Quote from zarlan

Quote from LazyReviewer

Night owl, but it might be killing me, and I'm trying to change it.

No, it's forcing yourself to keep a different sleep rhythm, than your biological clock dictates, that is harmful. Not sleeping/waking late, because that's what your body wants.

Waking up at a normal time is starting to feel better than staying up late normally does for me.

If you're naturally waking up and feeling sleepy, earlier than you used to, if you are naturally starting to tend that way, then that'd indicate that your rhythm is changing.

Hear me out: It's called a summary. I don't put every detail into it. You've basically said, "No," while making a bunch of assumptions. I've not said anything incorrect, I just haven't gone into detail about why that summary is true. You've touched on some (but not all) of that why, not disproven my statement. Also, do you have a source that proves people can't change their own natural sleep rhythm? I'm interested to read it for the sake of learning.

Anyway, for a list of possible ways my summary is true:

• The question asked was "What is your sleep cycle?" and not "What is your natural sleep cycle?"

• Bad sleep, over long periods of time, tends to shorten one's lifespan. It also, in the more immediate, weakens the immune system.

• There's this literary device called "hyperbole," in which something is dramatized to the extreme for the sake of telling something in a more interesting way or increasing impact of a statement. Bad sleep feels awful... perhaps it makes one say it's killing them. Like their job could be killing them. Or someone else's behavior that affects them but isn't actually lethal.

• Learned behavior (habits) can cause one to ignore a changing sleep rhythm. One might want to change those habits if they've begun to cause issues with a person's natural sleep rhythm.

• Other health issues—genetic, psychological and physiological—can complicate this topic and make it so that some people can willingly change their natural sleep rhythm and some can't.

By the way, humans' most natural sleep rhythm is as follows:

1. Go to bed when the daylight is gone.
2. Sleep 3-4 hours, then wake up for 1-2 hours.
3. Go back to sleep for that last 3-4 hours. It's worked that way for thousands of years before the industrial revolution.

8 continuous hours was a workers union response to factories not letting their employees get enough sleep.

I'm a jack of all trades but master of none. Too many jars and not enough hands.

I am forced by work to be an Early Bird, but when I don't have to follow a schedule, I gradually move back to Night Owl.

Quote from LazyReviewer

Hear me out: It's called a summary. I don't put every detail into it.

You said you're trying to change when you sleep/wake, from when your circadian rhythm wants it to be. Regardless of details, that is deeply harmful.

Also, do you have a source that proves people can't change their own natural sleep rhythm?

You're the one who would need to show evidence, of that being possible. There is no evidence, of anyone ever doing anything of the sort. Indeed, there is not so much as a single claim of that being possible, anywhere.
If it was, it would be mentioned somewhere. It isn't.

• The question asked was "What is your sleep cycle?" and not "What is your natural sleep cycle?"

The terms "early bird" and "night owl", are only ever used to refer to peoples natural tendencies.
Not to when they actually wake/sleep.

...and most night owls, actually wake up early. (due to being forced to, because of society. More directly, because of work/school)

• Bad sleep, over long periods of time, tends to shorten one's lifespan. It also, in the more immediate, weakens the immune system.

My point exactly!
...and forcing yourself to sleep/wake at times that are in conflict with your biological clock, is bad sleep.

• There's this literary device called "hyperbole,"

I didn't say anything about the "killing me"-bit, so that comment is pointless and irrelevant.

• Learned behavior (habits)/.../

...cannot change your circadian rhythm.
You cannot show me any evidence, of that being even remotely possible. (also, whilst all habits are learned behaviours, far from all learned behaviours are habits)

• Other health issues—genetic, psychological and physiological—can complicate this topic and make it so that some people can willingly change their natural sleep rhythm and some can't.

None of that complicates, or has any relevance to, the issue we're talking about. (we, as in we two. It's not entirely irrelevant, to the general topic of this thread, IMO)

By the way, humans' most natural sleep rhythm is as follows:

That myth has been thoroughly debunked.

That comes from a study that assumes that people in northern/northern-ish Renaissance Europe, during winter, are somehow representative how what humans are naturally adapted/evolved to behave ...which is preposterous.
Studies that look at how stone age people would live (such as looking at primitive peoples, living much as if they were in the Stone Age), show that people tend to sleep in one single chunk, rather than biphasic sleep.

Also, that chunk shouldn't necessarily be eight hours long. Some need more, some need less. (some lucky bastards, needing no more than four! With no negative health impacts!)

