schools (low) and their divergence from the normal public school schedule (low) this doesn’t seem accurate. People may complain but they don’t do anything.


What time do they start work in the US?


My daughter's school starts at 7am, so she has to be up by 5:45am. It's stupid.


In my country it's the same, I think it is done that way because most people jobs start at 8 or 9, there's no school bus system, only private transport for kids going to school, so this schedule gives a chance for parents to drop off their kids at school and make it to work afterwards.

Personally I hated it at the time, because getting up early is not my thing, but now I appreciate the time I got to talk with my parents on my way to school thanks to that schedule arrangement.

Also to offset this early getting up, we jus went to bed earlier, like at 9pm or 10pm max, so not sure it really made a difference on anything.


> The educational effects of school start times Delaying secondary school start times can be a cost-effective policy to improve students’ grades and test scores

> The combination of changing sleep patterns in adolescence and early school start times leaves secondary school classrooms filled with sleep-deprived students. Evidence is growing that having adolescents start school later in the morning improves grades and emotional well-being, and even reduces car accidents. Opponents cite costly adjustments to bussing schedules and decreased time after school for jobs, sports, or other activities as reasons to retain the status quo. While changing school start times is not a costless policy, it is one of the easiest to implement and least expensive ways of improving academic achievement

https://wol.iza.org/uploads/articles/181/pdfs/educational-ef....


I grew up in rural Canada, and we had busses. Some kids came in from 60+ miles away. I recall quite a bit about school, and yet no one really complained about getting up at 5 to 6am.

Of course, most kids lived on farms, some even had chores before going to school, and early to bed, early to rise was normal.

We had a few antenna TV stations, no cable, VCRs weren't around for the average family, and of course no Internet.

We also didn't have city street lights / ambient light, street noise, the sound of neighbours.

People have gotten up early to do farm work for aeons, and go to sleep early too. In fact, to be more precise, staying up past 8 or 9pm is an urban / modern aberration.

Point is, staying up late is the problem. Nothing more.

Now of course, society has changed, so maybe change is needed. However, there is also a lot of counter literature on even TV as a sleep depriver. And now we have phone in bed, with a glowing screen, keeping a mind active.

My point? OK, change the time. However, will kids just stay up even later?

Or, as they do now, will they think "I should go to sleep now, or I will be tired tomorrow, but just one more text..."?


Staying up late is much easier then getting up early. Anyone who gets up early and then has to be anywhere can speak to the general paralysis that involves, since the entire activity has to be planned around a very sharp time-based shutdown.

Stealing hours later is a lot easier, because any amount of sleep will still break up the day compared to none.

The other reason of course is that the real trick is just staying up longer then your parents: that's the only truly unsupervised freedom you have as a kid.


No major disagreement, but I will add this...

Eating too much, borrowing more money than you should, eating junk food, staying up too late, being addicted to your phone, texting whilst driving, perhaps these are all the same problem?

And like any animal, we need to be trained to control ourselves, when young, for our own good?


Most developed countries are far enough from the equator that the amount of daylight is very different during different parts of the year. Perhaps it would make sense to base the schedule around sunrise and sunset rather than around arbitrary numbers?


How exactly are we supposed to run a modern society without the concept of time?


You can have a time system based around sunrise.

I mean with most clocks also being internet connected computers it wouldnt be too hard to make a system where you measure time in hours after average sunrise in a tike zone.

That is where I live right now it's sunrise +3.

I'll reschedule the daily 'standup' to SR+3.5, the banks open at SR+3 and close at SR+11.

One major consequence I can see is that now we have north south timezones on top of east west.

This would break in the extreme north or south where there are days without a sunrise.


That's what time zones are. You're just proposing more granular time zones. And none of them can fix the problem that in a lot of places the days are just short in the winter.


Timezones don't account for seasonal changes in sunrise times, and DST is a poor hack that tries and fails. Using local solar time would be an improvement in that regard. On short days you just do less.


Timezones are a reasonable compromise between the desire for people to be up during the day, on one hand, and the need for a modern economy to be able to coordinate people over long distances, on the other. Turning up the dial all the way to the left here is going to cause a lot of problems.


As far as human biology is concerned, the entire concept of agriculture is a modern perversion. You can't use it to argue a particular behavior is the natural state.


And yet people get up before dawn to go fishing and hunting.

At no point did I cite biology. Instead, I validated that different wake-up times have existed in the past, and in fact still do.

When does the garbage man, the builder, the mechanic get up? The blue collar man? It isn't 8am, that's for sure. People I know in these professions of start work at 7am. Or earlier. I see them get to sleep by 9pm.

Get to sleep sooner, discipline yourself, as with anything else, it's just that easy.

Or that hard?


In the USA, school schedules are at least partially dictated by after-school sports. Classes need to end early enough that teams can practice in daylight.


Another argument for the separation of Sport and State.


Yeah we had those too, sun goes down at around 6pm all year round here though, training would take place 3pm - 5pm for extracurricular activities


Ah. That's indeed early.

In France kindergarten and primary school starts at 8:30 and ends at 16:30. Mid and high school at 8 or 9, never earlier.

This is very early for children and teens, really not physiological.


In Australia, at least where I am, from ages 5-17 school is generally 8:45 to 15:15.


That is really crazy early! Where is this?

My high school started at 08:10 (I think) and elementary school at 08:15 and those were the earliest starters in the neighbourhood. University luckily started around 9.


Poor people aren't doing brain work but instead do manual labor etc. It definitely should be a core part of any study to highlight this.


In my country poor people are: doctors and nurses who work at state hospitals(most of them), teachers at state schools, university professors(both state and private ones), engineers who work at such government facilities as nuclear plants and the like, scientists in general and also some government officials. All them make roughly 10-20% percent of what moderately skillful software engineer could make, in the same city and country. Just for the reference.


They probably make more than minimum wage workers at (fast food|restaurants|cleaning|etc) ? So even if they're relatively poor compared to skilled software engineers ( which is usually even more skewed because skilled ones often work for rich foreign companies that can afford a much better salary and still come out cheaper than engineers in their original country), they're still better off than minimum wage, who are the real working poor ( note that in some countries and cities minimum wage can be sufficient and wouldn't put you in the poor category)


Well not really. Actually minimum wage in Ukraine (where I live) is rather low, so businesses generally pay higher. Fast food workers are not on minimum wage.

