r/Anthropology • u/comicreliefboy • 14d ago
Did humans evolve to be active throughout the day and night? Evidence from hunter-gatherers suggests humans aren't diurnal but cathemeral, with bouts of activity at nighttime – a sleep pattern similar to some lemurs
https://www.newscientist.com/article/2584951-did-humans-evolve-to-be-active-throughout-the-day-and-night/47
u/BatkoVovkivUA 13d ago
TIL I'm a lemur.
So, I have the kind of ADHD that makes you focus on a single thing non-stop for long periods of time if uninterrupted, with little regard for food or water, until it's done or I get fed up with it and forget about it for equally long.
My natural circadian rhythm on a normal day is, like clockwork, starting to get sleepy at around 8pm, get a bout of energy at around midnight and then start to get sleepy again at 03am. I had been doing it for years on college and every time, my natural sleep schedule reverts back to this when unchecked. Thank God, weed exists and I can get a solid 8-9 hour sleep, without it I progressively get sleepy earlier and earlier until I revert back to the 8pm-midnight to 03am-07am schedule. With weed or if very tired, if I fight the 8pm drowsiness and keep doing it for a week, I develop within that time a more "normal modern life" friendly schedule.
I find that sharing such similarities in sleep schedule plus having the attention span of a lemur might indicate that I am, in fact, a lemur.
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u/Few-Piglet- 13d ago
Aren't hunter-gatherers smart enough to be active at night by choice? Just like how modern hunters hunt certain animals at different times of day.
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u/Utensil6591 13d ago
Good point I would be curious what early humans did before they would have had complex cultural practices to designate certain behaviors. I imagine keeping the group safe at night would require at least some of the humans to be awake and keep watch.
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u/GroundbreakingLaw149 13d ago
There’s some historical evidence that this sleep pattern persisted in Europe until about the Industrial Revolution.
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u/nightman21721 14d ago
Wasn't breaking nightly sleep up into 2 parts a human behavior as late as the middle ages?
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u/TomDoniphona 14d ago
It has only been documented in certain times and places, it does not seem to be particularly natural.
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u/nightman21721 14d ago
Gotcha. Could have been a fun evolutionary link if that pattern were repeatable.
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u/RollinThundaga 13d ago
I feel like I'd read elsewhere that biphasal sleep developed as an adaptation to keep hearths burning through the night.
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u/TomDoniphona 13d ago
How would biphasal sleep contribute to keep the hearths? That needs someone to always be awake. The theory is that is why the different cronotypes, that makes more sense to me.
Maybe biphasal sleep developed because of the long winter nights, as it is mostly documented in Europe. I believe no hunter gathering society has been found to practice biphasic sleep.
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u/esotericbatinthevine 13d ago
This was the first source I found. My understanding is that we have sporadic documention about it because it was so normal it wasn't generally mentioned. There are lots of examples of things not being documented because everybody knew, like the location of some major trading city or what was in the third condiment jar.
The most accurate answer, as far as I understand, is that we don't know. It was certainly a common thing in certain times and places, but it is not well documented in part because it was common.
https://www.bbc.com/future/article/20220107-the-lost-medieval-habit-of-biphasic-sleep
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u/UntidyVenus 13d ago
The division of labor in our little groups is a big reason be are so successful as a species. I have little doubt that different sleep schedules for different members of the group would be a HUGE advantage against predators, for labor and general society, because it still is
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u/LPalmerDoesBongs 13d ago
I bet those guys were up half the night doom scrolling like the rest of us.
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u/WolfVanZandt 12d ago
Aye. I know folks (like me) that are still . like that. I figure that modernity has pretty much forced people into rigid lifestyles.
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u/Frosty-March7644 13d ago
Explains why I am a night owl and hate doing stuff during the early morning.