Quote from xgemina

I am forced by work to be an Early Bird, but when I don't have to follow a schedule, I gradually move back to Night Owl.

Saying you are forced to be an early bird, is saying that you're forced to naturally wake up early, be most active early in the day (and gradually being less active), and naturally getting sleepy, early.

As opposed to having to set an alarm to wake up far earlier than you want to, wake up weak and miserable (due to waking up too early), being more active later in the day, and naturally wanting to stay up late, even though you have to sleep earlier than that, to get enough sleep (indeed, being quite capable and willing of doing very active work, right when you have to sleep)
...which is the typical experience of a night owl. (as opposed to the rare experience of a night owl, who doesn't have some job or school, that doesn't forces them to wake/sleep early. That can, instead, wake/sleep at times that are natural for them)

Quote from zarlan

Even if you sleep the right amount, and do everything to ensure good quality sleep, if your forcing yourself to wake up way earlier, or sleep way later, than your body needs, then you're going to get bad sleep. And sleep is way more important than people realise!

Well i think you missed the part where person said they wake up before 7:30 AM even without an alarm, so they decided to go sleep earlier so that it matches their own biological rhythm...

I am envoy from nowhere in nowhere. Nobody and nothing have sent me. And though it is impossible I exist. © Trimutius

Quote from zarlan

Quote from mallika23

Originally, I'm not an early bird. But since I got my new job, I have to become one. 😂

No. Waking up early, doesn't make you an early bird. Naturally waking up early, makes you an early bird.

It started because my job requires me to wake up early (at least at 5), but now it becomes a habit. Eventually, my body/sleeping cycle adjusts to this habit. I could automatically wake up at 5 even without an alarm.

Quote from zarlan

Quote from mallika23

Originally, I'm not an early bird. But since I got my new job, I have to become one. 😂

No. Waking up early, doesn't make you an early bird. Naturally waking up early, makes you an early bird.

It started because my job requires me to wake up early (at least at 5), but now it becomes a habit. Eventually, my body/sleeping cycle adjusts to this habit. I could automatically wake up at 5 even without an alarm.

Edit: And if I may add (since I've just read the whole debate about the sleeping cycle here), human can indeed change their sleeping cycle. Based on my experience, it just started from the habit.

On my previous job, the job started at 9am, and it's only 15 mins away from my house. I can wake up at 8 and still would not be late.

After that, I went freelance for a few years, and my sleeping cycle change. I can wake up at 9 or even 10, and started to work until late.

And now, on my current job, I have to wake up at 5 or at least 6 since the working hour started at 7.

Whether these sleeping cycles bad or not, it's a different topic, of course, though I'm still healthy so far.

Quote from Trimutius

Well i think you missed the part where person said they wake up before 7:30 AM even without an alarm, so they decided to go sleep earlier so that it matches their own biological rhythm...

How so? Where did I say anything about their cycle and efforts in regards to it, other than encouraging them, to do exactly that?

Quote from mallika23

It started because my job requires me to wake up early (at least at 5), but now it becomes a habit. Eventually, my body/sleeping cycle adjusts to this habit. I could automatically wake up at 5 even without an alarm.

Having trained yourself to wake up earlier, isn't the same as changing your inherent biological cycle.

Whether these sleeping cycles bad or not, it's a different topic, of course, though I'm still healthy so far.

People who force themselves to wake up, with an alarm clock and/or don't get enough sleep and/or have bad sleep quality, will typically say that they are healthy, so...

Quote from zarlan

Quote from flowinmyboat

Getting a consistent amount of sleep each night is more important than when you sleep, I think

Nope. The science is very clear, that when you sleep is very important. As in, whether or not it fits your biological clock. (i.e. you really should wake up at 7:30, as your body clearly wants)

There are several aspects to proper sleep:
The amount is important (there is significant variation, in how much you need), but also the quality
...and the timing!
Even if you sleep the right amount, and do everything to ensure good quality sleep, if your forcing yourself to wake up way earlier, or sleep way later, than your body needs, then you're going to get bad sleep. And sleep is way more important than people realise!

It would add to your point in you cited the science. You are referring to the circadian cycle or rhythm, which is referred to as a biological clock, however the science around it is not “clear” - otherwise, we’d have effective treatments for people with sleep disorders. Sleep medicine, like nutrition science, is a field that is notoriously hard to measure things in because there are so many variables and biological processes at play. However, circadian cycles are not immutable internal clock. It’s a complex, tightly regulated but still poorly understood process. There are a lot of studies of swing shift workers (that is, people who have to work days and then nights sometimes and thus change their sleep-wake cycle regularly) and their health in relation to this.