In terms of salary a school teacher would make less or the same as McDonalds worker.

For example, McDonalds Ukraine pays an entry level worker -14 000 UAH ($500) monthly for 40 hours per week. School teacher makes minimum 5000 UAH ($180), +bonus(10-60%). Teacher who was awarded a "highest category" certification (that would be a very experienced one) and who will get all the possible bonuses and raises will make around 14 000 UAH, roughly.

Workers, cleaning personnel would make in the same ballpark 9000 - 14000 UAH ($300-500) at least in Kyiv. Selling phones in the store, work at supermarket also has a similar remuneration.

Average doctor salary (not nurse) is 9000 UAH, at least officially.

The reason is - most those highly skilled and highly educated workers that I've mentioned are paid by the government which does not have funds and desire honestly to treat these people well. They are remnants of decaying public infrastructure - Ukraine has de jure free universal health care and a very big amount of government-funded seats at state universities. Still it is better to work at school than at the factory probably.

You just have a stereotype of how certain things work, everything is not like US/Western Europe structurally. Higher education is not a ticket to a better life everywhere.


Ah, sorry, didn't know things are that bad in Ukraine. I'm from Bulgaria so i can assure you my stereotypes are mixed and i don't think everything is like in the US or Western Europe.

How's the new president doing? At first it seemed like a joke, but the little concrete things i've read about him post-election seemed OK.


Of course, I think you can really get the idea what is going on in Ukraine due to kind of similar circumstances. Sorry for being a bit too blunt.

New president I think is a bit better than the previous three but the whole situation kind of shows two things: 1) There is not much you can do in the country where oligarchs control everything. 2) There is still not much ideas for the future except some sort of a neoliberal 'reaganomics', further privatization and generally disengagement of the state from any meaningful public good iniatives.


The study took place in India where doctors are well paid and McDonald's workers aren't.


Sounds pretty unrealistic, what country do you live in?


He's arguing they're poorer than the average software engineer, not poorer than a factory worker. I'd put my money on Eastern Europe or South America.


To put it into context, no, these people make around the same as factory worker. Work conditions would be much nicer, still. Schoolteachers are considered 'poor' by other Ukrainians (who are not too well-off themselves) compared to other occupations without taking into account SW jobs and anything like that.


Maybe also south or south-east asia (aside from the asian tiger)?


Ukraine. I think it would similar in other post-socialist states where transition to market economy was not a big success. I would put Moldova, Armenia in the same ballpark, maybe certain poorer Central Asia states like Uzbekistan but I'm not 100% sure.


They employed 452 adults for a one-month data-entry job, which the authors say it's "a relatively cognitively-demanding task intended to be sensitive to sleep deprivation."


The same can be said for other drugs that raise monoamine neurotransmitter levels, such as amphetamines.


I doubt that a study 'Economic Benefits of Meth use on the Urban Poor' would be looked upon so well by the Ethics Board.


No, but you could say “ADHD medication”, much of which is very similar


Please stop repeating this anti-psychiatric talking point.

1. They are different chemicals.

2. They are administered by different means (inhalation is vastly more impactful than swallowing a tablet).

3. The doses for pharmaceuticals are much lower.

By repeating this argument you create prejudice against those of us who live with ADHD and rely on medication to function normally.


> Please stop repeating this anti-psychiatric talking point.

That's rich. Here's a prominent psychiatrist's view (who btw, supports and does prescribe amphetamine adhd medication):

"There's a lot of confusion around the difference between amphetamine and methamphetamine. On the one hand you have anti-psychiatry activists who will say that using Adderall for ADHD is exactly like giving kids crystal meth; on the other you'll have people who say that obviously normal amphetamine is okay, but meth-amphetamine is a demonic substance that will hijack your brain and destroy your life. The truth is more complicated.

Methamphetamine crosses the blood-brain barrier more effectively than unsubstituted amphetamine, but I'm not sure how much that matters since people take different doses of both, and a high dose of unsubstituted will end up with more reaching the brain than a low dose of meth. It seems to inhibit the dopamine transporter more effectively, which might matter, but I'm not enough of a pharmacologist to know how much. Meth takes effect more quickly, which seems to increase addictiveness in a sort of behaviorist sense where the sooner a stimulus gets reinforced, the more rewarding it will feel.

I think there's been a little bit more research since then, but the general takeaway - that the science doesn't support the vast gulf between these two drugs in the popular imagination - still seems true."[0]

[0]https://astralcodexten.substack.com/p/know-your-amphetamines


Yet methamphetamine is prescribed for narcolepsy and ADHD. The trade name is Desoxyn.

Note that you are also creating prejudice against an already marginalized group of people, a subset of whom may have undiagnosed ADHD.


Many countries in the WW2 era sold amphetamine based drugs as antidepressants, for "creating the right attitude", making your wife focus on housework, etc. (and other rather disturbing things). Essentially, drugging workers doing low-skill tasks to make them more cooperative or productive or something.

I wonder how much research was done at the time and has been done in retrospect.


And still in 2021 most people are entirely unaware that their affectionately named ”morning joe” contains other mind-altering chemicals in addition to caffeine: Harmala alkaloids that slow down the normal breakdown of neurotransmitters and slowly build up in brain fatty tissues, increasing tolerance and lengthening withdrawal symptoms to many months.


And the German Army in WW2 heavily used meth ( pervitin iirc) to keep focused and going on for longer


Sounds a lot like Brave New World


Which was written around that time (even a bit before) ...


Maybe do a retrospective study, but lack of prospective randomization would taint the results.


Stimulant overdosage can cause permanent brain damage.


That brain damage is not caused by the stimulants per se, but the rise in body temperature caused by stimulants. Don’t do meth on a hot day.


As does driving a car at 120mph in bumper to bumper traffic. Fortunately these things are outside the scope of this conversation.


I don't think it's necessarily incompatible even if it seems contradictory unless there's research that quantifies the harm as a function of sleep deficit. Could easily be some range of sleep deprivation in which you're just bad at things, you move slow, and you're unmotivated. Intuitively we'd think that it's directly proportional to the amount of sleep deprivation, but I don't know if I've seen research that makes that claim. It would be interesting to see more papers that lead to a model of the benefit of sleep as a function of the amount of time slept.


Good grief. It almost makes me question what information is missing from the abstract since I don't know how one can consistently run on fumes without it affecting cognition, productivity or decision making.


