Theses on Sleep(guzey.com)
guzey.com
Theses on Sleep
https://guzey.com/theses-on-sleep/
101 comments
I lived in a lavvo from august 2015 to April 2016, and it was the most awesome year ever (including in terms of sleep). I had a nice setup with a platform covered with sheep skins, and two sleeping bags (it reached -15C that winter in southern Norway).
Back when I was younger (10-14) I slept outside more than half of the days of the summer. In the barn, under trees, in trees, far into the forest, often accompanied by my horse, dog and cat. The feeling of waking up outside is so nice. In the forest, the first birds in the morning waking you up, finding new places and exploring. I had capes, some of wool, one of reindeer skin, and that's all you need to be comfortable during the night. I used to ride my horse far into the forest and we would just stay there until the next day. Playing flute, doing woodworking or reading while the horse was grazing.
Back when I was younger (10-14) I slept outside more than half of the days of the summer. In the barn, under trees, in trees, far into the forest, often accompanied by my horse, dog and cat. The feeling of waking up outside is so nice. In the forest, the first birds in the morning waking you up, finding new places and exploring. I had capes, some of wool, one of reindeer skin, and that's all you need to be comfortable during the night. I used to ride my horse far into the forest and we would just stay there until the next day. Playing flute, doing woodworking or reading while the horse was grazing.
That period from 10-14 sounds mindblowing! Magic. I'm guessing your folks had a summer house in Norway or something - I love that you had that freedom.
Hunter gatherers supposedly sleep less and get upt before dawn, those behaviour patterns are our best bet for what the past sleeping cycles were.
Climate-wise, this applies to hot places as well. I spent a few years in upcountry subsaharan Africa. Sleeping indoors was suggested and encouraged because it made it easier to set up anti-mosquito bed nets, but actually doing so was a challenge, and virtually impossible when it was humid. Much more comfortable to lay out on a bamboo frame with a sheet and hope not to get malaria that night.
Are you seriously arguing that sleeping out in the nature, potentially with dangerous animals around you, on bear skins, with several friends (on the same bear skin?) is as comfortable as sleeping on a modern mattress in your home?
There have been studies that confirm sleeping outside results in sounder and healthier sleep.
I think about it in terms of germs. Yes, on paper it's more safe to sanitize everything, but in doing so we prohibit our ability to build defenses, and actually become less healthy.
In the same vein, maybe by sleeping on mattresses indoors all the time, we fail to build a tolerance to adverse sleeping conditions, and maybe get more sensitive to them too.
I think about it in terms of germs. Yes, on paper it's more safe to sanitize everything, but in doing so we prohibit our ability to build defenses, and actually become less healthy.
In the same vein, maybe by sleeping on mattresses indoors all the time, we fail to build a tolerance to adverse sleeping conditions, and maybe get more sensitive to them too.
I knew of an old thai man who's face looked like he was 80 and his body looked cut and jacked. He also preferred to sleep with a thin mat on a hard tile floor with his wife in a house where there were multiple clean, usable beds to easily sleep on instead.
So if your body adjusts to it, it's definitely possible to actually prefer it.
So if your body adjusts to it, it's definitely possible to actually prefer it.
Hard perfectly flat sleeping surfaces with just a simple blanket for warmth can stimulate the lymphatic system much like a massage can.
The worst is when you have an uneven surface, like when camping and there is a rock which even your (inflatable) roll mat cant dampen out, that makes sleep difficult.
The worst is when you have an uneven surface, like when camping and there is a rock which even your (inflatable) roll mat cant dampen out, that makes sleep difficult.
My anecdote is that when I get migraine headaches, I have to lay down and try to sleep. I have to lay on hard ground. I can't stand being on a mattress for some reason. Maybe it's about feeling more control over the position of my body.
To me there is something deeply comforting about inertness. I hate the springyness in matresses so much I got a natural latex mattress, which I found out most people get because of allergies, but to me its like a kinetic sensory deprivation chamber- just absorbs all movement and doesn’t reflect it back.
Okay, and the sensory deprivation helps you sleep? I suppose that's generally what we're headed for. Turn off the lights. Set the temp to a certain level.
The hard ground isn't giving either, but you feel it. ;)
I also can't deal with pillows when I have a migraine. Though I can't sleep without something under my head. I usually just roll up a towel or something. As I said before, I think it's about having precise control over body position.
The hard ground isn't giving either, but you feel it. ;)
I also can't deal with pillows when I have a migraine. Though I can't sleep without something under my head. I usually just roll up a towel or something. As I said before, I think it's about having precise control over body position.
Like OP, some of the best nights of sleep I've had in my life have been while camping (in good weather, mind you). Different strokes maybe.
Hunter gatherers thriving on 5-7 hours aren't sleeping on modern mattresses either.
Hunter gatherers thriving on 5-7 hours aren't sleeping on modern mattresses either.
Yes.
I would love to hear more about the survival situations you did (I'm guessing intentionally) - and about the bear skins!
Not much to say there, sadly (fortunately?). I grew up north surrounded by forests and had classes. Then as a kid up until young adulthood, gathering with friends and going into the woods with minimal equipment for the weekend was the easiest way to have freedom away from the parents.
As for the skins, I have only slept on a bear's because it was at someone's cabin. Even if the place didn't have much in term of heating it was still a good night. Sleeping on the skin wasn't planned but it happened due to comfort. A friend had a beaver's and a wolf's but those are too small to sleep with unless crafted into something bigger. They did keep your knees warm however!
As for the skins, I have only slept on a bear's because it was at someone's cabin. Even if the place didn't have much in term of heating it was still a good night. Sleeping on the skin wasn't planned but it happened due to comfort. A friend had a beaver's and a wolf's but those are too small to sleep with unless crafted into something bigger. They did keep your knees warm however!
The whole “natural” thing is maybe a good source of ideas to try, but that’s it.
A list of things that are totally unnatural: brushing teeth, antibiotics, painkillers, surgery, hip replacements, antidepressants, infant mortality below 10%, not dying of an ear infection, clean chlorinated water...
A list of things that are totally unnatural: brushing teeth, antibiotics, painkillers, surgery, hip replacements, antidepressants, infant mortality below 10%, not dying of an ear infection, clean chlorinated water...
For the readers, here's my actual argument (https://guzey.com/theses-on-sleep/#comfortable-modern-sleep-...):
>1. Experiencing hunger is normal and does not necessarily imply that you are not eating enough. Never being hungry means you are probably eating too much.
>2. Experiencing sleepiness is normal and does not necessarily imply that you are undersleeping. Never being sleepy means you are probably sleeping too much.