Here is a brief primer from StatPearl with references: https://www.ncbi.nlm.nih.gov/books/NBK519507/

EDIT: However, that said, I agree on your points that society does force everyone onto the same schedule, and then goes beyond by having 24-hr services and creating swing shifts, causing further disruptions. Even if we’re all on the same schedule, we are not all subject to 1) the same external stimuli, and 2) do not have the same response to hormonal changes or changes in light-dark or ability to get deep sleep (REM sleep). Society is a bit crueler to people who have a baby that wakes them up in the middle of the night and expects them to be alert and ready at 7AM again. Or to the student who’s expected to go to school all day, do homework all evening, and cut their fun short to sleep before getting up again at 6AM in time for a 7AM bell, despite evidence to suggest adolescents need more sleep (likely because their hormones are different than the adults who set the schedule). Or to the person who just has the pattern of sleeping at 4AM and waking at 12PM, because we as a society have deemed people who get up in the afternoon as “lazy.”

http://i.imgur.com/LxhWm.jpg (will reformat this some day…)

Quote from flowinmyboat

It would add to your point in you cited the science.

I assume you meant "if" Setting aside how internet forums/chats tend to shun/punish citing (though I am absolutely in favour), making it weird to criticize someone for not having cited (asking for citations is to be encouraged, IMO, but criticism for not having done a thing, that you'd usually get shit for...):

1. I can't be expected to remember everything.
2. I have no need to cite specific sources, when talking about the scientific consensus. Look it up, in any reliable source. What sources have I read, that said these things? Everything I've read on the topic.

You are referring to the circadian cycle or rhythm, which is referred to as a biological clock, however the science around it is not “clear” - otherwise, we’d have effective treatments for people with sleep disorders.

That is a preposterous statement!
The science being clear on the specific points I said that the science was clear on, merely means that it is clear on those points.
Not that all of sleep science is 100% fully understood (or even that those points are fully understood), with countermeasures developed and everything. Just that what is currently know about those specific points, is clear.

Oh, and...

otherwise, we’d have effective treatments for people with sleep disorders.

If you were correct, in your notion that the circadian rhythm has been demonstrated to be mutable, THAT would mean that we'd have effective treatments for people with sleep disorders! (note, however, that being a night owl, is NOT a disorder. Society forcing night owls to wake/sleep early, is the disorder!)

However, circadian cycles are not immutable internal clock. It’s a complex, tightly regulated but still poorly understood process.

Aside from your baseless claim, that it isn't immutable, what you say there is fully correct ...and none of it goes against what I've said. (aside from, again, the notion that it isn't immutable)

If you just said that it is possible, that it might be mutable, that would be perfectly valid ...and also completely pointless and irrelevant, as there is not only no evidence of such a possibility but also, far more importantly, there is no known way to actually modify it.

There are a lot of studies of swing shift workers

...and you cite none, that comes anywhere close to supporting your case.
No mention, whatsoever, about being able to change the rhythm.

Here is a brief primer from StatPearl with references:

...which does nothing to support your case, or say anything that disagrees with anything I've said. Nor does it state anything I was unaware of. (aside from the cellular details and the like, which I don't bother with. They're not relevant to any of this, anyway)

EDIT: However, that said, I agree on your points that society does force everyone onto the same schedule, and then goes beyond by having 24-hr services and creating swing shifts, causing further disruptions.

... You can't, on one hand, (rightly) criticize society for forcing everyone on the same schedule, and then also criticize having 24-hr services, which both allows people to use the services regardless of their circadian rhythm, and for people with other rhythms to have jobs that fit it! It's one or the other!

Swing shifts, however, are 100% unjustifiable, indefensible, immoral, unethical, harmful, and need to be strictly illegal!

Or to the student/.../

No, the issue isn't that they need more sleep.
They do, but...
It's that adolescents tend to have a later circadian rhythm. People tend towards having a rhythm of waking/sleeping late, at that age (with individual differences, obviously, but generally speaking, on average...), which means that forcing them all to get up at 6-7, is child abuse. The only evidence of mutable circadian rhythm, is the clearly undeniable fact, are the changes to it, that happen with age. (very tiny kids wake relatively early, adolescence late, senior citizens early)

Oh, and also, studies on homework, show that it's mostly bad. School work should be done at school, with very minimal homework. (with only some kinds of homework, and not much of it, being justifiable)

because we as a society have deemed people who get up in the afternoon as “lazy.”