Throwaway as I don't want to admit that I feel permanently cognitively impaired.

Anecdotal, but I spent years not sleeping through university and sleeping in airports or on the train. Studied engineering and did a lot of hackathons and events and stuff. I figured out then that I didn't need full cognition or excellent decision making. I needed more hours cranking out work. I spent years sleeping just a few hours and often not sleeping on Saturday at all.

I do a lot less of that now as work never has 2AM deadlines but it is as though I am permanently in that 80% functionality state. I never felt that I got out of that state. I have never regained my ability to be detail oriented. I am still reliant on the crutches of spell check and Grammarly and my IDE to make sure I don't do something stupid. I use task lists for every little thing in my day.

So it is not that it does not impact cognition (at least in my case), it is that you get used to that impaired state and can't find a way back.

Only a year and a half removed from that, so maybe it takes more time, but I still feel heavily optimized for output over quality, even though that is no longer needed.

My baseline cognition was already impacted. More sleep just did not repair it.


From my own experience: go get therapy, meditation classes and Ritalin! It wasn’t until I turned 26 and got access to all three that I could finally _learn_ what concentration really was. I went through Highschool without having to study a single day, getting very good grades nevertheless - while being on very little sleep with a total lack of a regular rhythm. College didn’t go so well, but other interests and pursuits were fulfilling. Meanwhile, the rise of social media trained my attention span to be shorter and shorter and shorter - until I had finally realized I couldn’t reed a single page of a book without drifting away. The above mentioned three-part intervention worked because A) in therapy, I could get i) help how to navigate the day-to-day problems and ii) help understanding why and how I got to that point, e.g. learned behavior, but also genetic predisposition, B) thanks to the medication, I could experience a state of high focus I hadn’t had in years - maybe ever - and enjoy a kind of focused flow, where I was completely in charge of what I do (compared to a state of flow where you just follow external and internal impulses ) and C), meditation (especially in the time I took ritalin) helped me learn how to focus on something, let go of that focus, and re-focus again (I used headspace for that).

I cannot tell you if a change in my sleeping habits was the result of all that, if it has been a coincidence or if it preceded any improvements - but it certainly didn’t hurt the process.

Today, I don’t need therapy or medication anymore, can focus good enough on my work and in the stories my significant other tells me. I don’t get nervous anymore anytime I have to wait in a line, I do fewer mistakes, I can read a book and feel less bored, more happy. It’s something I had to learn, but I needed some help with that. It’s worth a try!

Today, I also realize a significant decrease in performance and happiness if I get a single night of bad sleep. Before I knew how my days could really feel, I didn’t care about that - but I’m sure I had been impacted badly, nevertheless.


recommending Ritalin to someone that has suffered or still suffers from insomnia is bad advice as it is notorious for inducing insomnia.


OP stated he’s 18 months out of insomnia, but the adhd-like symptoms still prevail up to a point where he is suffering so much that he hides his (or her) identity when speaking about it. He describes himself as “permanently cognitively impaired”. I used to believe in all that fear mongering about stimulants for years, but as long as you stick to your doctor’s prescription, start with low doses and pay as much attention as possible to yourself and how you react - through therapy supported by mindfulness - the risks are very low compared to the risks of having a “cognitively impaired” life. That state, however you label it, does not only hurt your performance at work, it hurts your relationships (healthy relationships are correlated with mental health and longevity), it increases your risk of car accidents (some of them kill) and it exposes you to financial risks. It’s not a good place to be, and I support everyone in that place with a simple message: go to a doctor, get therapy, get medication, be mindful about it.


Recommending Ritalin at all as a first response is dangerous as well...


If you would check again: it’s the third advice, not the first. You cannot get it without consulting a psychiatric MD, and at least in Germany, you have to commit to long term behavioral therapy as well. To make it as clear as possible: I would not recommend popping pills as a solution to the problems faced by the parent comment, but as a viable part of an integrated solution. Fear mongering doesn’t help anyone.


>From my own experience: go get therapy, meditation classes and Ritalin!

This is your first advice. Anyway, no need to get pedantic. Fact is you're carelessly suggesting the use of some pretty heavy and specific medicine, to someone you don't know, based on a few words of text he wrote on an anonymous internet forum.


What degree of heaviness is okay for drugs to be an okay recommendation on a quite specific problem? Did you ever recommend someone to get an Aspirin due to headache? Hope you didn’t - Aspirin is so dangerous, there’s no way we would allow it on the market according to today’s regulation. That said, the point here cannot be the danger of medication, but the public perception. Ritalin in adults is very safe if prescribed and monitored by a doctor and supervised by therapy. Taking into account the rate of comorbidities of untreated adhd symptoms (btw, as far as science goes, it’s a spectrum, not a classification, so you’re higher high or low in such treats), such as depression, implying Ritalin were dangerous even if taken as a part of a broader treatment regimen, is much more dangerous.


It depends on when you take it.


Since I had a child, I started questioning whether cognitive decay in aging people was really caused by aging or a change in sleep patterns. Now my kid makes his nights mostly without problems, but the ~2 years of insufficient sleep feels like it had a toll.


I totally agree.

My sleep was somewhat destroyed from having kids. Not that I was extremely underslept, but my brain somehow stopped sleeping deeply it felt like. I awoke from every minute sound the kids made.

Today theyr'e 7 and 9 and I still wake from silly sounds.. Some sounds the kids make is like driving a knife through my ears. It is getting better but still...

The upside from this is now I don't need anywhwre near 8 hours of sleep anymore! 7 hours is almost too much, 6 works perfectly most of the time. 5 hours though is when I get into zombie-mode during daytime.


Same. I mean there are probably multiple factors in play but I can't imagine the interrupted sleep, plus the baseload stress and anxiety, are good for long term mental health. Hoping its counteracted by long term benefits of rewarding family relationships.


From your description, it's possible that you have undiagnosed ADHD, though probably not caused by lack of sleep. It's always worth talking to a doctor about these things — there might be a way to get your focus back.


I second this. I have been diagnosed with ADHD as an adult, and my experience, before medication, sounded very similar.


There's little evidence that this is sleep related. There are a lot of people who aren't detail oriented and rely on spell check, for a very wide variety of reasons.

If you feel this has impacted your life to the point where you need to hide your identity, maybe you should try therapy or a medical examination. Or just get more sleep


Well, humans are also extremely error prone. Spell check, IDE helpers, delinters, automated testing, etc, all help check that things are correct automatically, which saves huge amounts of pain.

