Need for Sleep

Work shouldn’t start until 10am and school even later, says sleep expert

Paul Kelley of Oxford University’s Sleep and Circadian Neuroscience Institute says society is in the midst of a sleep-deprivation crisis, as the working hours we force ourselves to adapt to are often unnatural and unsuitable for our internal body clocks. …

He advocates 8:30am starts for children aged eight to 10, 10am starts for 16-year-olds and 11am lessons for 18-year-olds.

“At the age of 10 you get up and go to school and it fits in with our 9-to–5 lifestyle,” Kelley said. “When you are about 55 you also settle into the same pattern. But in between it changes a huge amount and, depending on your age, you really need to be starting around 3 hours later, which is entirely natural.”

If Kelley’s right, what this effectively means is that our whole lives from the onset of our teen years through to the end of middle age are like being woken up too early. Every. Single. Day.

““Staff should start at 10am… Staff are usually sleep-deprived,” Kelly told the British Science Festival. “Everybody is suffering and they don’t have to. We cannot change out 24-hour rhythms.”

Can’t agree more. The 9-5 workday is a structural microaggression against people who identify as night owls like myself.

warning: crappy evopsych theorizing follows

In ancestral times, you didn’t want everyone dozing off at the exact same time. It would have made sense for someone to always keep an eye out for predators, enemy bands, etc. It would have been much easier to do so if society had a mix of night owls and early risers, just as they needed both altruists and psychopaths in certain proportions for optimal group survivability.

I just don’t feel all that great waking up very early in the morning, even if had a perfectly adequate night’s sleep beforehand. I wonder if sometime in the next decade science will show that the near universal advice to go to bed early and wake up early regardless of personal psychology will go the way the medical community old imprecations against salt, eggs, and butter.

There appear to be some people, typically very energetic ones, who don’t seem to need very much sleep at all. Elon Musk seems to be one of them, I suspect Razib Khan is as well.

As Peter Frost reported a few months back, African-Americans need on average one hour less sleep than European Americans. Assuming sleep is essentially just a way of keeping energy expenditures down when they’re not needed (humans can’t hunt or gather at night) it stands to reason that northern peoples would sleep more on average. Of course this is has not been germane since the industrial revolution and I for one would be happy to see the need for sleep (bio)engineered away altogether.

Anatoly Karlin is a transhumanist interested in psychometrics, life extension, UBI, crypto/network states, X risks, and ushering in the Biosingularity.


Inventor of Idiot’s Limbo, the Katechon Hypothesis, and Elite Human Capital.


Apart from writing booksreviewstravel writing, and sundry blogging, I Tweet at @powerfultakes and run a Substack newsletter.


  1. Yet employees don’t seem to care much about the timing of their work day. People seem oblivious of their sleep deprivation. I wonder why. (This might count as a good example of labor-market failure.)

  2. People aren’t oblivious. Just that most of us have no choice in the matter.

  3. Drapetomaniac says

    I sleep about 9-10 hours each night on a fairly regular (midnight to 10am) schedule. It seems quite beneficial for mood, focus, and energy.

    Extended sleep improves the athletic performance of collegiate basketball players
    Stanford study is the first to document how sleep extension affects the performance of actively competing athletes

    Although I wasn’t an extended sleeper when younger, it’s quite probable that longer sleep is more natural for me.

    The ABCC9 of sleep
    A genetic factor that regulates how long we sleep

  4. Razib’s exercise habit is a big help in shaving off needed sleep time. I need a good 8 hours of sleep or I’m a zombie. But when I’m seriously exercising and eating healthy this drops down to 6 hours.

    Howard Hughes could work for days without sleeping or eating. Tony Robbins and Martha Stewart sleep 4 hours per night. Trump needs 4 to 5 hours per night and is as sharp for a 6 am TV interview as he is at 11 pm, after a grueling 2-hour debate. President Ulysses S. Grant (great writer) said, “I can do nothing without 9 hours’ sleep.” Writer and humorist Steve Allen needed a minimum of 10 hours per night. Descartes needed 10 to 12 hours per night and would get up at noon. Artists and writers are night owls, e.g., Fitzgerald, Proust, Picasso. I think Steve Sailer said he needs 9 hours and appears to be a serious night owl.

    I have worked jobs that required me to be there at 7 am. I always felt sick getting up so early. And it left me depressed. And the feeling never changed if I got a good night’s sleep. It always felt unnatural and depressing. If Hell were a time it’d be between 4 am to sunrise.

    Another related and interesting subject you touched upon is diets. Some very prolific people have had seriously bizarre diets. Nikola Tesla lived on crackers and milk. Steve Sailor recently wrote about the Duke of Wellington’s diet of only rice. Physicist Oliver Heaviside would live on nothing but milk. Thomas Edison would go years consuming nothing but milk and occasionally orange juice.*

    *For a lot more fascinating information on this subject (sleep, diets, exercise, habits of doers) I recommend: Strange Brains and Genius: The Secret Lives of Eccentric Scientists and Madmen by Clifford Pickover (Plenum, 1998).