>1. Experiencing hunger is normal and does not necessarily imply that you are not eating enough. Never being hungry means you are probably eating too much.
>2. Experiencing sleepiness is normal and does not necessarily imply that you are undersleeping. Never being sleepy means you are probably sleeping too much.
And here's an excerpt where you repeatedly say that modern sleep is unnatural.
> Modern sleep, in its infinite comfort, is an unnatural superstimulus that overwhelms our brains with pleasure and comfort (note: I’m not saying that it’s bad, simply that being in bed today is much more pleasurable than being in “bed” in the past.)
> Think about sleep 10,000 years ago. You sleep in a cave, in a hut, or under the sky, with predators and enemy tribes roaming around. You are on a wooden floor, on an animal’s skin, or on the ground. The temperature will probably drop 5-10°C overnight, meaning that if you were comfortable when you were falling asleep, you are going to be freezing when you wake up. Finally, there’s moon shining right at you and all kinds of sounds coming from the forest around you.
> In contrast, today: you sleep on your super-comfortable machine-crafted foam of the exact right firmness for you. You are completely safe in your home, protected by thick walls and doors. Your room’s temperature stays roughly constant, ensuring that you stay warm and comfy throughout the night. Finally, you are in a light and sound-insulated environment of your house. And if there’s any kind of disturbance you have eye masks and earplugs.
> Does this sound “natural”?
> Modern sleep, in its infinite comfort, is an unnatural superstimulus that overwhelms our brains with pleasure and comfort (note: I’m not saying that it’s bad, simply that being in bed today is much more pleasurable than being in “bed” in the past.)
> Think about sleep 10,000 years ago. You sleep in a cave, in a hut, or under the sky, with predators and enemy tribes roaming around. You are on a wooden floor, on an animal’s skin, or on the ground. The temperature will probably drop 5-10°C overnight, meaning that if you were comfortable when you were falling asleep, you are going to be freezing when you wake up. Finally, there’s moon shining right at you and all kinds of sounds coming from the forest around you.
> In contrast, today: you sleep on your super-comfortable machine-crafted foam of the exact right firmness for you. You are completely safe in your home, protected by thick walls and doors. Your room’s temperature stays roughly constant, ensuring that you stay warm and comfy throughout the night. Finally, you are in a light and sound-insulated environment of your house. And if there’s any kind of disturbance you have eye masks and earplugs.
> Does this sound “natural”?
Ouch. Ambient sounds of the forest are a lot better than the modern equivalent of loud neighbors and drilling. He also seems to have forgotten that humans built fires. Caves have great sound insulation and I'm pretty sure our ancestors knew how to choose their caves.
I have spent years being a sleep deprived student because the dorms were super noisy with random parties and paper thin walls so I really can't relate to the implied utter comfortable sleeping habits of modern people. I'm sure there are people complaining about noise pollution in NY as well.
No one in my circle sleeps on an overpriced mattress. Mostly it's just the bed the place that we rent has. I never could connect with articles implying modern people live in these utterly comfortable utopias when it's really not the case. People are depressed. Especially males are doing horribly.
I have spent years being a sleep deprived student because the dorms were super noisy with random parties and paper thin walls so I really can't relate to the implied utter comfortable sleeping habits of modern people. I'm sure there are people complaining about noise pollution in NY as well.
No one in my circle sleeps on an overpriced mattress. Mostly it's just the bed the place that we rent has. I never could connect with articles implying modern people live in these utterly comfortable utopias when it's really not the case. People are depressed. Especially males are doing horribly.
A few years ago I bought a mattress for less than $100 from Amazon to sleep on.
While it was funny to complain about how uncomfortable this cheap mattress was, it was still an extremely luxurious piece of technology unfathomable to any cave dweller.
It doesn't seem so crazy to me to wonder whether modern mattresses like these are incentivizing us to sleep longer than what is optimal.
While it was funny to complain about how uncomfortable this cheap mattress was, it was still an extremely luxurious piece of technology unfathomable to any cave dweller.
It doesn't seem so crazy to me to wonder whether modern mattresses like these are incentivizing us to sleep longer than what is optimal.
People have research modern pre-industrial societies and while they do have fires and nicer sounds than drilling they don't sleep in caves. Also birds are really loud sometimes.
I don't think you'd want to sleep in their circumstances over yours, but maybe you would. I for one like camping quite a bit even though I do usually get much less sleep while camping because I'll stay up late around a fire and then wake up at sunrise. I'm sure that'd change if I were out in the woods for more than a week.
Also, maybe your not-utterly-comfortable utopia is making people, maybe especially males, depressed!
I don't think you'd want to sleep in their circumstances over yours, but maybe you would. I for one like camping quite a bit even though I do usually get much less sleep while camping because I'll stay up late around a fire and then wake up at sunrise. I'm sure that'd change if I were out in the woods for more than a week.
Also, maybe your not-utterly-comfortable utopia is making people, maybe especially males, depressed!
Yep, and here's conclusion of this argument:
>Now, what if the only sleep available to you was modern sleep?
> 1. If you don’t sleep at all, you go crazy, because some amount of sleep is necessary.
> 2. If you sleep just enough to be awake during the day, you’ll be dreaming of getting a nap at the sight of a bed and will be distracted and sleepy all the time. Importantly, I claim, in this situation, the feeling of sleepiness does not mean that you should sleep more – it’s your brain being overpowered by a superstimulus while being bored.
3. I claim that if you sleep as much as you want, you’ll probably sleep too much and become more susceptible to depression. [by analogy to eating too much]
- And if you sleep way too much at once, you’ll be feeling terrible afterwards, however pleasant the sleep was.
>Now, what if the only sleep available to you was modern sleep?
> 1. If you don’t sleep at all, you go crazy, because some amount of sleep is necessary.
> 2. If you sleep just enough to be awake during the day, you’ll be dreaming of getting a nap at the sight of a bed and will be distracted and sleepy all the time. Importantly, I claim, in this situation, the feeling of sleepiness does not mean that you should sleep more – it’s your brain being overpowered by a superstimulus while being bored.
3. I claim that if you sleep as much as you want, you’ll probably sleep too much and become more susceptible to depression. [by analogy to eating too much]
- And if you sleep way too much at once, you’ll be feeling terrible afterwards, however pleasant the sleep was.
You may attempt to apply the same analogy to drinking water, and see that it doesn't work.
If you drink as much as you want, then you'll probably drink too much (with whatever negative consequences arising as a result).
But, except for some extreme circumstances, I don't think people drink much more than is necessary to quench their thirst.