I personally would always put more faith in someone who carefully checks their work than someone who thinks they don't need to. The second person is making mistakes and just doesn't realize it.


I had a similar experience from severe burnout - I was overly ambitios and worked for 12 hours + poor sleep. Its like you feel dumb and that you will never regain the clarity of mind. It took me a couple of years to get back to normal (around four I think). That included a year of therapy and a half of year of just doing the stuff that I like with no job commitment. Some downtime is needed.


Even when I'm "full focused" I still use stuff to automatic check my work (same as you). However I'm bit worried on how you seem functioning on "automatic"... I really do recommend going to a doctor.


If I have some auto checker i start to concentrate my errors into things the checker will find. Make errors that the compiler will find, so that once it compiles it should pass tests at once.


But why are you doing this to yourself? The impact of not getting minimum sleep will have all sorts of bad effects on your body, not just cognition. Try to find a balance and what you consider as permanent cognitive impairment may revert, but even if it doesn’t you don’t want to make it worse


The parent is not continuing the practice, and has not for 18 months.

It is noted in many sleep science studies that you cannot “recoup” lost sleep so this is plausible.


The insane stress levels from being in their situation also affects cognition.

So I am not surprised if merely looking at sleep amounts fails to explain differences.


Highly likely this is a confounding factor - and compensating for it is essentially every decent policy for the last 50 years in the West.


There is also a dynamic systems side to sleep rhythms. Quite likely there are stimuli you can randomly experience that shift your sleep cycle into a chaotic regime and then you need a good knock to the light and activity levels to reset to stability.


> increased sleep duration by 27 minutes per night by inducing more time in bed

Maybe 27 minutes is just not enough? I’m sure the results would be different if they started to get 7 hours instead of 5.5.


Possible "misaligned" is a better descriptor? I don't know about most people, but according to a sleep app I've been using for a while now, my REM cycles seem to be around 1.5-2 hours. Waking up at between cycles works well, adding a half hour does not.


My thoughts as well. They still got less than 6 hours a night, and were already in a state of constant sleep deprivation.


+1. Though remember we're talking averages, and different people have different sleep needs. One would think some of them saw enough increase in sleep quality to show up in the stats.


    > ... only 5.5 hours per night ...
    > ... increased sleep duration by 27 minutes per night ...
I'm not surprised. On average, they were still under 6 hours, if barely. And if the sleep problems are interrupt-driven, this study does not appear to account for sleep quality.


Ok, then we could assume the hypothesis: Either you sleep 8 hours and are productive or you go down to 5.5 because 6 wont increase your efficiency levels either.


The study also needs to examine:

- Noise pollution

- Air pollution and ventilation (PM2.5 and CO2)

- Bed comfort

- Temperature and humidity

Its possible that the home environment is so bad, that any increase in sleep yields no improvement. By contrast the workplace might be comparatively better controlled.

Getting rid of fossil-fueled cooking, power generation and transport solves some of these issues.


A lot of homes in crowded cities like Chennai and Bangalore are tightly packed, congested and poorly ventilated. Air (dust) and noise (human activity) pollution is very high. Within the same congested dwelling, there maybe people who have to get up very early and go to work or come home late and sleep late which disrupts everyone's sleep. So it is highly likely that there is only 4-5 hour window at night when things are quiet enough to get good sleep.


What does spending 8 hours in bed but only sleeping for 5.5 hours mean specifically, and how is this measured?

What is the expected amount of sleep for a healthy person that spends 8 hours in bed?


> What does spending 8 hours in bed but only sleeping for 5.5 hours mean specifically

It means that the TV is in the bedroom.


I'm not in India, and it's pretty common for me and my wife to spend time in bed that we're not sleeping, and I'm not talking about sex. I'm talking reading, browsing our phones, etc. We don't have a TV in there, but it's not a far stretch as I did when I was a kid, and so did my parents.


Not sure why you are downvoted but this is pretty common in India and could be a contributing factor.


For a healthy person in a good bed without interruptions, 8 hours. But if you have trouble falling back to sleep after being woken up, you can lose a fair amount in a noisy environment. If your bed is bad, you may wake up or not fall into a deep sleep. And there are medical conditions that can make you be unconscious but not actually sleeping. Plus, high stress levels interferes with sleep.


I read it as then saying they just got them to spend even more time in bed, despite the problem being they already have a lot of non-sleep time in bed. So it just reduced their time available to do other stuff. Am I misunderstanding?


I read the abstract like the managed through information to reduce the non sleeping time in bed. They shd have used a fitness tracker to confirm, relying on the answers of people who might think their income depends on giving the 'right' answers is dangerous.


> increased sleep duration by 27 minutes per night by inducing more time in bed


From the article or abstract?


That was just in the abstract, what you see on the first page clicking the link.


oh yes, thanks. I didnt parse the second half of the sentence. This totally doesnt make sense. I mean people seem to have a lot of interrupted sleep, wouldnt reduce the interruption increase sleep quality (and time)? (But probably due to small infants, so might be difficult to change that)


Is it so surprising? The key takeaway could be rephrased “Healthy humans living under conditions similar to our evolutionary past naturally sleep an optimal amount of time at night.”

> When I get under 6 hours I see a clear drop off in performance.

Or is it “When I temporarily find myself in an environment with stress-levels similar to those of the people in the study I a) start to perform like them on modern day tasks and b) start to sleep like them.”?


The better takeaway is that napping is awesome! Moving work time into nap time resulted in a net productivity increase! That's amazing.

If you consider taking 30 minutes of a 6 hour shift to nap, that means they have to be 10% more productive for the 5.5 hours after the nap. I'd suspect hawthorne here, even though it didn't show up in the night treatment group, but it would be interesting to see if this productivity increase is sustained in the long run.

>In contrast, short afternoon naps at the workplace improved an overall index of outcomes by 0.12 standard deviations, with significant increases in productivity, psychological well-being, and cognition, but a decrease in work time.

Time spent napping >> time in bed. They're sufficiently exhausted by mid-day to get higher quality rest than they would by spending the same time in bed.

If you're tired, you're better off getting up at your normal wake time, then taking a nap later.


I would look at the eight hours in bed as a possible explanation. While they weren't technically asleep, they likely still saw resting benefits just from laying down for a prolonged period of time.