Anyone who wakes as late as noon, or even 9-10, is deemed lazy.

Quote from zarlan

Quote from Trimutius

Well i think you missed the part where person said they wake up before 7:30 AM even without an alarm, so they decided to go sleep earlier so that it matches their own biological rhythm...

How so? Where did I say anything about their cycle and efforts in regards to it, other than encouraging them, to do exactly that?

It appeared to me that you were talking how it won't work for everyone... But OP never even claimed that it should work for everyone... Sorry if i got a wrong impression...

I am envoy from nowhere in nowhere. Nobody and nothing have sent me. And though it is impossible I exist. © Trimutius

Quote from Trimutius

It appeared to me that you were talking how it won't work for everyone... But OP never even claimed that it should work for everyone... Sorry if i got a wrong impression...

What you quoted, didn't adress her rhythm, other than to (in a parenthesis) say that she was right to stop fighting her circadian rhythm. (i.e. the exact opposite of your impression) It was mainly addressing the general claim, that getting a consistent amount of sleep was more important than the timing of sleep, which I pointed out as false. Both are very important; even if you get a consistent, and sufficient, amount of sleep, your sleep will be bad, if it clashes with your circadian rhythm.

I fail to see how either of those two facts, was anything other than crystal clear and obvious.

Quote from zarlan

Quote from LazyReviewer

Hear me out: It's called a summary. I don't put every detail into it.

You said you're trying to change when you sleep/wake, from when your circadian rhythm wants it to be.

I said, "Night owl, but it might be killing me, and I'm trying to change it."

Where on Earth is "circadian rhythm" mentioned? Those are your words and assumptions, not mine. My habits, from when my natural sleep cycle was in the morning to afternoon (something I arguably developed when I had a television in my room as a teenager and stayed up late watching a screen - and I'll mention more about screens down below), have kept me in that night owl section of living despite the fact going to sleep at night now gives me better rest. I'm trying to change it so that my habits now match my natural sleep cycle.

However, why I'm getting more rest by waking up in the morning now, could potentially be caused by some recent mental and medical issues I've been having. I'll give more detail down below.

Also, do you have a source that proves people can't change their own natural sleep rhythm?

You're the one who would need to show evidence, of that being possible. There is no evidence, of anyone ever doing anything of the sort. Indeed, there is not so much as a single claim of that being possible, anywhere.

You made the claim, I want the study.

If it was, it would be mentioned somewhere. It isn't.

Allow me to point out to several anecdotes about people my parents knew who had to work night shift for years, and when they retired and tried to return to their original natural sleep rhythm from decades earlier, they died within months.

Do we have studies 3 decades long that prove or disprove their work forced their natural rhythm to change? Because things like neuroplasticity, where reinforcing thoughts and patterns physically changes the brain, is a proven fact. I would argue that, through neuroplasticity, one's natural sleep rhythm could be altered.

As for why mine has recently changed, as previously mentioned, I've been going through some things recently, including potential long covid (and MRIs have shown covid can change the brain - press(dot)rsna(dot)org/timssnet/media/pressreleases/14_pr_target.cfm?id=2381).

• The question asked was "What is your sleep cycle?" and not "What is your natural sleep cycle?"

The terms "early bird" and "night owl", are only ever used to refer to peoples natural tendencies.
Not to when they actually wake/sleep.

By my understanding, the terms apply to when someone is generally awake, regardless of why.

Furthermore, I've known several people who adjust to new sleep schedules after about 2 weeks. How do I know? Because they complained to me about their rotating shifts, specifically that they just got used to the new sleep pattern when the shift rotated at 2 weeks, and how it was better at other work places that rotated every month.

• There's this literary device called "hyperbole,"

I didn't say anything about the "killing me"-bit, so that comment is pointless and irrelevant.

You replied to my comment about it killing me by saying, "No...(explanation)...that's harmful." It's quite implied, and I don't know how else that could have been interpreted with the way you worded it. But I digress, this isn't relevant to the broader discussion at this point.

• Learned behavior (habits)/.../

...cannot change your circadian rhythm.
You cannot show me any evidence, of that being even remotely possible. (also, whilst all habits are learned behaviours, far from all learned behaviours are habits)

Here: https://sleepopolis.com/education/reset-circadian-rhythm/ https://www.webmd.com/sleep-disorders/find-circadian-rhythm

These articles state circadian rhythm can be changed gradually over time. And since light heavily affects one's circadian rhythm, reading manga on a phone, playing video games, and other activities with screens before going to bed, are habits that affect circadian rhythm.