That is your conclusion might still be correct, but it doesn't follow from the analogy with eating.
That is your conclusion might still be correct, but it doesn't follow from the analogy with eating.
The thing is, the experience of drinking water has not changed much compared to before. However, if you take all beverages, you'll see that lots of people drink too much soda, and it's not to quench their thirst.
Water has changed dramatically. Think of all that goes into modern sedimentation, filtration, and disinfection - not to mention treatments for hard water or additives like fluorine. The taste is better because of the mineral content, and we can even add carbonation!
That still doesn't make it a superstimulus. The difference is not that big in terms of stimulation.
Is drinking modern water a superstimulus like modern junk food from my analogy is?
You are conditioned to overeat because your body can store the excess energy in the event of future needs.
The body is expecting such a future need as in our past there were often periods of food scarcity. Since in our modern society this food scarcity doesn't exist, the body overconsumes, preparing for a future that will never come.
We do not have such a mechanism for storing infinite water, so we do not crave an overabundance of water.
I think you are thinking about sleep on the wrong axis. It is not whether it is a superstimulus; it is whether your body can store an abundance of it for a future anticipated need.
I would argue in this case, sleep is much more like water than food in this way in that there is a very small amount of sleep (possibly zero) your body can effectively stockpile.
The body is expecting such a future need as in our past there were often periods of food scarcity. Since in our modern society this food scarcity doesn't exist, the body overconsumes, preparing for a future that will never come.
We do not have such a mechanism for storing infinite water, so we do not crave an overabundance of water.
I think you are thinking about sleep on the wrong axis. It is not whether it is a superstimulus; it is whether your body can store an abundance of it for a future anticipated need.
I would argue in this case, sleep is much more like water than food in this way in that there is a very small amount of sleep (possibly zero) your body can effectively stockpile.
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Why is sleep a superstimulus but water isn't?
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Is there any way to not experience sleepiness or hunger? Do overweight people never experience hunger?
The opposite is generally more true, where the inability to feel satiety or feeling constant hunger will be the main factor in some of the problems that cause overweight.
I feel like a bunch of the points on this list actually have an analog in Guzey's argument? Brushing teeth, for example - we do it to have a "clean" mouth, but a lot of people use mouthwash until the bacterial environment in their mouth is a barren wasteland, which is also unhealthy. Moderation is good.
Antibiotics are the same - they can also kill the flora in our intestines, and they can also lead to the creation of much more deadly microbes. Moderation is good.
Painkillers - Literally an opioid epidemic in the US right, not to mention all of the people taking OTC pain medication rather than addressing the cause of the pain, be it an underlying injury or lack of physical fitness, etc. The pain medication allows them to ignore a problem in a way that ultimately makes it worse. Moderation is good.
Harder to find analogs for the other things, and obviously I think all of these things are good on net, but just like food, excessive consumption isn't necessarily good.
Antibiotics are the same - they can also kill the flora in our intestines, and they can also lead to the creation of much more deadly microbes. Moderation is good.
Painkillers - Literally an opioid epidemic in the US right, not to mention all of the people taking OTC pain medication rather than addressing the cause of the pain, be it an underlying injury or lack of physical fitness, etc. The pain medication allows them to ignore a problem in a way that ultimately makes it worse. Moderation is good.
Harder to find analogs for the other things, and obviously I think all of these things are good on net, but just like food, excessive consumption isn't necessarily good.
Right, agreed. Moderation is good.
I’m just saying, just being “natural” is not sufficient for something to be good. It may be, and perhaps as we overstreamline our lives, we discard some good natural things, but I’m not throwing away my toothbrush just yet.
I’m just saying, just being “natural” is not sufficient for something to be good. It may be, and perhaps as we overstreamline our lives, we discard some good natural things, but I’m not throwing away my toothbrush just yet.
Natural things: arsenic, uranium, viruses, tetanus, polio, eye-eating fungus, tornado, earthquakes, volcano eruptions.
The Mother Nature's goodness.
The Mother Nature's goodness.
> My sleep statistics tells me that I slept an average of 5:25 hours over the last 7 days, 5:49 hours over the last 30 days, and 5:57 over the last 180 days hours, meaning that I’m awake for 18 hours per day instead of 16.5 hours. I usually sleep 5.5-6 hours during the night and take a nap a few times a week when sleepy during the day.
> This means that I’m gaining 33 days of life every year. 1 more year of life every 11 years. 5 more years of life every 55 years.
> Why are people not all over this?
Because that's not how humans work. You're gaining 33 days of being not-asleep in sum per year. More accurately, you're getting however many more minutes per wakeful period. And gaining minutes of being not-asleep per day is very different from "gaining days of life every year". Life != being awake. Things are happening during sleep. Useful things.
Personally, I spent many years doing what you're recommending when I was younger. Felt low-level sleepy all the time. Used caffeine off-and-on to blunt the effect. Now I've gotten into a good enough homeostasis that I don't need alarms and I don't oversleep. I never feel sleepy except for the moments before falling asleep at night or on the rare occasions where I have to wake up early. I love sleep now. I protect it and it protects me.
The quality of a day depends on how it was spent. The quality of a life is the summation of all those days. Adding 30 minutes to each day's wakeful period is not some huge gain in efficiency like you're making it out to be. And for me, gaining thirty more minutes actually makes the quality of the rest of the minutes in that day worse. I low-key despise society for making me think I needed to do more such that sacrificing my sleep and normal alertness for more time spent awake was a good trade.
I recommend looking into the concept of healthspan. Optimize for area under the curve, not time spent awake.
> This means that I’m gaining 33 days of life every year. 1 more year of life every 11 years. 5 more years of life every 55 years.
> Why are people not all over this?
Because that's not how humans work. You're gaining 33 days of being not-asleep in sum per year. More accurately, you're getting however many more minutes per wakeful period. And gaining minutes of being not-asleep per day is very different from "gaining days of life every year". Life != being awake. Things are happening during sleep. Useful things.
Personally, I spent many years doing what you're recommending when I was younger. Felt low-level sleepy all the time. Used caffeine off-and-on to blunt the effect. Now I've gotten into a good enough homeostasis that I don't need alarms and I don't oversleep. I never feel sleepy except for the moments before falling asleep at night or on the rare occasions where I have to wake up early. I love sleep now. I protect it and it protects me.
The quality of a day depends on how it was spent. The quality of a life is the summation of all those days. Adding 30 minutes to each day's wakeful period is not some huge gain in efficiency like you're making it out to be. And for me, gaining thirty more minutes actually makes the quality of the rest of the minutes in that day worse. I low-key despise society for making me think I needed to do more such that sacrificing my sleep and normal alertness for more time spent awake was a good trade.