> increased nighttime sleep... led to small decreases in labor supply.

This indicates to me that they found something better to do, than this study.


> When I get under 6 hours I see a clear drop off in performance.

Same. I have a hard line at 6 hours. Over 6 and I'm good, less than 6 and I'm dead all day. I don't use an alarm and wake up naturally after around 7 hours of sleep, but that last hour I'm normally aware of the lighter sleep stage I'm in.


That wasn't the entire result. What I took away was this:

>In contrast, short afternoon naps at the workplace improved an overall index of outcomes by 0.12 standard deviations, with significant increases in productivity, psychological well-being, and cognition, but a decrease in work time.


They increased the participants sleep from 5.5 hours to 6 hours per night and expected improvements in cognition. This is not how sleep works, AIUI. This is like expecting to get rich after overdrawing your bank account by $140 per week instead of $175 per week.


They were only able to induce a 27 minute increase, so still no more than 6 hours of sleep total.


Having stayed in an Indian city. Traffic noise and pollution is horrendous. I can see how these two factors would mess with sleep quality and duration.


Just imagine what we'll do to the labor supply if we can figure out a way to keep the poors working 24/7 and have them not suffer any ill effects from it!


This sort of inflammatory mind set is not helpful, and in this case the abstract describes they are actually getting adequate time in bed, just having interrupted sleep.

The causes of the interruptions could be manifold but i would hazard a guess that the primary cause would be interruption from young children in small domiciles and lack of could social responsibility within the neighbourhood.

I've experienced both having a young family and currently living in relatively low social economic neighbourhood. Just last night I was disrupted by someone deciding to burn something rather noxious at 0100 in the morning.


> This sort of inflammatory mind set is not helpful

Although not completely relevant to the topic, it's not outside the realm of possibility for what was stated to become a reality. And it's very much an important idea to explore, because to not do so would help those willing to exploit such "zombie workers" actually go through with it.


It has been the reality for some sets of society during particularly terrible periods within humanities history. Gulags, concentration camps, work gangs and any other element of human exploitation.

For these to work most often one needs to denigrate the peoples concern to the point where they are no longer even perceived as the same level of human. Sure all of that is possible but we wont have useful conversations or strategies if we're constantly elevating every instance of stratified to a slave like scenario.

I'm not convinced that there is really any other make up of society. The only way would be for us all to live as isolated self sufficient hermits.


That's why the idea presented - the idea that we can keep people awake 24/7 without negative consequences (or at least not enough of them to warrant alarm) - is so insidious.

It doesn't require anyone to subjugate or enslave anyone else.

Nor think of them as "sub-human" or try to convince a larger population that their exploitation is warranted. All it takes is for the substance or technology that allows for this 24/7 waking state to become legal and you're done.

The moment it's legal, warehouses, factories, the service industry, will start looking for people who can pull 10 hour shifts. If you can't do that then you can't have a job (or you lose an existing one.)

Then it goes from 10 to 15 hours. If you can't keep up, perhaps be cause you refuse to "augment" yourself, then you're unable to find work or loose your existing one.

This really isn't that far stretched.

Do you really think Bezos and his lot wouldn't be willing to invest in technologies that allowed an already underpaid workforce to go from 8 hour shifts to 15, 18 or 24 hours?

Of course they would.


>This sort of inflammatory mind set is not helpful

It's not inflammatory because it's an accurate description of the capitalist mindset. You wouldn't get a CEO to admit it out loud, but they all believe that in their heart, otherwise they would be replaced by someone who does.


This is not remotely unique to capitalism in the slightest. Those wonderful socialist "democracies" were just as exploitative, Mao, Stalin, Hitler, the lot of them exploited groups for the good of the state.


Hitler was a fascist, not a socialist. He swore to destroy the Soviet Union, pioneered privatisation, violently suppressed workers. And after all, the first taken to concentration camps were communists and trade unionists.


Britain’s Factory Laws were created to prevent 8 year olds from working 16 hours per day with only a single break, but weren’t really enforced until automation made child labour obsolete.

If we had the technology to force people to work 24/7 but proved to it was detrimental to people’s health, somehow I know deep down that society would just bite the bullet and people would burn the midnight oil for a few more dollars.


It probably wouldn't be a good idea because demand would collapse, and there's no work without customers.

This is actually why economics is called the "dismal science", it's not because everyone hates economists, a slave-owner gave it that name because he was mad economists didn't like slavery.


I’m sorry, but is this a joke? It’s well known the “dismal science” came from Malthus’s incorrect prediction of society’s collapse.



Given the low income/wealth of the people doing the work, that's not a convincing argument.

There's a reason why overall income didn't really go down in 2020 (and even increased in some places), and thats because poor people don't actually make that much money, nor do they provide any significant value.


> because poor people don't actually make that much money, nor do they provide any significant value.

I’d love to see this reasoning or study behind this, and the context of “poor people”.


Poor people’s income went up in the US, and the poverty level decreased, because we actually did a proper economic stimulus for once instead of an undersized one like in 2010.


Weird... maybe he was also mad at economists because they proved again and again that slavery was more expensive than paying people a wage!


That sounds counter-intuitive? Have you any literature that backs this up?


Adding to the previous comment, slaves also work much less effectively than employees because slaves have no incentive to try hard, since either way they will stay slaves.


Pretty much this... incentives matter. But if you’re a slave, what’s your incentive to work harder?

As for literature backing this up, Adam Smith in Wealth of Nations talks in detail about slavery in the American colonies.

He gives examples where slavery was only viable in the southern states where they grew tobacco. Maybe one of the reasons why the South were so opposed to the end of slavery vs the North where slavery was expensive


Read the abstract...


https://www.hopkinsmedicine.org/health/wellness-and-preventi...

This study used cognition, productivity, decision-making, and well-being as outcomes. It did not discuss the economic effects related to deleterious health from long-term sleep deprivation. Is higher productivity and output from increased time at work and decreased sleep time outweighed by the burden taken on by society from the other effects? I worry that some people will see this research and use it to feel better about making their employees work more hours and exploiting low income labor.


    short afternoon naps at the workplace improved an
    overall index of outcomes by 0.12 standard
    deviations, with significant increases in
    productivity, psychological well-being, and
    cognition
Is it possible to learn that? To me it seems impossible to do a "short nap". Even when I feel low energy, I don't feel like I could just lay down and sleep during the day.


