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.
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.
> ... 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.
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.
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?
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.
> 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.
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 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.
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.
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.
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.
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.
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.
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.
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.
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?
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.
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.
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.
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.
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.
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.
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.
[+] [-] schappim|4 years ago|reply
The key takeaway was:
I find the result surprising. When I get under 6 hours I see a clear drop off in performance.[+] [-] Scoundreller|4 years ago|reply
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.
[+] [-] A4ET8a8uTh0|4 years ago|reply
[+] [-] methyl|4 years ago|reply
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.
[+] [-] __te__|4 years ago|reply
[+] [-] ArkanExplorer|4 years ago|reply
- 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.
[+] [-] gnopgnip|4 years ago|reply
What is the expected amount of sleep for a healthy person that spends 8 hours in bed?
[+] [-] jonplackett|4 years ago|reply
[+] [-] bjornsing|4 years ago|reply
> 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.”?
[+] [-] abandonliberty|4 years ago|reply
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.
[+] [-] pumaontheprowl|4 years ago|reply
[+] [-] teachingassist|4 years ago|reply
This indicates to me that they found something better to do, than this study.
[+] [-] matwood|4 years ago|reply
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.
[+] [-] AndrewKemendo|4 years ago|reply
>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.
[+] [-] GIFtheory|4 years ago|reply
[+] [-] rattray|4 years ago|reply
[+] [-] dukeofdoom|4 years ago|reply
[+] [-] unknown|4 years ago|reply
[deleted]
[+] [-] llamataboot|4 years ago|reply
[+] [-] Ghostt8117|4 years ago|reply
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.
[+] [-] TekMol|4 years ago|reply
[+] [-] _pastel|4 years ago|reply
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.
[+] [-] namelosw|4 years ago|reply
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.
[+] [-] larsrc|4 years ago|reply
[+] [-] dtjohnnyb|4 years ago|reply
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!
[+] [-] nednar|4 years ago|reply
[+] [-] barry-cotter|4 years ago|reply
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.
[+] [-] fendy3002|4 years ago|reply
For me it's easier if I was sleep deprived after several nights, and when I've not exercised for long.
[+] [-] th0ma5|4 years ago|reply
[+] [-] nojs|4 years ago|reply
[+] [-] blunte|4 years ago|reply
Also the period of improvement was merely days. Maybe benefits take longer to begin to show.
[+] [-] scythe|4 years ago|reply
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.
[+] [-] Scoundreller|4 years ago|reply
https://economics.mit.edu/files/16994
[+] [-] shash|4 years ago|reply
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.
[+] [-] chiefalchemist|4 years ago|reply
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/
[+] [-] moron4hire|4 years ago|reply
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.
[+] [-] hedora|4 years ago|reply
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.
[+] [-] jakubp|4 years ago|reply
[+] [-] larsrc|4 years ago|reply
[+] [-] legitster|4 years ago|reply
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.
[+] [-] astatine|4 years ago|reply
Edit: adding the link to an article I happened to have open: https://www.mckinsey.com/business-functions/organization/our...
[+] [-] davidhbolton|4 years ago|reply
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.
[+] [-] anticensor|4 years ago|reply
[+] [-] jonesn11|4 years ago|reply
[+] [-] dr_dshiv|4 years ago|reply
[+] [-] yosefjaved1|4 years ago|reply
[+] [-] redmeatforchina|4 years ago|reply
[+] [-] Tenoke|4 years ago|reply
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.
[+] [-] bdibs|4 years ago|reply
Recent consensus statement: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4434546/
[+] [-] currymj|4 years ago|reply
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.