I recommend looking into the concept of healthspan. Optimize for area under the curve, not time spent awake.
So what you are saying is that, just like me, in your 20s you were optimize for getting shit done and now, being older, you optimize for feeling good and don't care about doing as much and think that optimizing for doing earlier was a mistake for you. This is reasonable!
No. I am able to do much more now, now that I respect the signals my body is sending. Sometimes I have to force things, reality demands it, but generally I work with my body on any given day, not against it. The increase quality and amount of work is undeniable, generally and on average.
I can only imagine how much more capable I would be if I had had a better relationship with sleep and my body in general when I was younger, so the benefits of those behaviors could have compounded over a longer time frame.
I can only imagine how much more capable I would be if I had had a better relationship with sleep and my body in general when I was younger, so the benefits of those behaviors could have compounded over a longer time frame.
Do not spend time reading it. From the article:
"I have no trust in sleep scientists
Why do I bother with all of this theorizing? Why do I think I can discover something about sleep that thousands of them couldn’t discover over many decades?
The reason is that I have approximately 0 trust in the integrity of the field of sleep science."
By the way, he criticizes the book: "Why we sleep". Sure the book exaggerates, but it shouldn't be completely disqualified. BTW, if you like this book, you will probably like Oracle of the Night: https://www.theguardian.com/books/2022/jan/07/the-oracle-of-...
"I have no trust in sleep scientists
Why do I bother with all of this theorizing? Why do I think I can discover something about sleep that thousands of them couldn’t discover over many decades?
The reason is that I have approximately 0 trust in the integrity of the field of sleep science."
By the way, he criticizes the book: "Why we sleep". Sure the book exaggerates, but it shouldn't be completely disqualified. BTW, if you like this book, you will probably like Oracle of the Night: https://www.theguardian.com/books/2022/jan/07/the-oracle-of-...
Just a nitpick. In your quote it looks like the author is writing "I have no trust in sleep scientists [because] I have approximately 0 trust in the integrity of the field of sleep science".
However, the first "I have no trust in sleep scientists" is a heading, which makes the rest sound less ridiculous - the "because" part simply comes after the part you quoted.
However, the first "I have no trust in sleep scientists" is a heading, which makes the rest sound less ridiculous - the "because" part simply comes after the part you quoted.
For those interested, here's my critique of sleep science (https://guzey.com/theses-on-sleep/#our-priors-about-sleep-re...):
>Do you believe in power-posing? In ego depletion? In hungry judges and brain training? [1]
>If the answer is no, then your priors for our knowledge about sleep should be weak because “sleep science” is mostly just rebranded cognitive psychology, with the vast majority of it being small-n, not pre-registered, p-hacked experiments.
>I have been able to find exactly one pre-registered experiment of the impact of prolonged sleep deprivation on cognition. It was published by economists from Harvard and MIT in 2020 and its pre-registered analysis found null effects of sleep on all variables of interest [2] (the authors changed analysis post-hoc and fished out some significant effects. Notably, they put the post-hoc results into the abstract but decided not to mention the null-preregistered results there or anywhere else in the paper explicitly).
>So why has sleep research not been facing a severe replication crisis, similar to psychology?
>First, compared to psychology, where you just have people fill out questionnaires, sleep research is slow, relatively expensive, and requires specialized equipment (e.g. EEG, actigraphs). So skeptical outsiders go for easier targets (like social psychology) while the insiders keep doing the same shoddy experiments because they need to keep their careers going somehow.
>Second, imagine if sleep researchers had conclusively shown that sleep is not important for memory, health, etc. – would they get any funding? No. Their jobs are literally predicated on convincing the NIH and other grantmakers that sleep is important. As Patrick McKenzie notes [3], “If you want a problem solved make it someone’s project. If you want it managed make it someone’s job.”
>Even in medicine, without pre-registered RCTs truth is extremely difficult to come by, with more than one half [4] of high-impact cancer papers failing to be replicated, and with one half of RCTs without pre-registration of positive outcomes being spun [5] by researchers as providing benefit when there’s none. And this is in medicine, which is infinitely more consequential and rigorous than psychology.
And here's my critique of Why We Sleep, which the author of the comment above decided to omit for some reason:
>Here are just a few of biggest issues (there were many more) with the book.
>1. Walker wrote: “Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer”, despite there being no evidence that cancer in general and sleep are related. There are obviously no RCTs on this, and, in fact, there’s not even a correlation between general cancer risk and sleep duration. [6]
>2. Walker falsified a graph from an academic study in the book. [7]
>3. Walker outright fakes data to support his “sleep epidemic” argument. The data on sleep duration Walker presents on the graph below simply does not exist [8]
[1] https://www.gleech.org/psych
[2] https://economics.mit.edu/files/16994
[3] https://twitter.com/patio11/status/1223695673742151680
[4] https://www.science.org/content/article/more-half-high-impac...
[5] https://journals.plos.org/plosone/article?id=10.1371/journal...
[6] https://guzey.com/books/why-we-sleep/#also-no----sleeping-le...
[7] https://guzey.com/books/why-we-sleep/#appendix-what-do-you-d...
[8] https://guzey.com/books/why-we-sleep/#ok-even-if-the-who-nev...
>Do you believe in power-posing? In ego depletion? In hungry judges and brain training? [1]
>If the answer is no, then your priors for our knowledge about sleep should be weak because “sleep science” is mostly just rebranded cognitive psychology, with the vast majority of it being small-n, not pre-registered, p-hacked experiments.
>I have been able to find exactly one pre-registered experiment of the impact of prolonged sleep deprivation on cognition. It was published by economists from Harvard and MIT in 2020 and its pre-registered analysis found null effects of sleep on all variables of interest [2] (the authors changed analysis post-hoc and fished out some significant effects. Notably, they put the post-hoc results into the abstract but decided not to mention the null-preregistered results there or anywhere else in the paper explicitly).
>So why has sleep research not been facing a severe replication crisis, similar to psychology?
>First, compared to psychology, where you just have people fill out questionnaires, sleep research is slow, relatively expensive, and requires specialized equipment (e.g. EEG, actigraphs). So skeptical outsiders go for easier targets (like social psychology) while the insiders keep doing the same shoddy experiments because they need to keep their careers going somehow.
>Second, imagine if sleep researchers had conclusively shown that sleep is not important for memory, health, etc. – would they get any funding? No. Their jobs are literally predicated on convincing the NIH and other grantmakers that sleep is important. As Patrick McKenzie notes [3], “If you want a problem solved make it someone’s project. If you want it managed make it someone’s job.”