Yes! It just takes practice.

I started out finding a comfortable position and relaxing with a timer set for 15 minutes. After years of practice, I now hit REM almost immediately and wake up feeling rested without a timer in 15-20 minutes.

It's easier for your body to learn if you have a specific place (e.g. a coach), time (e.g. immediately after lunch), and position (I cross my ankles and steeple my hands on my chest). These make it feel qualitatively different from night sleeping and easier to wake up naturally.

You also want to pay attention to sound and light. I use noise-cancelling headphones at work and earplugs + white noise at home. I choose a well-lit area, preferably with natural lighting, and then cover my eyes with a cloth or sleep mask. It's easier to feel refreshed when you uncover your eyes to bright sunshine, rather than waking up in a fully dark room.

Honestly, the main challenge is feeling self-conscious when napping at work. Originally I would lock myself in a shower room or go out to my car, but I'm finally self-confident enough to sleep on a public coach.


It's easy. In China most people do that at noon, even there's no bed around. People usually take a 20 mins nap at their desks. Preferably after lunch because it's easier to fall asleep because the blood sugar would rise after eating.

Sleep at a desk might not be the most comfortable thing, but it's not bad at all once you're used to it. Or get a small bed around if you can. Sleep masks are surprisingly helpful, too.

Just relax and don't be upset if you cannot fall asleep fast, even if you can't fall asleep you'll find yourself more productive in the afternoon - it's like an implicit meditation. There are also times that people only actually sleep like 5 minutes out of 20, but it usually subjectively feels much longer than '5 minutes' because time feels longer when sleeping and it's very refreshing.

As time goes by it will become a habit and you'll fall asleep fast. The downside is you are likely to feel worse if you have things to do at noon and miss the nap.

IMO the best thing about taking nap at noon is it reduces the fear of sleeping too little at night because you know you can more or less take a nap and get a partial reset at noon.


Why do you associate high blood sugar with more sleep? Could it also be something else, like the cooking oil used with the veggies and meat/tofu?


> Why do you associate high blood sugar with more sleep?

Maybe I'm wrong on the causation but I feel more sleepy if I eat more carbohydrate.

> Could it also be something else, like the cooking oil used with the veggies and meat/tofu?

Anything would do, it's just simply harder to sleep with empty stomach =P


Yes. I do 20 minutes of nap most afternoons, and it helps immensely. Though "nap" is a misnomer, I don't actually try to sleep, just sit or lie comfortably with my eyes closed and as few noises and interruptions as possible. A 20 minute timer has taught my body to get ready to work again after exactly 20 minutes. The goal is to let the mind relax for a bit.


I was in the same boat until I had a baby who was a _terrible_ sleeper during the night. Once I was down to 4-5 hours sleep a night, napping during the day was heaven!

Sometimes I'd have had too much coffee or been overstimulated through work or something, I found [these tips from the military](https://www.inc.com/jessica-stillman/the-trick-soldiers-use-...) really helpful. Even now, I pretty much only need to relax my jaw and do a few rounds of 4-7-8 breathing and I can have a nap on demand!


It might need some training, but it's possible. Especially when you are very tired from sleeping only 5-6 hours every day, it should be very possible have a very deep sleep even in a 20 minute "nap" (i.e., a real sleep loop that gets broken unhappily after 20 minutes).


> Is it possible to learn that? To me it seems impossible to do a "short nap".

Yes. If you have to look after an infant you too may discover how wonderful 12 minutes, or seven, of closing your eyes can be. Did I sleep? Maybe, but I definitely feel better.


Seems like different for each person and activities / health.

For me it's easier if I was sleep deprived after several nights, and when I've not exercised for long.


I was always told to avoid naps, but if you must do like 90 minutes. But in general you ideally want regular good amounts of sleep daily at the same times.


It’s great to see negative results like this, that go against current popular research trends, published. It makes me realise how rare it is to see “we studied this thing and contrary to our predictions saw nothing interesting”. Presumably because of publication bias.


True, but to be fair a null result is much more interesting (and thus publishable) when it cuts against a large body of prior empirical work or theory.

Thinking specifically of Card and Krueger (1994) finding zero impact of the minimum wage on employment


Perhaps the lack of measurable benefits was because the total sleep was still well under what we believe humans need.

Also the period of improvement was merely days. Maybe benefits take longer to begin to show.


Right. Suppose someone has been living on 1500 calories per day for a while. If researchers increased his intake to 1700 calories day they may not be able to detect a significant improvement. That doesn't mean undernourishment isn't a problem!


This was my instinctual response as well. However I agree with another poster that I am happy to see a "negative" result published.


This treats only short-term effects and relies on a small (0.45 hours) self-reported increase in sleep time obtained by just telling people to sleep more. Effects on children are totally absent.

It's not sufficient to even reduce interest in improving sleep quality because it doesn't measure most of the effects and the methodology is questionable: did participants accept, e.g., lower-quality meals in order to find more time to sleep?

It does show that rich people telling poor people what to do rarely produces any improvement — we've seen that before.


Here's the full study pdf:

https://economics.mit.edu/files/16994


Yes, the full study explains a lot. I don’t think they can come to the conclusion that “increased nighttime sleep had no detectable effects on cognition, productivity, decision-making, or well-being” based on the data they’ve shown.

1. Their interventions increased sleep time only by increasing time in bed, not sleep efficiency. In other words, without interventions, if participants were sleeping for 5.5 hours with 8 hours in bed, after their interventions, they slept 6 hours after 8.5 hours in bed.

2. This means that the night sleep they measured post-intervention was still extremely disturbed. I doubt if it was restorative in any way.

3. The nap time at work WAS probably of much higher quality because the environment was much better.

4. A word on the interventions; I cannot figure out why they didn’t give out mosquito nets or repellant given that they correctly identified mosquitoes as a major problem (reported by 70% of participants). The best way of getting a good night’s sleep with mosquitoes around is with nets and the second best is some kind of repellant.

5. I think the real conclusion should be that sleep quality matters. Not just amount of sleep, especially if it’s disturbed.

I feel like the conclusions are slightly post facto. As in, they set out to test their interventions and didn’t end up proving them so they switched to nap time.


I agree with your assessment that 'more of something bad' is not necessarily better.

In addition it should be noted that the study relies on actigraphy, yet the shortcomings of actigraphy are waved away. This doesn't mean we can get good before-after estimates, but they should not be compared to estimates from PSG.


