[stared]

> Familial Natural Short Sleep (FNSS), a benign mutation that allows them to sleep 1-2 hours less than the recommended 7-9 hours, without experiencing the negative effects of sleep deprivation.

Sleep deprivation is one concern, but there’s a more subtle impact on cognitive functions (working memory, creativity, deep focus), overall health (particularly the endocrine and immune systems), and long-term health outcomes (such as an increased risk of dementia).

When I was younger, I was fascinated by various optimized sleep schedules. However, I noticed a stark contrast: many of my math friends consistently slept 9–10 hours a day. They needed that—not just to function in daily life but to achieve the deep focus required for their work. Living on less sleep might not affect immediate action (and in some cases, it might even seem to enhance focus on doing), but it can impair deeper, more complex thinking.

Some suggest that one of sleep's key roles is to help the brain regenerate. Chronic sleep deprivation, in turn, is linked to a higher risk of dementia. For anecdotal evidence: Churchill and Thatcher, known for boasting about sleeping only 4–5 hours a night, experienced significant cognitive decline later in life.

[Aurornis]

> When I was younger, I was fascinated by various optimized sleep schedules.

I was also fascinated with alternate sleep schedules when I was younger. Some of the books and biohackers of the time made them sound like magical ways to get more hours out of the day.

Then every single experience report I found that was not coming from someone trying to sell me a book or get me to subscribe to their newsletter, YouTube, or other social media was extremely negative. Nobody who tried these had continued them very long. After going back to regular sleep schedules they felt significantly better. A common report was that they didn’t realize how badly sleep deprived they were until they stopped the alternate sleep schedule and went back to normal sleep.

A lot of the sleep biohacking reports follow a similar trend: People who try alternate methods of minimizing sleep don’t realize the negative effects until they quit. This is also true for people who rely on stimulants (caffeine or stronger) which mask feelings of sleep deprivation but can’t actually reverse the negative effects of sleep deprivation.

[safety1st]

Okay, but none of that is relevant to the article. This article is about a genetic condition called FNSS which results in you getting a full night's sleep in less time. It specifically addresses the concern that there might be unobserved negative effects and that so far, we haven't found any. If you have FNSS there is no reason to try and force yourself to sleep for 8 hours a night and it is not something being sold on YouTube.

[theptip]

You’re missing the point being made in this thread, which is that there might be subtle long-term impairments to the genetic condition described in the OP.

Indeed the article discusses this thoroughly, noting that since it’s a very small sample you can’t rule out anything but very strongly negative fitness impact.

There’s simply not enough data to rule out the hypothesis that folks with this condition are slightly sleep-deprived vs their theoretical without-mutation genotype baseline.

[lll-o-lll]

> > Familial Natural Short Sleep (FNSS), a benign mutation that allows them to sleep 1-2 hours less than the recommended 7-9 hours, without experiencing the negative effects of sleep deprivation

> Living on less sleep might not affect immediate action (and in some cases, it might even seem to enhance focus on doing), but it can impair deeper, more complex thinking.

You are making a mistake in thinking the aforementioned genetic variation “enables people to get by on less”. They just literally sleep less. I have a brother in law with this, and it’s a bit annoying for him as his wife needs the normal 8 hours a night. He cannot sleep 7-8 hours, only 6. He just reads in the bed for 2 hours a night. If he has too much to do, he skimps like we all do, but for him this is 4 hours a night during the week (needing to catch up on the weekend).

Other than sleeping less than others, he’s regular in every way. Very successful engineer, if it helps, certainly requires “deep thought” on the regular.

It is unfair, but so many genetic advantages are equally unfair.

[djtango]

This is true, I was neighbours with one of the top mathematicians in my uni and he slept what felt like an excessive amount everyday.

I definitely underperformed academically due to sleep deprivation and I probably benefited greatly during my revision period because I had a very strong sleep routine.

That said, I entered my final exam having only slept probably less than two hours and that was 100% the right call because the extra cramming was necessary and drove the needle significantly.