>Even in medicine, without pre-registered RCTs truth is extremely difficult to come by, with more than one half [4] of high-impact cancer papers failing to be replicated, and with one half of RCTs without pre-registration of positive outcomes being spun [5] by researchers as providing benefit when there’s none. And this is in medicine, which is infinitely more consequential and rigorous than psychology.
And here's my critique of Why We Sleep, which the author of the comment above decided to omit for some reason:
>Here are just a few of biggest issues (there were many more) with the book.
>1. Walker wrote: “Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer”, despite there being no evidence that cancer in general and sleep are related. There are obviously no RCTs on this, and, in fact, there’s not even a correlation between general cancer risk and sleep duration. [6]
>2. Walker falsified a graph from an academic study in the book. [7]
>3. Walker outright fakes data to support his “sleep epidemic” argument. The data on sleep duration Walker presents on the graph below simply does not exist [8]
[1] https://www.gleech.org/psych
[2] https://economics.mit.edu/files/16994
[3] https://twitter.com/patio11/status/1223695673742151680
[4] https://www.science.org/content/article/more-half-high-impac...
[5] https://journals.plos.org/plosone/article?id=10.1371/journal...
[6] https://guzey.com/books/why-we-sleep/#also-no----sleeping-le...
[7] https://guzey.com/books/why-we-sleep/#appendix-what-do-you-d...
[8] https://guzey.com/books/why-we-sleep/#ok-even-if-the-who-nev...
funny, this makes me even more desirous to read it
This essay, convinced me that people with no domain specific knowledge can cherry-pick ideas to support any BS they want
Here is another one of Alexey’s essays that might convince you that people with tons of domain-specific knowledge (and credentials too!) can also cherry-pick ideas to support any BS they want.
https://guzey.com/books/why-we-sleep/
Matthew Walker's "Why We Sleep" Is Riddled with Scientific and Factual Errors
https://guzey.com/books/why-we-sleep/
Matthew Walker's "Why We Sleep" Is Riddled with Scientific and Factual Errors
https://twitter.com/alexeyguzey/status/1490664815039234051
I think the author has been pretty forthright in seeking critiques from professional sleep researchers and neuroscientists.
I think the author has been pretty forthright in seeking critiques from professional sleep researchers and neuroscientists.
I will post random theories about the nature of the universe and I'll tweet that I'm expecting critiques from physicists about my theory.
Damn, should look good on a resume.
Damn, should look good on a resume.
Hilarious. Except for the fact that a bunch of neuroscientists actually read my draft and gave me comments a lot of which I incorporated in the essay, e.g. https://guzey.com/theses-on-sleep/#appendix-philipp-streiche...
People with domain specific knowledge do it just as often. It's a human condition.
Did we read different articles?
> I have been able to find exactly one pre-registered experiment of the impact of prolonged sleep deprivation on cognition. It was published by economists from Harvard and MIT in 2020 and its pre-registered analysis found null effects of sleep on all variables of interest Bessone P, Rao G, Schilbach F, Schofield H, Toma M. The economic consequences of increasing sleep among the urban poor. The Quarterly Journal of Economics. 2021 Aug;136(3):1887-941.(the authors changed analysis post-hoc and fished out some significant effects. Notably, they put the post-hoc results into the abstract but decided not to mention the null-preregistered results there or anywhere else in the paper explicitly ).
This is the highest quality of research from the most fancied universities, and it was pre-registered (the gold standard of oversight). And even they were dishonest with the results. For me, personally, this single paragraph is enough to shut the door on all (all) psychology research.
This is the highest quality of research from the most fancied universities, and it was pre-registered (the gold standard of oversight). And even they were dishonest with the results. For me, personally, this single paragraph is enough to shut the door on all (all) psychology research.
If it was published by economists, in an economics journal, doesn't that suggest you're condemning the wrong field?
I like that this challenges some assumptions, but it does very little to discredit the AMPLE research in the area. Other than to say, let's not trust old research, which is kind of a gas-lighty way to look at it.
I'm curious - what do you believe I should've done? How do you discredit a p-hacked small-n experiment, aside from noting that it should not be trusted a priori due to the extreme bias of the results expected from such kind of studies?
Is all sleep science based p-hacked small-n experiments?
To your point - I probably would have tried to rely on research that supports your points (which you've got me interested in now). I probably wouldn't have included a handful of anecdotes in the the appendix (including your own and Elon Musk's!), as well as 8 replies from a reddit thread as a supporting section. I probably also wouldn't equate "a person with an ADRB1 mutation can sleep less" and "a single individual that underwent brain surgery can sleep less" with "Decreasing sleep by 1-2 hours a night in the long-term has no negative health effects". I wouldn't include any arguments that say modern sleep is "unnatural", which doesn't have any real meaning or basis in reality (is modern medicine natural? what about sanitation?). The analogy to hunger is a justification rather than any type of proof, and taking the analogy further, it would suggest I should go back to sleep in the morning since I usually wake up sleepy, just as I would eat more when I'm hungry. I would be careful about saying sleep duration is a cause of depression/mania rather than considering both might be driven by a confounding variable (stimulants will certainly cause both mania and wakefulness!). I also probably wouldn't make claims like:
> Convincing a million 20-year-olds to sleep an unnecessary hour a day is equivalent, in terms of their hours of wakefulness, to killing 62,500 of them.
Without considering that you might be wrong about lifespan (not to mention healthspan) since you might very well be convincing others to effect a behavior change with your post.
To your point - I probably would have tried to rely on research that supports your points (which you've got me interested in now). I probably wouldn't have included a handful of anecdotes in the the appendix (including your own and Elon Musk's!), as well as 8 replies from a reddit thread as a supporting section. I probably also wouldn't equate "a person with an ADRB1 mutation can sleep less" and "a single individual that underwent brain surgery can sleep less" with "Decreasing sleep by 1-2 hours a night in the long-term has no negative health effects". I wouldn't include any arguments that say modern sleep is "unnatural", which doesn't have any real meaning or basis in reality (is modern medicine natural? what about sanitation?). The analogy to hunger is a justification rather than any type of proof, and taking the analogy further, it would suggest I should go back to sleep in the morning since I usually wake up sleepy, just as I would eat more when I'm hungry. I would be careful about saying sleep duration is a cause of depression/mania rather than considering both might be driven by a confounding variable (stimulants will certainly cause both mania and wakefulness!). I also probably wouldn't make claims like:
> Convincing a million 20-year-olds to sleep an unnecessary hour a day is equivalent, in terms of their hours of wakefulness, to killing 62,500 of them.