  5. dried peanuts says

    Napoleon is supposed to have needed a lot of sleep and deprivation of it on the night before waterloo is meant to have affected his performance. Mrs. Thatcher slept very little while in office and eventually went bonkers. I suspect sleep deprivation plays a role in politicians’ tendency to go bananas over time, see also, Blair, T., Brown, G.

  6. Cattle Guard says

    Thanks for being one of the few writers willing to stick up for us psychopaths!

    And on a slightly more serious note, I wonder if the sleep schedules of professional athletes (who have serious recovery needs) change when they retire. In theory they might suddenly need a couple hours less, but I’ve never heard anything that would indicate this actually happens. If anything, they complain that it’s hard to get out of bed in the morning because of bad knees.

  7. In ancestral times people’s sleeping patterns followed the sun, they had no other option until a bit over a century ago.

  8. Sleeping pills are one of the most widely prescribed medications there are which shows that concerns over sleep are very common. A 9-5 job may not conform to someone’s biological clock but that’s pretty much tough luck; people are forced to adjust to that not the other way around. There’s also no siesta time allotted to workers in the US which some might find beneficial. This is what coffee is for. If a person is really sleep deprived it usually catches up to them and they crash out but there’s no point in getting neurotic about it. Since I retired I don’t need to worry about it at all. It takes a while to convince oneself they no longer need to watch the clock. Result is I wake up earlier than when I was working during the summer, later in the winter; it follows the sun. If I feel wide-awake at 3am there’s no need to worry, just get up and do things as though it’s 3pm and then crash out later. Catnaps are not against the law either.

  9. It varies by season with most sleeping less in summer (long day in the north), fructose in the diet is supposed to be a biological signal for summer and putting on fat to last over winter so I wonder if the fructose uric acid connection reduces sleep. A solid eight hours regularly would be well above average for the late middle aged or retired person. The expert quoted is advocating more sleep not just later rising in the morning.

  10. If people aren’t oblivious, why don’t any politicians address it as an issue?

    They did speak to the 8-hour workday; why not the start time? (Mandate paying workers more if they have to start at 8 instead of 11.) Seems the reason is that people aren’t oblivious to the importance of the length of the working day, whereas they are oblivious to the costs of starting at 8.

  11. Since the idea of “day” and “night” is relative to sunrise and sunset, and those vary considerably by latitude and season, why would age-appropriate, universal wake-up times exist or be consistent throughout the year?

    A simpler explanation is that young adults (teens and early 20s) tend to want to sleep-in because they often stay up late studying, socializing, working part-time jobs, etc. Due to their higher rate of metabolism, they’re also likely to have more energy throughout the day than children and older adults and that allows them to stay up later in the first place. And younger teens need more sleep because their bodies are still growing. If they consistently stay up late, their body clock tries to make up their sleep deficit in the morning. There are only so many hours in a night unless you’re in the arctic.

    Mr. Karlin, if you’ve lived in Saint Petersburg, did long summer days and winter nights have any effect on your own sleep habits? I lived for several months at about the same latitude in Anchorage, Alaska, and found that if I could block out the extended twilight, I could go to sleep at a normal time and still get up in the morning. So, I think sleep and wake times are mostly influenced by light and commitment to a daily routine.

    I’m aware of theories that paleo-humans slept sporadically and in shorter blocks of time. But I think there’s a difference between waking up once in a while to tend a fire or sneak off for sex, and waking up several times to check social media. And infants probably sleep in shorter blocks (though much more overall) because their stomachs are small. I don’t think this is potential evidence of ancestral habits or some sort of behavioral orthogenesis.

  12. Do you have kids, Anatoly?

    I used to be a night owl and then I had children. Now I prefer to start the day bright and early and get my work out of the way before the evening. I’m an average sleeper by the way. Seven hours is just right. When I first had to take care of a couple kids alone I found myself so exhausted by the end of the day that I couldn’t stay up any later. I’d put them to bed at 8:30 and then crash within a half hour or so. This allowed me to get up before 5AM, at which point I’d have a couple hours of peace and quiet before all hell broke loose.

    I think being an early riser is a normal consequence of having a family, and it’s why most people like to get started early. If I were still single and childless I’d probably think work should start at 10AM.

  13. Politicians only “spoke to” the eight-hour workday because well organized unions held their soles to the inferno. Workers’ votes used to mean something.

    Automated regimes require humans to tend the machines, and that requires selection for more automation-similar traits. Like being turned on and off when the clock says, not when your body says.

    Most workers now aren’t dealing with, say, automation of spinning and weaving fabric, as my maternal grandmother, great-grandmother, and great-great-grandmother were. Most workers today are dealing with the automation of communication and transportation.

    People “aren’t oblivious to the importance of the length of the working day” because, if you’re sleep deprived, by the three-o-clock-roadblock, two hours is about all they can manage. And then they’re expected to drive themselves home, checking the smartphone the whole way, and then start the family/household/volunteer round.

  14. One reason young people may stay up later is because they have significantly more dopamine receptors. This is a consequence of children’s need to absorb huge amount of information. It’s why toddlers are so energetic and can’t seem to sit still. They literally have the same brain chemistry as a permanently coked-up adulthood.