[vacuity]

Sleep deprivation affects many different things, some of which are salvageable with stimulants like caffeine, and certain functions are fairly unaffected. Exams that can be solved mostly with rote memorization are less impacted by sleep deprivation than exams that require spontaneous creativity. In any case, glad to know it went well for you!

[blueblimp]

> many of my math friends consistently slept 9–10 hours a day.

Anecdotally, I've noticed an association between long sleeping and math ability in particular, so this doesn't surprise me. I wonder if it's been studied scientifically.

[euroderf]

> I noticed a stark contrast: many of my math friends consistently slept 9–10 hours a day.

I'm curious, in order to reach this duration, did they need to do some kind of exercise at some point in the day, to gain physical fatigue ? Or could they sleep this long whilst being (I exaggerate here) couch potatoes ?

[cvoss]

You say that like it's hard for an oversleeper to achieve their oversleeping. As an oversleepr, I'll suggest that it's the other way around. When you're an oversleeper, the thing that's hard is to stop sleeping after the socially normal amount of time.

[mettamage]

Being able to just sleep 10 hours every day seems like an unfair advantage.

[maleldil]

Why would it be an advantage? Aren't you "losing time"?

I need 10 hours every day, so even if I go to bed at 10pm, I'd wake up at 8am, which is "late" for most people.

I'd love to be able to wake up at 6am, but just can't. It doesn't feel like an advantage.

[cortesoft]

> I'd love to be able to wake up at 6am, but just can't.

What does "just can't" mean, exactly? Just curious, because I felt that way, too, until I had a newborn and was forced to wake up with less sleep and discovered it was physically possible. Still felt awful all day, but it was possible.

[withinboredom]

For me, alarms simply don’t wake me up. I’m literally unconscious and not just asleep. That being said, I only need 6 hours of sleep a night and I can’t sleep any more than that. However, I also have delayed sleep entry. So, I usually stay up until 1am and wake up at 7am, with no alarm. If I want to sleep less than six hours, I simply won’t wake up. Famously, in the military, I was dragged outside, to the morning formation, and slept through the entire thing. It was entertaining enough that I didn’t get in too much trouble, but alarms simply don’t work for me. I ended up getting doctors orders to always get six hours of sleep, if possible, instead of the 4 hour minimum. I was always worried I would sleep through important things in a war zone; and I did. I just never got caught or admitted to it.

[necovek]

Do you have DST where you live? Do you suddenly adjust to the new time when travelling to a different timezone?

(All this to say that you sleeping 6h flat is plausible, but times-of-day are a human, social construct, and it's impossible for your body not to be able to adapt to going to bed earlier and waking earlier)

[maleldil]

I meant that I can't sleep 8 hours and feel rested. If I'm forced to sleep less than I need, I'd be sleepy and tired all day. Taking a nap helps but isn't always possible, and is even less time efficient.

[mettamage]

I would physically not be able to do this. I think many people would have a hard time to sleep more.

Moreover, when I sleep more, I notice that I'm sharper and I find it easier to take on tough challenges: this means that sleeping longer makes me happier for the rest of the day. So I'm also willing to live a tougher life. So there's also a trade off with: yea, you have less time, but the less time that you have, you're happier. Or at least, that's my experience.

And not only are you happier, you're also more capable. So it's more easy to live according to your own rationality and it's easier to not live according to your emotions and instincts.

Again, just my experience.

[roland35]

I think they mean that having the time available for sleep at all is a bit of a luxury. A lot of people need to take care of their family, or work an extra job, etc and can't afford to sleep much extra.

[mgh2]

Related: https://news.ycombinator.com/item?id=41942096

[homebrewer]

Churchill also drank heavily and smoked like a chimney, don't you think that might have more to do with his cognitive decline than anything else?

[tonyedgecombe]

I remember reading that Thatcher used to nap regularly throughout the day. She probably got more sleep than was stated at the time.

[warrentr]

Same with Churchill. He would arrange for his afternoon nap and bath even when visiting other countries

[setsewerd]

Napping is also associated with dementia, I wonder if that's explained by sleep deprivation? Could be that you don't get as much (if any) deep sleep during shorter naps, compared to a full night's sleep.