Without considering that you might be wrong about lifespan (not to mention healthspan) since you might very well be convincing others to effect a behavior change with your post.
>I probably also wouldn't equate "a person with an ADRB1 mutation can sleep less" and "a single individual that underwent brain surgery can sleep less" with "Decreasing sleep by 1-2 hours a night in the long-term has no negative health effects".
I made 5 points in that section (https://guzey.com/theses-on-sleep/#decreasing-sleep-by-1-2-h...):
> 1. A sleep researcher who trains sailors to sleep efficiently in order to maximize their race performance believes that 4.5-5.5 hours of sleep is fine.
> 2. 70% of 84 hunter-gatherers studied in 2013 slept less than 7 hours per day, with 46% sleeping less than 6 hours.
> 3. A single-point mutation can decrease the amount of required sleep by 2 hours, with no negative side-effects.
> 4. A brain surgery can decrease the amount of sleep required by 3 hours, with no negative-side effects.
> 5. Sleep is not required for memory consolidation.
You cited (3) and (4) but ignored (1), (2), and (5) all of which are based on studying dozens and hundreds of people.
I made 5 points in that section (https://guzey.com/theses-on-sleep/#decreasing-sleep-by-1-2-h...):
> 1. A sleep researcher who trains sailors to sleep efficiently in order to maximize their race performance believes that 4.5-5.5 hours of sleep is fine.
> 2. 70% of 84 hunter-gatherers studied in 2013 slept less than 7 hours per day, with 46% sleeping less than 6 hours.
> 3. A single-point mutation can decrease the amount of required sleep by 2 hours, with no negative side-effects.
> 4. A brain surgery can decrease the amount of sleep required by 3 hours, with no negative-side effects.
> 5. Sleep is not required for memory consolidation.
You cited (3) and (4) but ignored (1), (2), and (5) all of which are based on studying dozens and hundreds of people.
I'm not arguing you should not have included (1), (2), and (5), I'm arguing you should not have included (3) and (4) because they do not support the point of the passage.
No, you are. You specifically wrote that I "equate" (3) and (4) to my conclusion. You wrote:
>probably also wouldn't equate "a person with an ADRB1 mutation can sleep less" and "a single individual that underwent brain surgery can sleep less" with "Decreasing sleep by 1-2 hours a night in the long-term has no negative health effects".
>probably also wouldn't equate "a person with an ADRB1 mutation can sleep less" and "a single individual that underwent brain surgery can sleep less" with "Decreasing sleep by 1-2 hours a night in the long-term has no negative health effects".
Yes, I am well aware of what I wrote. Let me clarify.
Your section is titled:
"Decreasing sleep by 1-2 hours a night in the long-term has no negative health effects".
You make two points below to support that claim:
- "A single-point mutation can decrease the amount of required sleep by 2 hours, with no negative side-effects."
- "A brain surgery can decrease the amount of sleep required by 3 hours, with no negative-side effects."
Those points do not support your claim, and I am pointing that out. I have no issue with the other 3 points, nor did I say anything about them.
Your section is titled:
"Decreasing sleep by 1-2 hours a night in the long-term has no negative health effects".
You make two points below to support that claim:
- "A single-point mutation can decrease the amount of required sleep by 2 hours, with no negative side-effects."
- "A brain surgery can decrease the amount of sleep required by 3 hours, with no negative-side effects."
Those points do not support your claim, and I am pointing that out. I have no issue with the other 3 points, nor did I say anything about them.
“This guy fucks”
Claims of the nature "the entire field is wrong, I propose to change everything" are deserving of a bit more basis in fact than this.
There is neither supporting evidence, nor even plausible models that go beyond the clearly superficial.
I don't know if the author is right. But Occam's Razor implies that simply ignoring this as, well, yet another person positing vague claims on the Internet, is probably the right answer.
To be fair, they did claim this to be theses. I am looking forward to them proving or disproving those theses. I will not lose much sleep until then.
There is neither supporting evidence, nor even plausible models that go beyond the clearly superficial.
I don't know if the author is right. But Occam's Razor implies that simply ignoring this as, well, yet another person positing vague claims on the Internet, is probably the right answer.
To be fair, they did claim this to be theses. I am looking forward to them proving or disproving those theses. I will not lose much sleep until then.
There's a lot, the appeal to how humans lived 10k years ago seems odd though. Just because they lived in a certain way doesn't mean it's optimal. This is plainly obvious when you look at diets. Just because something was done out of necessity doesn't mean it's right. Weak argument right off the bat.
I don't think he's using the appeal to say that the way pre-industrial people live is optimal. He's saying that maybe 7-9 hours isn't optimal.
Irrelevant to the post, but relevant to sleeping--I fixed my trouble sleeping with candles.
Right before I want to go to sleep, I darken the whole house, light one or two candles, and read a slow-paced book. 15 minutes to drowsiness, 5 minutes to sleep, every time. I'll even look at a blue-light screen right up until candle-time.
Right before I want to go to sleep, I darken the whole house, light one or two candles, and read a slow-paced book. 15 minutes to drowsiness, 5 minutes to sleep, every time. I'll even look at a blue-light screen right up until candle-time.
A friend of mine did that.
Burned her house down, killed her pets (fish), and barely survived herself.
She now recommends not leaving candles burning unattended.
There might be a battery-powered candle-like LED thing that gets the same results.
Burned her house down, killed her pets (fish), and barely survived herself.
She now recommends not leaving candles burning unattended.
There might be a battery-powered candle-like LED thing that gets the same results.
LEDs are counter productive to sleep. The solution here would be a safe candleholder that is able to be left unattended without setting fires.
If it's a dim LED with just red light or maybe just red and orange then it's probably just as good, no?
The flickering will be there no matter the color. Red ones will be better than white or blue ones, but that's it. They still have the opposite of a relaxing effect.
Flicker is a side effect of a common method of variable LED dimming. It's not intrinsic to the technology. You can run an LED at a low level with zero flicker.
But I'm thinking of the tea light replacements that are sold for use in jack-o-lanterns. They intentionally "flicker" in a candle-like way, instead of the kind of flicker you describe.
LED devices can also produce a wide range of color temperatures (esp when filtered and diffused), so there's no inherent blue light problem.
But I'm thinking of the tea light replacements that are sold for use in jack-o-lanterns. They intentionally "flicker" in a candle-like way, instead of the kind of flicker you describe.