• Other health issues—genetic, psychological and physiological—can complicate this topic and make it so that some people can willingly change their natural sleep rhythm and some can't.

None of that complicates, or has any relevance to, the issue we're talking about. (we, as in we two. It's not entirely irrelevant, to the general topic of this thread, IMO)

All of that complicates and has relevance to our discussion.

By the way, humans' most natural sleep rhythm is as follows:

That myth has been thoroughly debunked.

That comes from a study that assumes that people in northern/northern-ish Renaissance Europe, during winter, are somehow representative how what humans are naturally adapted/evolved to behave ...which is preposterous.
Studies that look at how stone age people would live (such as looking at primitive peoples, living much as if they were in the Stone Age), show that people tend to sleep in one single chunk, rather than biphasic sleep.

Can you please show me the study that supports this claim? The only caveman sleep study I found was this: pmc.ncbi.nlm.nih.gov/articles/PMC4067433/ and it admitted they couldn't tell things like naps taken and biphasic sleep (something that does happen in the few remaining hunter-gatherer societies today).

Also, there was a pushback by an author who did European studies who pointed out that biphasic sleep was all over the world, even in equatorial regions. pmc.ncbi.nlm.nih.gov/articles/PMC4763365/

That isn't to say they were defending it happening in the stone age, but the fact there's evidence biphasic sleep was everywhere before the industrial revolution, would suggest that it might not just be a myth that cavemen had biphasic sleep.

Also, that chunk shouldn't necessarily be eight hours long. Some need more, some need less. (some lucky bastards, needing no more than four! With no negative health impacts!)

I agree, 8 hours is not for everyone. I'm just saying that the current layperson understanding of 8 hours of steady sleep being required ultimately comes from a workers union back in the early industrial revolution. I'm not saying they were scientifically correct about everyone. They were pushing back against abusive factory owners and they came to the conclusion that 8 hours was needed. What I find most interesting is that we see the societal effects of that even today with 8 hour shifts being so common (which I think is neat, considering how long ago that was).

I'm a jack of all trades but master of none. Too many jars and not enough hands.

Quote from LazyReviewer

I said, "Night owl, but it might be killing me, and I'm trying to change it."

Where on Earth is "circadian rhythm" mentioned? Those are your words and assumptions, not mine.

...
First of all, this topic is 100% about ones circadian rhythm.
Secondly, you talk about circadian rhythms, later in the comment, so...
Saying you don't know what it is, here, is a clear lie.

Also, you're trying to lecture me on the subject, when you state that you don't even know something so basic and fundamental to it? That you haven't even spent a few minutes, looking it up (anyone who does, will instantly encounter the term, and its definition, after all)

As for when you mention circadian rhythms...
Your initial comment is all about it, and the second one is full of mentions.

My habits, from when my natural sleep cycle was in the morning to afternoon

So you'd wake up in the morning, and sleep in the afternoon? 🤨
Learn how to be intelligible.

despite the fact going to sleep at night now gives me better rest.

Ah, so you were talking about when you'd go to sleep! You used to sleep in the morning, or afternoon!
...
Yeah, I have no fucking clue, what the hell you're saying was your habits. What you've written, is as clear as mud.

I'm trying to change it so that my habits now match my natural sleep cycle.

That is the exact opposite of what you said in your initial comment!

You made the claim, I want the study.

No, YOU made the claim, in your second comment, when you said "Also, do you have a source that proves people can't change their own natural sleep rhythm?"
I hadn't addressed the issue, at all
...and I have pointed out, that if it was possible, it would routinely used. It would certainly be known to doctors! (and trust me: it isn't!)

Also, why would there be a study to prove it can't be changed? That is the default position. It is the ability to change it, that needs to be demonstrated.

Allow me to point out to several anecdotes/.../

...
Anecdotes!?
Seriously?
🤦

when they retired and tried to return to their original natural sleep rhythm from decades earlier, they died within months.

As if!
Even if that story isn't made up, there is nothing to indicate that the effort to return to their natural rhythm had anything to do with it.

Because things like neuroplasticity, where reinforcing thoughts and patterns physically changes the brain, is a proven fact.

...and it's a proven fact, that there are plenty of things, that no amount of neuroplasticity is going to change, so...

I would argue that, through neuroplasticity, one's natural sleep rhythm could be altered.

