The awake ape: Why people sleep less than their primate relatives | Hacker News Reader

The awake ape: Why people sleep less than their primate relatives

knowablemagazine.org

I read the whole article and I still don’t know why people sleep less. They mention stress and out of whack circadian rhythm which can mean many things.

I think we do it to ourselves. More and more people are sleeping less than ideal sleep or have chronic sleep issues. We pump our systems full of caffeine and alcohol and our body hardly knows how to process it for actual sleep. We sit on bright blue screens until minutes before we think we can sleep. We hear noises indicating the start and end of a workday. We have artificial lights all throughout our homes and bedrooms where we sleep. We aren’t regularly told by anyone but our guardians that sleep is important in the long term and if we don’t work on good sleep habits today, we’ll suffer as we age.

While wild animals and early human just have to worry about predators, that seems like social sleeping has deterred this problem for millennia.

The very first sentence of the article disproves your claims.

It has nothing to do with caffeine, blue screens, or artificial lights.

It's the first sentence!!

"On dry nights, the San hunter-gatherers of Namibia often sleep under the stars. They have no electric lights or new Netflix releases keeping them awake. Yet when they rise in the morning, they haven’t gotten any more hours of sleep than a typical Western city-dweller who stayed up doom-scrolling on their smartphone."

That still doesn't explain why people sleep less.

Yes it does. Modern humans have so many more things to do than hunter gatherers or monkeys. Monkeys can't engage in cocaine fueled raves til 6am, work the night shift at a nuclear plant, or pull an all-nighter to pass their organic chemistry mid term. They can't stay awake till 4am watching anime.

Which of those things is done by “San hunter-gatherers of Namibia” when they sleep under the stars?

While there’s an argument about hours, there’s also quality of sleep. Especially REM and Non-REM. It’s still a very interesting comparison.

This can explain (it’s inside the article):

> Humans, then, seem to have evolved to need less sleep than our primate relatives. Samson showed in a 2018 analysis that we did this by lopping off non-REM time.

But is still an hypothesis.

This would explain how, but not why.

Why it's simple: evolution! Because if you sleep less you have more time when you're vulnerable to enemies, more time to hunt for food, more time for work, etc..

I’m asking for why humans evolved in that way while other primates/mammals didn’t. One would assume that there was some sort of selective pressure.

According to the article, one idea is it's because they slept on the ground and were more vulnerable to predators. But then speculates that it could also be because people were better at using dark time more productively than other animals, thanks to story telling and fires.

If I can add my own speculation, I think we are our own predator and selection pressure. People haven't been threatened by nature for a very long time, but we are threatened by each other.

> We pump our systems full of caffeine and alcohol

At least these drugs are for recreation. Worse is people taking Adderall and co. Taking drugs to perform better? I am happy with performing worse then and I haven't really seen it working anyway.

Even kids free time is extremely scheduled so no wonder parents don't get sleep. Their childless counterparts don't have it much better since they are expected to work more.

But perhaps it is still the same fear as before. We believe if we don't work as much we would get left behind.

But an obvious advantage for humans needing less sleep is probably nutrition.

"bright blue screens until minutes before we think we can sleep" is hardly the case anymore, at least for the majority of those who actually spend that much time. Many desktop OS and mobile OS shipped in the past 3-4 years have built-in night light options that reduce blue hues in the display, for the exact purpose of mitigating impacts of screen usage to sleep.

Agreed. Was mostly referring to both the artificial light(of any kind) and the distractions on those devices are awful for sleep routine.

I heard those mitigating measures don't do diddly.

I heard that blue light did not do diddly.

Yup. Blue light was/is a recent fad "cure" for sleep issues. The impacts are negligible outside test centers. I have a red-light setting on my phone for 10pm. In practice it is nothing more than a silent alarm that tells me to stop watching youtube.

It feels to me like humans need darkness more than other animals to sleep. I'm curious if this another excuse rather than a real issue.

I suspect darkness works, but only because it mitigates circadian rhythm issues somewhere else.

I fall asleep easier with an eye mask on (and sometimes can't without it), but also feel like I dream more without it, and no dream sleep isn't as mentally refreshing.

I do have some sleep stage measuring gadgets to actually test this, but sleeping with an EEG headband on isn't the most comfortable thing.

You clearly haven't sat in front of bright blue light when you were feeling sleepy. I have a SAD light, and it's about as good as a coffee at waking me up.

It’s the brightness though, not the blueness, apparently.