LED devices can also produce a wide range of color temperatures (esp when filtered and diffused), so there's no inherent blue light problem.
Connect an LED directly to a battery (as in many cheap flashlights) and there will be no flicker.
The human retina will perceive flicker above 200 Hz even if you won't consciously be aware of it.
There are a lot of anecdotal stories out there where people get a reduced sleep quality after switching to LED lighting in the bedroom. Is there something deeper to the story? Quite likely. The question now would be whether this affects everyone or if those people are outliers.
There are a lot of anecdotal stories out there where people get a reduced sleep quality after switching to LED lighting in the bedroom. Is there something deeper to the story? Quite likely. The question now would be whether this affects everyone or if those people are outliers.
Oh, I blow it out before I fall asleep. Was she sleeping with candles lit?
Be aware that candles cause air pollution that can especially be an issue in homes with poor ventilation.
I can recommend a tablet set to a black background for this, sans candles.
No mention of the CO2 buildup in a bedroom or buildings in general.
When I camp in a tent, more airflow, I sleep better. In a bedroom, the air is stale after a few hours, the UK has small houses unlike Europe and US.
Plenty of discussions on CO2 levels on here already: Higher Levels of CO2 May Diminish Decision Making Performance (2013) https://news.ycombinator.com/item?id=14738010
Literally Suffocating in Meeting Rooms, A Little https://news.ycombinator.com/item?id=21237875
On whether changes in bedroom CO2 levels affect sleep quality https://news.ycombinator.com/item?id=18959796
Is Conference Room Air Making Us Dumber? https://news.ycombinator.com/item?id=19845029
No mention of Tryptophan intake, tryptophan into the brain can become serotonin and melatonin.
Blue light stimulates serotonin production in the brain, a jap study on school kids found when all things equal including diet, they found those with highest serotonin levels walked to school and got more blue light from the sun than those driven to school.
Melatonin has an antioxidant effect 4x greater than vit c, it also increase the release of mesenchymal stem cells so the body can repair itself better, which is important when thinking about plastic molecules in the body, because a study suggests plastic binds to stem cells and inactivates the cell making it harder for us to repair.
Light pollution within the bedroom from clocks, phones etc can also reduce melatonin compared to a completely blacked out bedroom.
The serotonin hypotheses about sleep duration ie little sleep mania, more sleep depression didnt look at CO2 levels.
The author needs to be careful what scientific studies are selected and ignored, sleep is massively complex, but I am also aware even google scholar doesnt always present the links to everything on a topic. Just like SEO can manipulate business website ranking, scientific study ranking can also be manipulated!
When I camp in a tent, more airflow, I sleep better. In a bedroom, the air is stale after a few hours, the UK has small houses unlike Europe and US.
Plenty of discussions on CO2 levels on here already: Higher Levels of CO2 May Diminish Decision Making Performance (2013) https://news.ycombinator.com/item?id=14738010
Literally Suffocating in Meeting Rooms, A Little https://news.ycombinator.com/item?id=21237875
On whether changes in bedroom CO2 levels affect sleep quality https://news.ycombinator.com/item?id=18959796
Is Conference Room Air Making Us Dumber? https://news.ycombinator.com/item?id=19845029
No mention of Tryptophan intake, tryptophan into the brain can become serotonin and melatonin.
Blue light stimulates serotonin production in the brain, a jap study on school kids found when all things equal including diet, they found those with highest serotonin levels walked to school and got more blue light from the sun than those driven to school.
Melatonin has an antioxidant effect 4x greater than vit c, it also increase the release of mesenchymal stem cells so the body can repair itself better, which is important when thinking about plastic molecules in the body, because a study suggests plastic binds to stem cells and inactivates the cell making it harder for us to repair.
Light pollution within the bedroom from clocks, phones etc can also reduce melatonin compared to a completely blacked out bedroom.
The serotonin hypotheses about sleep duration ie little sleep mania, more sleep depression didnt look at CO2 levels.
The author needs to be careful what scientific studies are selected and ignored, sleep is massively complex, but I am also aware even google scholar doesnt always present the links to everything on a topic. Just like SEO can manipulate business website ranking, scientific study ranking can also be manipulated!
How does your essay explain that I feel horrible for 2-3 hours after waking up if I don't get enough sleep?
I don't just mean feeling a little slow. I am physically sick to the point of being unable to eat food, having a headache (not every time) and not being able to process information (e.g. reading an email 2-3 times and still not comprehending it fully).
Is this a unique reaction?
I don't just mean feeling a little slow. I am physically sick to the point of being unable to eat food, having a headache (not every time) and not being able to process information (e.g. reading an email 2-3 times and still not comprehending it fully).
Is this a unique reaction?
> How does your essay explain that I feel horrible for 2-3 hours after waking up if I don't get enough sleep?
So, you are saying that when you don't get enough sleep, you feel fine most of the day, except for the first 2-3 hours after waking up? This is pretty weird and I don't have a good explanation for you.
So, you are saying that when you don't get enough sleep, you feel fine most of the day, except for the first 2-3 hours after waking up? This is pretty weird and I don't have a good explanation for you.
Yes, on a good day it takes me maybe 30-40 minutes to get going.
On a day when I don't get enough sleep, it takes several hours, negating whatever "time savings" there are from forgoing sleep.
On a day when I don't get enough sleep, it takes several hours, negating whatever "time savings" there are from forgoing sleep.
hey this is me too. never found a solution to it and for me I require more sleep to maximize my time because otherwise i feel terrible and am unable to function, especially in the first half of my day.
On a whole, I feel like there is another side of this coin which is that being hungry might not be bad for you, but if you're hungry enough it can be very unpleasant.
On a whole, I feel like there is another side of this coin which is that being hungry might not be bad for you, but if you're hungry enough it can be very unpleasant.
It's hard to me to even start considering whether I might be sleeping too much or whether sleeping less is not actually that bad, when the act of forcefully waking up (due to noise, alarm or whatever) is something I would classify as not too far from torture.
Does this simply not bother other people that much?
Does this simply not bother other people that much?
Yes, please, do continue to slam a whole field that you are not yourself in. Love hearing from people who love to just cherry pick a couple of articles to support their claims. eye roll
>Yes, please, do continue to slam a whole field that you are not yourself in. Love hearing from people who love to just cherry pick a couple of articles to support their claims. eye roll
I wholeheartedly agree. Similarly, people outside of astrology shouldn't be criticizing astrology.
I wholeheartedly agree. Similarly, people outside of astrology shouldn't be criticizing astrology.
Everyone is able to criticize anyone. Which is why people are criticizing your blog post.
Hey, be careful with that criticism there. I don't know that you are in the same field as ninesnines
A lot of this stuff matches my experience. I'm a classic night owl and occasionally subject myself to acute sleep deprivation (< 3-4 hours of sleep). Typically the next day I'm in weirdly good humor, slightly manic, and feel as if my senses have been heightened. My girlfriend thinks I'm crazy for saying this, but I enjoy the feeling. If the sleep deprivation turns into multiple days, I begin to become sluggish and irritable...but I try not to let that happen.
As a night owl and an introvert, there's this perverse feedback loop where I'm incentivized to be underslept before an important presentation, because the slight good humor / mania / heightened senses (and, I would add, a mild numbness to peoples' judgments about me) help me do a better job of the presentation.
Of course, I'm not advocating that people be totally loopy! But there's a weird Ballmer peak-esque [1] effect.
[1] https://xkcd.com/323/
Of course, I'm not advocating that people be totally loopy! But there's a weird Ballmer peak-esque [1] effect.
[1] https://xkcd.com/323/
Very interesting article. I'll try that myself, could be a fun experiment. The parallel with fasting was surprising to me, though now it sounds obvious. Outside of whether or not the author is right about their theory, this calls for more rigorous science on sleep. The value of even a small chance of adding 1/2 hours to the life of people is immense.
This essay convinced me to experiment with 6 hour sleep days. Excited to see what happens.
> Finally, there’s moon shining right at you and all kinds of sounds coming from the forest around you.
Tell me you've never been in a remote area without telling me you've never been in a remote area. If you go somewhere truly far from any developed city (I first experienced it in rural China) you will often find at night that it is BLACK. Can't see your hand right in front of your face BLACK. I remember someone starting a blow torch to work on a car in the middle of the night and it was like a rave the light show was so intense against how deep the darkness was.
Tell me you've never been in a remote area without telling me you've never been in a remote area. If you go somewhere truly far from any developed city (I first experienced it in rural China) you will often find at night that it is BLACK. Can't see your hand right in front of your face BLACK. I remember someone starting a blow torch to work on a car in the middle of the night and it was like a rave the light show was so intense against how deep the darkness was.
Potentially of relevance, a paper I wrote on a possible function of dreaming during REM sleep:
A Suggestion for a New Interpretation of Dreams: Dreaming Is the Inverse of Anxious Mind-Wandering
https://psyarxiv.com/k6trz
Discussed on hacker news here: https://news.ycombinator.com/item?id=19143590
A Suggestion for a New Interpretation of Dreams: Dreaming Is the Inverse of Anxious Mind-Wandering
https://psyarxiv.com/k6trz
Discussed on hacker news here: https://news.ycombinator.com/item?id=19143590
Perhaps coincidentally, but I can rarely sleep more then 6 hours in a night. It seems that I've always been that way. My eyes just open after about 6 hours, and I feel the need to get out of bed. The only way I've ever been able to get more is when I'm hungover or ill.
I don't ever feel like I need to sleep more, but the anxiety I get from all the sleep studies telling me I do need to sleep more, sure does keep me up at night!
I don't ever feel like I need to sleep more, but the anxiety I get from all the sleep studies telling me I do need to sleep more, sure does keep me up at night!
I wonder if you have either of the known genetic mutations related to a shorter sleep duration. I understand it's pretty rare, but some percentage of the population have them and you might be one of the lucky few!
Do you feel fully rested after 6 hours?
Yes. In fact, I can't even nap most of the time, and I can easily stay up past my "standard" bedtime, if I'm not careful. I've even moved my run to second-thing-in-the-morning, to see if I became more tired in the evenings, but it doesn't make a difference.
> Modern sleep, in its infinite comfort, is an unnatural superstimulus that overwhelms our brains with pleasure and comfort
Would you expect this to generalize to other animals? For example, if you gave ultra-comfortable beds to dogs, mice, etc., would you expect them to spend longer times asleep? And I think we should specify "asleep, not merely resting" here.
Would you expect this to generalize to other animals? For example, if you gave ultra-comfortable beds to dogs, mice, etc., would you expect them to spend longer times asleep? And I think we should specify "asleep, not merely resting" here.
This is an interesting question.
Though it's not really an answer to that specific question, Jerome Siegel in one paper says: "although animals in the wild are usually healthier that those confined to laboratories and zoos, animals in the wild often have less sleep that those in zoos. Sloths in the lab average 15 h/day of sleep, but they sleep 9 h/day in the wild. Frigate birds in cages sleep 9.3 h, but when flying over the ocean for 10 day periods they sleep 0.7 h/day, without rebound. Fur seals have 80 min of REM sleep/day on land, but in water, where they spend >70% of their life, they average 3 min of REM a day. They have no REM “rebound” when they return to land."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8180237/pdf/nih...
We need to put soft mattresses out in nature and document what happens.
Though it's not really an answer to that specific question, Jerome Siegel in one paper says: "although animals in the wild are usually healthier that those confined to laboratories and zoos, animals in the wild often have less sleep that those in zoos. Sloths in the lab average 15 h/day of sleep, but they sleep 9 h/day in the wild. Frigate birds in cages sleep 9.3 h, but when flying over the ocean for 10 day periods they sleep 0.7 h/day, without rebound. Fur seals have 80 min of REM sleep/day on land, but in water, where they spend >70% of their life, they average 3 min of REM a day. They have no REM “rebound” when they return to land."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8180237/pdf/nih...
We need to put soft mattresses out in nature and document what happens.
Crackpot garbage.
Sleep fasting? Maybe occasional fasting in everything can be good.
Food, sex, sleep, social interactions.
I would argue that some of my best nights were during outdoor survival situations where I slept in small shelters that kept my warmth and on a hard surface.
Personally, the sound of a familiar bird species will lull me to sleep. Birds sing when it's safe. Silence in nature is when you should worry.
Having slept on bear skins, those are surprisingly comfortable. That's why it's such a trope in romance. You can easily fall asleep on one and be comfortable all night. Throw in a few friends and you have got a cozy experience. Three people will keep a bed very warm even without heating to the point where you must open windows and get rid of covers.
Have we forgotten that our species has used fire as a tool for at least 2 million years? Usually, a fire would be kept going all night which would keep the camping ground dry and warm.
Has the author ever slept in the wild? Birds waking you? If this held true, no one would be able to sleep in rural areas.
This thesis seems to extrapolate a lot without paying attention to the details. It presents ideas as common sense and proceeds to mislead the reader through cherry-picked information that is a prime example of the confirmation bias.