...with zero evidence.

As for why mine has recently changed, as previously mentioned, I've been going through some things recently, including potential long covid

Sure, I can believe that an illness, or maybe even some rare type of injury, might be able to affect your circadian rhythm ...or it could be that you're getting old. (as I've mentioned, you tend to wake/sleep earlier, when you get old)

By my understanding, the terms apply to when someone is generally awake, regardless of why.

Then your understanding is wrong.
That is not how the terms are used.
At all.
Also not how it is typically defined in dictionaries, much less encyclopedias.

Furthermore, I've known several people who adjust to new sleep schedules after about 2 weeks.

The fact that people can adjust to sleep schedules that clash with their natural sleep cycle, is 100% irrelevant.

You replied to my comment about it killing me by saying, "No...(explanation)...that's harmful." It's quite implied, and I don't know how else that could have been interpreted with the way you worded it.

There is no reasonable, rational, or sane way, to interpret it, in whatever way you did. (and I have no idea, how you interpreted it, to connect the "no" or "that's harmful", to the "killing me"-bit)

I was obviously referring to your saying "I'm trying to change it."

Here: https://sleepopolis.com/education/reset-circadian-rhythm/

You linked to an article on a bed store!?
Seriously?

https://www.webmd.com/sleep-disorders/find-circadian-rhythm

Not a scientific study, not peer-review...
It mentions chronotherapy, though not by name (intentionally sleeping/waking X minutes/hours earlier/later each day, to gradually shift your sleep schedule ...or skipping a night, and then going to sleep at the desired time), but that shifts your sleep schedule. Not your circadian rhythm.
That article seems to do nothing other than be sloppy with the use of the term "circadian rhythm".

And since light heavily affects one's circadian rhythm, reading manga on a phone, playing video games, and other activities with screens before going to bed, are habits that affect circadian rhythm.

No. They affect your sleep schedule. Not your natural/intrinsic rhythm.

All of that complicates and has relevance to our discussion.

No.

Can you please show me the study that supports this claim?

Studies.
And no, I don't have them memorised
...but that's not a problem, as becomes clear, below.

naps taken and biphasic sleep (something that does happen in the few remaining hunter-gatherer societies today).

What basis do you have, for that claim?

Also, there was a pushback by an author who did European studies who pointed out that biphasic sleep was all over the world, even in equatorial regions. pmc.ncbi.nlm.nih.gov/articles/PMC4763365/

...
Why do you ask me for a study, when you are already aware of it, through a study that pushes back on it? (and, obviously, cites it)
How were you unable to find that?
...and no, don't try to claim, that the study that it's a pushback on, is the minor one you mentioned before it! It clearly isn't!

The study clearly looks into naps and biphasic sleep
...and napping during the day is NOT the same as waking for a period during the night, to then have a second sleep. One nap during the day (assuming it's just one), and one period of sleep during the day, can also be called biphasic sleep, but...
it's a different kind of biphasic sleep.

As for the pushback study...
It mentions the Tupinamba Indians (an agrarian society) and the people in Muscat, Oman, in the late 1800s. (far from hunter-gatherers!)
...and then a bunch of others, that are similarly far from being hunter-gatherers.
You do get ONE mention of a group that is:
Where the paper quotes an anthropologist saying:
“A G/wi camp never has an uninterrupted night's sleep. There is always someone awake, adding wood to the household fire, eating a snack, seeing to a child, listening to a strange noise in the bush, or keeping watch if dangerous animals are near. For this reason, the divisions of the night are almost as important as those of the day."
...
The paper only says that, that quote is "at the least suggestive", but...
There always being someone in the village, who is awake, doesn't have anything to do with the notion of people waking up in the middle of their sleep, to have a bit of a waking period, and then a "second sleep".
It means that they sleep in shifts. (they would have to, regardless of whether they had monophasic or biphasic sleep)
Ideally due to them just simply having various people, with various natural cycles, such that there is always someone who is naturally awake.

In other words, nothing in the paper, is actually relevant.

The studies on actual hunter-gatherers, all show that they have monophasic sleep.

I'm just saying that the current layperson understanding of 8 hours of steady sleep being required ultimately comes from a workers union back in the early industrial revolution.

No it doesn't.
It comes from the fact that science says, that the average person (or median? Most people, at any rate) needs about eight hours of sleep.

They were pushing back against abusive factory owners and they came to the conclusion that 8 hours was needed.

Their negotiations with the factory owners, was about the length of time they worked. Not how long they slept.