Poverty is not simply a financial condition. It is - for lack of a better term coming to mind - a disease; and certainly not a diseaae anyone chooses. In fact, poverty creates tunnel vision. It limits vision. It, in the minds of the impoverished, limits choice.

It's complicated.

Matt Desmond's "Evicted" was a profound moment for me. Similar to this study on sleep, he highlights how areas of higher eviction rates ultimately destabilize the broader community. That feeds back into the disease and the cycle perpetuates, like a virus.

https://www.evictedbook.com/


They mentioned that sleep efficiency was already poor. They mentioned that the increase in sleep was achieved through increased time in bed, not increased efficiency.

Most of the restorative benefits of sleep happen during long stretches of uninterrupted sleep. If the sleep efficiency problem is due to multiple interruptions to the nights sleep, that is a very different thing than people having a hard time getting to sleep, but staying asleep once they are out.

If the underlying sleep efficiency issue isn't addressed, it's not really all that surprising that there wasn't a measurable improvement in productivity.


In California, rental apartments are built to a lower standard than condos. In particular, they don’t require noise proofing between units.

Noise proofing interior walls costs almost nothing (something like 1% the price of construction), but has a huge impact on quality of life.

I’m continually shocked at the systematic discrimination built into California housing.


the standards for noise proofing apply to all construction (condos, townhomes, apartments) https://www.astm.org/DIGITAL_LIBRARY/STP/PAGES/STP35976S.htm


While 27 minutes nighttime sleep didn't affect outcomes, another effect they observed was that afternoon naps DID increase productivity and well being. So it's not that more sleep can't help -- maybe it depends on specific type of work / life situation?


Naps are great. Taking 20 minutes of nap turned my afternoons from distraction zone into my most productive time.


I wonder how much of the conventional wisdom on sleep is wrong. I know a lot of people (especially post military) who claim they have essentially trained themselves to live adequately on 5 hours or less a night. But most sleep studies seem focused on short-term changes or average populations.

Maybe I'm weird, but I hate sleep. If I had the option to function off of 3-less hours a day, that would be like getting back 45 days worth of my time every year.


Per design the scientific method can only make claims about large samples or 'averages'. If we assume a claim is normally distributed there will always be folks in the left and right tails which are not average - in fact 32% will lie outside of one standard deviation!


Looked initially like a ripe candidate for the ignobel prize. But, it seems to distinguish sleep from hours in bed and finds that less sleep than time-in-bed doesn't seem to affect them much. Wonder if the type of work was the reason for their different conclusion - assuming that the poor were involved in more physical labor kind of work while the other studies it mentions were probably not.

Edit: adding the link to an article I happened to have open: https://www.mckinsey.com/business-functions/organization/our...


> “finds that less sleep than time-in-bed doesn't seem to affect them much”

The abstract of the article doesnt say this. It finds that the intervention managed to increase their average sleep length by 27 minute from 5.5 hours to ~6 hours. Thats still way bellow the recommended length. It also finds that this intervention didn’t improve their work performance.

This might be because “less sleep doesnt seem to affect them much”, but it might equally well be that it affects them tremendously and the 27 extra minutes were not enough to help them.


You are right and your explanation is more precise. The fact there was no cognitive or other change due to the 27 extra minutes implies my interpretation. It's possible that the baseline using 5.5 hours of sleep is not the right one to use and 8 hours of sleep might show a positive impact, which the extra 27 minutes is not showing.


I'm a 62 year old software developer. My normal sleep is between 4 and 5 hours with occasional 6 hour sleep according to my Fitbit. Anything less than 4 and I feel tired but I'm putting in a full days work with four or more hours sleep.

In the past while driving long distances, if I started getting fatigued, pulling over to a Motorway services I could fall asleep for 20 minutes and that freshened me up enough to finish any journey.


Are you a former professional driver?


No offense, but why was this question even asked? What are the people's needs in the first place? I saw a similar study that suggested the best way to improve mental health and economic consequences among the poor is to *drumroll give them money. Then they will create sustainable interventions that don't require source of money to improve the lives.


Plenty of offense: why are you even asking why they're doing research into ways to improve people's well-being, especially poor people? Yes, giving money helps, I'm all for UBI, but maybe there are other approaches that are cheaper or complement UBI. How about we find out and _improve people's lives_?


Could you give people money and allow them to take a nap?


This is brilliant science. Spending more than 8 hours in bed isnt necessary, but naps are still helpful. With young children 5.5 hours in bed is not abnormal.


It would be great if we could look at the sample data size, look at its distribution, and type of significance tests used for this study.


Earplugs are cheap. Helps you sleep.


That depends on the whether they produce discomfort, frequency of the noise, whether the wearer has tinnitus, blah blah blah


The majority of comments seem to have the belief that the need for 8 hours of sleep is truth, and seem to mostly be making up various excuses why the increase in sleep here doesn't show results.

As far as I can tell, the 8 hours figure is on pretty shaky grounds and most believe it due to pop-science books like 'Why we sleep' and it could easily be the case that this is just another study showing how exaggerated that claim is.


Between 7 and 9 hours of sleep has been recommended from every sleep research group I can find, long before that book came out.

Recent consensus statement: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4434546/


Long before that specific book came out. If you look at how they arrived at the recommendation here, a lot of it was based on discussions and voting by 15 experts chosen by the US Department of Health.

Actual studies are much less conclusive (see the one we are commenting on for example) and the evidence for 8 hours of sleep is shaky and the difference from 6 to 8 is rarely especially big even when it is supported with anything under 6 and over 8 having negative effect.

Check this systematic review (first result of my search[0]) which seems extremely sympathetic to 8 hours, yet the actual results are:

>compared with 7 h of sleep per day, a 1-h decrease in sleep duration was associated with 6% increased risk of all-cause mortality and a 1-h increase in sleep duration was associated with a 13% increased risk of all-cause mortality (N = 241 107 adults in 43 articles)

So, going from 7 to 8 hours increases risk more than going from 7 to 6!

Further

>Itani et al. (2017) reported that short sleep duration (<6 or ≤7 h/day) was not significantly associated with the incidence of depression compared with normal sleep duration (N = 16 257 adults in 2 articles)

>Lo et al. (2016) reported that extreme sleep durations (both short and long) were associated with cognitive decline compared with the reference sleep of 7 to 8 h/day (N = 97 264 adults in 18 articles)

But again it's only at the extremes that there is decline, which seems to be more like 3+ hours less than 8 a day.