There are various studies in which they measure the amount of melatonin in subjects' saliva, after exposing them to different wavelengths of light at the same ... well, in this case it's energy rather than lux: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.96...

> Two long wavelengths, 595 nm (amber) and 660 nm (red) and three shorter wavelengths, 470 nm (blue), 497 nm (blue/green), and 525 nm (green) were compared with a no-light control condition. Light was administered via a portable light source comprising two light-emitting diodes per eye, with the irradiance of each diode set at 65 µW/cm 2. [...] Half-hourly saliva samples were collected on the evening prior to the first light pulse and the evening following the second light pulse. The time of melatonin onset was calculated for each night and the difference was calculated as a measure of phase advance. The shorter wavelengths of 470, 495 and 525 nm showed the greatest melatonin onset advances ranging from approximately 40–65 min while the longer wavelengths produced no significant phase advance.

Looking at a second source for lux at different wavelengths... https://www.circadiansleepdisorders.org/info/lux.php

It says light sensitivity peaks at 555 nm, and the graph looks mostly symmetrical (though the red side is slightly higher than the mirrored blue side). If it were all about perceived brightness, then I think we'd expect amber light to have a stronger effect than blue-green or blue, but that was not observed.

The 555 is the peek of the cells that provide vision.

The circadian sensor is separate from vision, it receives light that comes from top, its range goes beyond vision range into ultraviolet, its sensitivity goes up with the light frequency.

The recommendation to go for a walk outside in the morning to fix the circadian rythm is basically to get ultraviolet coming from the top to your eyes, as that is most effective. In the evening any required lighting should be dim, red and coming from bottom.

Blue light screen filters do help somewhat but the sum of the remaining lower bands still has the potentiall to mess up the circadian.

source: Andrew Huberman podcasts on sleep

My experience is that they make a big difference, but you have to set them to be quite strong in order for them to do so. So much so that for example the built in feature on mac/ios isn't strong enough even at the maximum configurable strength! However, 3rd party apps like f.lux on mac or twilight on android can set the redness much stronger at which point it really does make a difference.

If people like redshifting, that's all that matters. Quite a lot of people like it, which is why implementations of this feature have proliferated. What's the point in moaning about the lack of scientific backing? Are you trying to convince people to stop liking a thing they like? For what purpose? It's not as though there is any harm in the feature.

No one I work with uses this in the office. I am the only one and they complain that my screen "hurts their eyes" because of its orange hue.

I would not be so quick to dismiss the effects of staring into light bulbs for 8-12 hours a day.

The opener of this article references the 7 hours of sleep figure for hunter gatherers which is from a quality study using sleep tracking devices [1]. But please note that’s actual sleep: you may need to be in bed for 8-9 hours to get 7 hours of sleep. When I used the Oura ring to track sleep I realized I usually overestimated my sleep time by discounting time to fall asleep and any time from being woke up at night.

The article states:

> By contrast, a 2016 study of almost 500 people in Chicago found they spent nearly all of their time in bed actually asleep

I think this is a poor summary: when I look at the study cited, it looks like the participants are awake in bed for an average of 50 minutes.

[1] https://www.cell.com/current-biology/fulltext/S0960-9822(15)...

Anecdotally I always fall asleep within 15 mins, usually much sooner so this is an individual decision.

Same here. Usual is to be asleep within ten minutes. Easy.

Sort of along the lines of sleeping as a group, I theorize that some of the (modern) human datapoints are due to the gradual isolation of humanity combined with the sleeplessness that comes with the first few years of child rearing.

Historically, child rearing was supported by a tribe of people. Nowadays, we have isolated ourselves to the point of one or two parents and maybe a grandparent or two. Babies can take years to get to consistently sleep through the night. So we have taught ourselves to be more “self sufficient” and just deal with it.

Or maybe I just think this because my 6 month old woke up four times last night and I’m losing my mind.

I highly, highly recommend this book: https://www.amazon.com/Sleepeasy-Solution-Exhausted-Parents-...

You can probably borrow it for free at your local library, you certainly don’t need to own it.

It’s easy to follow, both of our kids were well sleep trained at 5 months. I’ve foisted it on three different friends who were struggling and they all turned it around within a week.

YMMV, all kids are different, but empirically this method seems to work best of the approaches I’ve seen tried.

This is #2 and our 3 year old sleeps through the night almost every night now!

We’ve been disruptive to the little one’s sleep so far due to some home renovations causing a lack of consistency for just about her whole life. I’m confident we will figure it out eventually.

“Or maybe I just think this because my 6 month old woke up four times last night and I’m losing my mind”

It gets better, of course - but I also lost my mind.

I had to return to work after three weeks, and I distinctly remember a moment where I thought, “I really should not be driving right now”.

I experienced something like this for a short time just trying to take care of some very young motherless kittens who needed feeding every 4 hours. I quickly got to the point where I was engaging in reckless self medicating to get through it. It really cemented my long-ago decision not to have children, while increasing my respect for those who do.

It’s self inflicted by weird British notions of how children should be reared. We had no difficulties whatsoever or sleep lost, my wife would just lay next to our baby with her shirt off and if the baby got hungry she’d eat. My wife wouldn’t even wake up. Westerners bring these tortures upon themselves.

It's probably the onset of modernism - they decided everything in life had to be lived according to logical rules they made up in their heads, rather than just doing whatever folk knowledge your parents passed on that had no rationale. The advantage is this often does work, but the disadvantage is you end up with Victorian parenting, doctors who wouldn't wash their hands because you can't explain why they should, having to eat corn flakes, world wars, etc.

We coslept and as long as you aren’t drinking alcohol or taking ambien or anything that’d impair your ability to respond to your child you won’t wake up and will feed ad libitum. We slept great with our first. Our second has a physical disability and wakes up screaming a few times a night for unknown reasons that at three she can’t elucidate but at least the first was easy. Then the hard part is getting them out of your bed when they’re older.

> Yetish describes a typical evening with the Tsimane: After spending the day working on various tasks, a group comes together around a fire while food is cooked. They share a meal, then linger by the fire in the dark. Children and mothers gradually move away to sleep, while others stay awake, talking and telling stories.

> And so Yetish suggests that ancient humans may have traded some hours of sleep for sharing information and culture around a dwindling fire. “You’ve suddenly made these darkness hours quite productive,” he says. Our ancestors may have compressed their sleep into a shorter period because they had more important things to do in the evenings than rest.

My vote is definitely for the boredom theory. I know when I stay up reading or coding or doodling every night it's not because I'm freaked out about bears or lions getting into my house (although I obviously should be) it's because my brain still needs to dive into something interesting after a long day of mundane tasks.

I also think there could be a connection to The Beginning was the End if anyone gets that creepy reference. Psychotic sleep deprived primates creating an insane society and destroying the earth. I could get behind that too.

Anyway this was a fun informative read to wake up to. Even though I probably should have just slept in an extra 20 minutes.

While interesting, such stories tell us nothing about our sleep needs. Sleep is a primordial thing. Even some basic creatures like jellyfish "sleep" on a daily cycle. So what our ancestors did around the campfire 10,000 years ago is irrelevant. Our sleep needs evolved long long before we harnessed fire. A few thousands years isn't enough time to make much of an evolutionary difference to something that began before we walked upright, even before we walked on land.

The single eight-hour, 1/3 of the day paradigm is a modern construct. In all likelihood our best sleep pattern involves multiple stints. Just ask anyone in a hot country about the advantages of siesta.

I read somewhere that Freud and psychoanalysis became an issue only after electric lighting was a thing. Before that, it was argued, people got a lot more sleep.

(In fact, in the time before artificial lighting, it was common to speak of your “first sleep“ and your “second sleep“: People essentially slept two times a night. They went to bed at sunset. Then, they woke up for an hour or two around midnight, which apparently was used, everything being dark, for sex and contemplation. And then they fell asleep for a second time, until sunrise.)

> People essentially slept two times a night. They went to bed at sunset. Then, they woke up for an hour or two around midnight, which apparently was used, everything being dark, for sex and contemplation. And then they fell asleep for a second time, until sunrise

This, as far as I can tell, was not a very universal thing, at least across cultures.

This is very plausible. It seems, for example, in India, the ideal time for morning prayer and meditation was the Brahma Muhurta, which is variously said to be between 3:30 - 6:30 am (probably dependent on the seasons and sunrise). This implies that people went to sleep around 8 pm or 9 pm, as many people in rural India still do. There is no mention of people getting up in between, in any of the traditional descriptions.

https://en.wikipedia.org/wiki/Brahmamuhurtha

If you live in a loud and brightly lit environment, I highly, highly recommend blackout curtains. They've been a revelation in terms of improving length and quality of sleep.

If blackout curtains don't work for the window, or if you're too poor (or too cheap) to buy blackout curtains, you can tape aluminum foil up over the glass and it blocks all the light. I used to do that all the time when working crazy hours in the military.

Getting an eye mask works better for me; if you have blackout curtains and forget to open them you end up living in a cave. They do keep the room a bit colder though.

As to the answer to the title of this article: the article states that the sleep numbers for primates come from captivity and that when they did a study in the wild the number was far less. So there’s not quite as much mystery here as it first seems. Humans sleep less, but not nearly as much as the numbers would suggest.

Time "asleep" is not a good enough measure of sleep. You wouldn't judge an animals diet based on how much time they spent eating. It is a poor proxy.

I have a dog in this fight, as my start-up (https://soundmind.co) is focused on improving Sleep Performance. The neurological function of your brain while you sleep.

Sleep is not only made up of distinct stages (Wake, N1-N3, REM), but even within those stages there are neurological processes such as Slow Wave Oscillations (our current focus), Sleep Spindles, K-Complexes, and more.

We also have a lot more to learn about sleep.

Only if researchers were tracking not only the stages of sleep, but also these deeper processes would we be able to fully understand how the sleep of primates (or any other animals) compares to human sleep.

I remember a while ago hearing one theory on sleep is that one common manifestation of a natural sleeping schedule is 4 hours (8 - 12), followed by being awake for 2 hours (12 - 2) and then another 4 hours (2 - 6) of sleep, for a total of 8 hours.

I've also noticed in myself often I will get tired around 8:30 or so. But I usually stay awake and then don't end up falling asleep till 2.

This is anecdotal but it seems to fit this pattern of needing to get one round of sleep in (which I blow past), being awake late, and then falling asleep from 2am - 8/9am. I suspect the 2 - 8/9 is that instead of 2-6 since I missed also the previous window.

I am surprised there's no mention of two sleeps: https://news.ycombinator.com/item?id=29886907

Not sure if this might be related but humans have a stimulants addiction that most primates generally don't. I'm surprised it wasn't mentioned by the article.

I think calling it a caffeine "addiction" is a bit misleading. Dependence is a more accurate word.

Interesting they did not list gorillas, I looked it you and seems the average 12 hours per night.

contributing factor mentioned https://darwininamerica.wordpress.com/2014/09/29/the-control...

More useful calories to devote to awake activities such as communication, thought, planning and etc.

mentioned in the article:

>We should think of early human camps and bands as like a snail’s shell,” he says. Groups of humans may have shared simple shelters. A fire might have kept people warm and bugs away. Some group members could sleep while others kept watch.

> The awake ape: Why people sleep less than their primate relatives

1. Because I gotta get up and go to work. And I can't sleep at work T_T

2. Because I waste time on HN.

> And I can't sleep at work T_T

Sounds like it is time for you to find a new job. :)

my keys to a good (8 hour+) sleep

- exercise daily

- no food / screens 2 hours before bed

- blackout curtains

- discontinue usage of an alarm -- wake up naturally

I have done all of these for a long time but still find myself waking up earlier as I get older despite no changes to going to bed.

A friend let me in on the real secret: "I've never slept better in my life than I have since retiring. I get up when I want, and I feel no need to maximize my evenings with late nights because i have my actual days."

In addition to the aforementioned items, I've recently accidentally discovered that I sleep way better with earplugs. Silicon ones (they require some know-how when it comes to putting them in properly, which is mostly a process of trial and error) work best for me, because of their comfort and decent sound insulation. I'm apparently sensitive to all the small noises around me (refrigerator, random street sounds, etc).

Another thing that helped me is reducing my water intake (this might vary a lot per person). I suspect I had a form of electrolyte imbalance, because I've been drinking a lot of water, but still felt thirsty quite often. I've learned that balance is key when it comes to hydration, so now I drink a bit less of fluids but as a result feel overall a lot better. I also try to include more of magnesium and potassium rich foods in my diet.

Instead of using the alarm to wake up, try setting it as a reminder to go to bed.

- don't have children

Media (backed by ‘science’) keeps telling me that sleeping longer than 8 hours a night ups chances of having heart disease etc. Guess people think it’s unhealthy?

I'm not seeing that claim in the media.

There is a statistical association between having among the longest sleep times and having health issues of that sort, but I don't know that the causality has been sorted out. If there is a direct cause and effect relationship my favored hypothesis would be in the direction that severe health issues promotes an increased need for rest and recovery.

Like this [0]. I saw quite a lot of it.

[0] https://www.bhf.org.uk/informationsupport/heart-matters-maga...

Naw, that's just fiction for the overworked to make them feel better about their heinous lifestyle.

Tldr: it's coffee. ;)

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