>Health-related quality of life No systematic review was identified that examined the association between sleep duration and health-related quality of life.

etc. If you go through actual studies and systematic reviews it is really hard to make much of a case that 6 hours is much worse (if at all) than 8, yet alone anything more than that.

0. https://cdnsciencepub.com/doi/full/10.1139/apnm-2020-0034


This is one of my favourite topics that seems straightforward (What's the optimal sleep length?) but is a lot more tricky.

> If you go through actual studies and systematic reviews it is really hard to make much of a case that 6 hours is much worse (if at all) than 8, yet alone anything more than that.

The absence of evidence that 6 is much worse than 8 hours is not evidence that 6 is not much worse than 8 hours. It doesn't matter that much in this case because we already agree that it's worse - the question is how much worse.

Better or worse is measured in averages, on a population level, and here we see exactly the adverse health outcomes you cited (and a lot more that you didn't cite) from [1].

Here is where things get tricky for two reasons:

1) Population studies don't translate into personal health advice - there are plenty of folks striving on 4 hours a night (but they are rare in relative terms).

2) Overly long sleep durations are also associated with adverse health outcomes, and we don't know why! We believe we have a good understanding why short sleep is linked to some health outcomes linked to certain metabolic pathways, e.g. obesity or diabetes. And also we can take one individual, restrict their sleep, and see that their cognitive performance is impaired, and from here, it is reasonable to assume we understand the link between short sleep and accidents and injuries.

For the overly long sleep however, we have no idea (as far as I'm aware of).


>The absence of evidence that 6 is much worse than 8 hours is not evidence that 6 is not much worse than 8 hours.

It's not absense of evidence as in hasn't been tested - they have been compared and it doesn't really come off as worse or at best only a little worse (and in some cases better than 8).

>It doesn't matter that much in this case because we already agree that it's worse - the question is how much worse.

Who is this 'we'? My whole point is that people have this assumption and keep looking for ways to justify it even when confronted with evidence that it might not be the case as in the study posted here or the systematic review I posted.

>and here we see exactly the adverse health outcomes you cited (and a lot more that you didn't cite) from [1].

But we don't see that. What I cited was that the evidence doesn't even suggest worse outcomes at 6 vs 8 hours in the biggest analyses out there.


I don't understand. The study you cited, a meta-analysis, reviews the adverse effects of short and long sleep on

* Mortality

* Incident cardiovascular disease

* Incident type 2 diabetes

* Mental health (incident depression)

* Brain health (incident cognitive disorders)

* Cognitive function

* Falls

* Accidents and injuries

and six other outcomes. The authors conclude:

> Conclusion

> A comprehensive body of evidence supports the presence of a U-shaped association between sleep duration and health outcomes in adults. Dose–response curves showed that the sleep duration that was most favourably associated with the health outcomes that were examined was around 7–8 h per day in adults, with no apparent modification of the effect by age in the few studies that looked at it.


I specifically cited the actual results from the meta-analysis. In the conclusion and abstract they seem to mostly talk about 7-8 vs really short or longer sleep but when you look at the analysis there's barely any adverse effects at 6 (and indeed 6 is better than 8 and only a tiny bit worse than 7 on the most important thing from most studies - all-cause mortality).

Yes, of course sleeping, say, 2 hours a night is too little. My claims and quotations were about 6 hours, which is roughly what the people in OP slept, too.


It seems to me you are picking one outcome, all-cause mortality (link to the study in question with nice dose-response curves [1]) but ignoring cardiovascular disease, type 2 diabetes, brain health, cognitive function, falls, accidents and injuries, and obesity?

> My claims and quotations were about 6 hours, which is roughly what the people in OP slept, too.

It's not clear how comparable the numbers are. The study from OP [2] reports sleep as measured by actigraphy (5.5h), time in bed (8h) and self-reported sleep (7.2h). What the meta-analyses most likely have studied (I haven't checked) is self-reported sleep.

[1] https://www.ahajournals.org/doi/pdf/10.1161/JAHA.117.005947

[2] https://economics.mit.edu/files/16994


I cited 4 outcomes, starting with both the most important one and the one with most studies and subjects behind it. There wasn't an outcome where the big negative effect is there at 6.

You are proving my point - even when presented with data against the 8 hours myth you try to twist it in every way to confirm your prior belief and wouldn't even consider if the data might just be correct.


The absence of evidence that 6 is much worse than 8 hours is not evidence that 6 is not much worse than 8 hours.

If sleep studies show that 6-hour sleepers do better than 8-hour sleepers on a variety of metrics... that definitely counts as evidence.

It doesn't matter that much in this case because we already agree that it's worse

The parent comment literally cites a study that suggests 8 is worse than 6.


This estimate is quite robust, e.g. researchers observed how long different hunter-gatherer societies sleep etc.

In addition it should be note that it's distributed like a Gaussian distribution, so there will be plenty of people outside this range.


I need probably 7.5-8 hours of sleep. I'm very confident about this. If I get only 5-6 hours sleep for a couple nights, I become quite cognitively impaired; if it goes on long enough there are serious emotional effects too.

There are people who insist that actually, 5-6 hours is fine, and that I must be lying, lazy, or deluding myself. These people are trying to make me stupid and miserable.

It's an issue that provokes a lot of strong emotions, especially on the side of people who feel pressured to sleep less than they need.


>It's an issue that provokes a lot of strong emotions, especially on the side of people who feel pressured to sleep less than they need.

Perhaps you feel like it is much worse for the side you perceive yourself to be on. I, and plenty of other people have had very negative experiences and sleep-related anxiety because of all the people insisting that getting less than 8 hours of sleep is bad for you on flimsy evidence.


I agree with your analysis above -- a lot of the causal claims trying to connect <8hrs sleep to bad health outcomes are pretty dubious. People shouldn't worry about their lifespan or dementia or whatever. "Why We Sleep" unfortunately seems to have serious flaws.

However I really do maintain that the anti-sleep attitude is much more common. There is always huge pressure in schools, the workplace, social life to cut into sleep.

I think the reason "Why We Sleep" became so popular without facing much scrutiny is because many people were facing these pressures and desperate for some countervailing authority to point to.


Surely you concede that, even if 5-6 hours is not enough for you, it might still be enough for them.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: