13 ms·

Night owls have more grey matter in their brains than early birds

211 points by dmitriy_ko 6y ago

henearkr 6y ago
Based on my own night-owl life, I'd suggest that might be because people might be more sensitive to social interaction (thus these interactions being more disruptive), and thus need the calm of the night to pursue their hobbies and readings. Edit: that does not resist deeper analysis: one can as well evade social interactions by studying in the very early morning after getting up.
- mmm_grayons 6y ago
  Inertia usually means it's easier to stay up late than to get up early.
  - ksec 6y ago
    Thank You. That is a nice way to think about it.
  - henearkr 6y ago
    Could even just be that night owls are "people with more inertia".
- smabie 6y ago
  A universal of all primitive/ancient cultures is that they were much more social at night. Hunter-gatherers hunt and gather during the day, and tell stories at night. Early birds get social capital and reproductive access through exploiting hunting opportunities before other people are up. Night owls get social capital and reproductive access through telling cool stories and being popular. It therefore makes sense that being social and being a night owl are correlated.
  - dmonitor 6y ago
    According to the article, being a night owl is correlated with being less social, not more social
    - spideymans 6y ago
      Are they less social because they desire less social interaction, or are they less social because when they're awake they're around fewer people. Possibly critical distinction there. Speaking for myself, I pretty much don't want to communicate with other people before 3 PM, however I'll happily stay up til 6 AM socializing with friends.
Tarsul 6y ago
so they say that having little grey matter (like early birds) correlates with "empathy, agreeableness and cooperation." But maybe early birds are only so empathatic and agreeable because their day/night cycle is not always disrupted by how the world is set up? Whereas us grumpy night owls having a case of a bad monday morning is maybe just because we have to stand up early and don't want to?
- stOneskull 6y ago
  it seems people are nicer in the early morning. getting the milk or newspaper, saying 'good morning' to each other, walking to a nice sunrise and stuff. and it seems that the extra gray matter is like the way people can 'think too much' about things, especially with social stuff. i can see how that also leads to social problems and psychiatric problems, as well as the wanting some peace at night to have a relaxed mind, and that social thinking to be quieter. sounds like social media at night should be avoided.
  - Gravityloss 6y ago
    "The Narrow Land" by Jack Vance kind of dwells on this.
    - stOneskull 6y ago
      i'll find a copy. it's a pretty interesting thing to think about.
- vezycash 6y ago
  This corona virus holiday's given me the opportunity to revert to my preferred working time. It's taken tremendous restraints not to harm those who give me eye/head aches from interrupting my sleep. It's maddening how early risers in my family just can't understand why anyone would stay awake overnight and start their sleep when others are just waking up.
- spideymans 6y ago
  Possibly. Anecdotal, of course, but I pretty much consistently don't want to communicate with anybody before 3 PM, whether in person or digitally. Now late at night, however, I'm a total social animal.
undersuit 6y ago
I thought it was a study about birds and I was confused why they were trying to apply all these human traits in the article. I then came over here and downvoted two commentors for also confusingly talking about birds. I much prefer the original title of the study: Diurnal Preference and Grey Matter Volume in a Large Population of Older Adults: Data from the UK Biobank
- michaelcampbell 6y ago
  The (IMO) bizarre re-titling that this site does boggles me. https://hackernewstitles.netlify.app/ https://hackernewstitles.netlify.app/
  - lucb1e 6y ago
    That's an interesting page. Perhaps off-topic, but I'm never sure where meta can be discussed so I guess a subthread of a subthread might be reasonably out of the way / collapsable. Some of the changes are clearly good: "Article: Learning how to learn (with 20 study references)" was changed into "Learning how to learn" which is indeed what it's about (the article prefix is useless, the "with 20 references" sounds a bit like WikiHow's "with pictures!"). The "google relentlessly continues to attack on X" title was changed to just "google add experimental flag to do X" to make it more objective, also good. But those are the minority: another titles was first edited to change "54" into "fifty four" (how's that useful?) and then edited again to omit the number altogether (how is that more helpful to the reader?). The "CDC denies tribes" title was changed to not mention the CDC at all, now the tribes are simply "thwarted" (hiding info, why? AFAICT nobody else was involved in the thwarting). The interview date "May 2020" was removed (helpful how?). "My daughter and I made a site to explore the ~3.5M photos from the ISS" was edited to remove the 3.5M number (just why?)... Not even the author can edit a title iirc, this is all needless moderation at best or harmful at worst.
    - fphhotchips 6y ago
      How many of those 'useless' edits were changing the title back to whatever the actual page title was? Keep in mind that sometimes site owners change or A/B test page titles.
pram 6y ago
Checks out. I stay up all night and don’t like talking to people. Guess my brain is fat.
DaiPlusPlus 6y ago
I’m certifiably a night-owl and definitely not a morning-person (to the point where I employ licensed caregivers to yell at me in the morning - my psychologist recommended it!) - but I wouldn’t attribute it in any way to being “social” - for some reason I just find it significantly easier to be focused, motivated, and productive after 6pm than any time before. I used to attribute it to my horrible procrastination and how only in the night before a school or uni homework deadline I’d crank something out out of desperation, but it’s still an ongoing habit with my current day-job (er... night-job?) where deadlines aren’t really a thing (I love my boss) but I still feel most-productive in the evenings. I’m ASD+ADHD[1] too - and I see similar things with other people I know with similar diagnoses. I believe they’re all related. [1]: I really dislike the “ADHD” label because I’m not hyperactive in any way - or resemble stereotypical symptoms - if I could rename whatever it is I’ve got I’d call it “Motivation deficit” or similar.
- OriginalPenguin 6y ago
  You employ licensed caregivers to yell at you in the morning? Can you explain more? Are you implying you are paying a nurse to open your door and yell at you "get out of bed sleepyhead?" Or is your insurance paying? Do they actually drive to your house and do this? Do they do anything else for you?
  - DaiPlusPlus 6y ago
    > You employ licensed caregivers to yell at you in the morning? Yes. I use sites like Care.com and WellBeyondCare.com to find them. > Are you implying you are paying a nurse to open your door and yell at you "get out of bed sleepyhead?" They aren’t nurses. The going rate for a caregiver in the US is only slightly above minimum-wage which is awful - especially considering the “human” value of the work they do for us and our loved-ones. > Or is your insurance paying? I pay for it myself. A good chunk of my income is 1099-based and my CPA said I can deduct my caregiving expenses as a business expense because without their help I wouldn’t be working anywhere near as many hours as I do otherwise. I pay them $30-35/hr - with a 1-hour minimum. They pay for themselves as far as I’m concerned. > Do they actually drive to your house and do this? Yes. They come-by around 6-7am and spend about 15-30 minutes with me before they go off to their main day job, so I imagine it’s a nice little (easy!) side-gig for them. > Do they do anything else for you? I’ve had a few that stayed for a full hour - they’d make me a proper cooked breakfast while I’m spending 20+ minutes just waking up in the shower. ...it’s like living with my parents again. My generation likes to joke about “bed gravity” but it’s a real problem :/
trophycase 6y ago
Correlation or causation? Do people that get up earlier have to work more? Possibly live in more difficult conditions? Maybe are more addicted to caffeine? Just kinda spitballing here.
- 6510 6y ago
  Cheap beds increase grey matter
dpenguin 6y ago
Just woke up. Totally agree with this article, even though it was published 4 hours ago in the early hours of the morning!
cbanek 6y ago
> Eveningness, meanwhile, has previously been shown to be associated with an increased risk of psychiatric disorders and personality traits such a neuroticism. Hey, I resemble that remark. I think it's also interesting that it's _more_ grey matter that causes it, usually I think I hear of many brain issues coming from a lack of matter or deterioration in an area.
seesawtron 6y ago
It is to be noted that they found "evening types" people had greater grey matter volume in an area of the brain called the precuneus, NOT in the whole brain. Also it is not clear whether more grey matter makes the individuals "evening types" or the other way around. This study does not discuss that. So jumping to theories about personality traits seems quite far fetched. Evening types were younger than morning types in their sample of studied people. It is known that there is a decrease in grey matter volume between adulthood and old age, whereas white matter volume was found to increase from age 19-40, and decline after this age (Bartzokis et al.). So it is not surprising that their data showed evening types (younger people) had higher grey matter than morning types (older people).
- adjkant 6y ago
  All of this seems fair, so an interesting note off of this: I find the causality/correlative arrow here interesting as no matter the direction, there is interesting insight.
  - seesawtron 6y ago
    That would be interesting but I am not sure if this study is solid to even show existence of this arrow. That assumes that there are no confounding variables but just a one directional arrow either way. However several confounding variables likely exist (maybe age, maybe more things we haven't thought about) that could give rise to reduction in gray matter, change in sleeping patterns, so on and so forth. Since this is not a behavioral study where experimentalists can actually control for confounding factors (like in animal studies), this correlation/causation arrow likely is a spurious observable effect. An ideal experiment would involve studying say lab animals in a controlled setting where "everything else being equal" one group sleeps during day and other during night and then observe their gray matter. Perhaps similar studies already exist but this paper doesn't refer to anything.
- strbean 6y ago
  Mean age for morning types was ~56, for evening types it was ~54. Seems unlikely that changing grey matter volume with age is explanatory here.
rajansaini 6y ago
Here is an interesting point for discussion that I hope others may chime in on. What is the difference between being a night owl and experiencing jet lag? With enough discipline, one can recover from jet lag in a matter of days. Why then do some people believe themselves condemned to be a night owl or early bird?
- thisiszilff 6y ago
  For me at least I can train myself to go to bed at 10PM with discipline, but if I miss one day I find myself back into the natural groove of going to bed at 2AM. I do not expend effort to sleep at 2AM, I expend effort to sleep at 10PM. When I am jet lagged my body is confused and does not quite know when 2AM is, but eventually it figures it out and we're back to square one (Google "zeitgeber" for how it figures this out, but subjectively I assure you my body does the adjusting, not me).
- colemak_throw 6y ago
  This is a great question, and I wish more people were interested in how the biological clock works. As a night owl, you basically get jet lag every day. Jet lag means that your internal, biological clock is still adjusted to the sunrise/sundown times of another time zone, because you traveled faster than about 1 hour of timezone difference per day, i.e. per jet - that's why it's called jet lag. There is no discipline to recovering from jet lag. Depending on the direction and the personal biological clock (they're all slightly different) it takes roughly 1 day to recover 1 hour of jet lag. So the craziest you can get is 12 hours off, which will take a week and a half to recover from. Imagine your internal clock like a clock that you can only change the time on by about an hour per day. If you bring it to a timezone 3 hours away, you'll need to turn it by 1 hour for 3 days in a row. "Easy" jet lag (e.g. US coast to coast) is about 3 hours, and so will only take a few days. Plus, you can miss 1-2 hours of sleep for one night and not feel that different - so it's easy to "power through" or not notice the jet lag. Longer jet lags, like from traveling from the US to Asia, will be much more noticeable, and will often take a week or even longer to recover from. This is where you get people waking up at 2am unable to get back to sleep, and drop like a rock when the afternoon comes around. It is slightly easier for most people to delay their sleep than to pull it forward, because the typical person's circadian rhythm is a bit longer than 24 hours. So flying from the East Coast to the West Coast results in slightly less jet lag than the other way around for most people, or at least they're able to recover slightly faster. For night owls, if they would usually wake up at 10am and the sun comes up at 6am where they live, but really they have to wake up at 8am, they basically have a 2 hour jet lag every day. It's as if they're flying across 2 time zones every day. This night owl will never "recover," because there isn't typically ever a sunrise at 4am at the place, which would trigger that person's circadian rhythm to wake up at 8am. You can try using tricks like light boxes (very powerful lights) to simulate the sunrise, but most commercial models are not particularly effective. I can move my rhythm about 30 minutes forward using a commercial light box. But it gives me headaches, which I don't get from the sun. There was a post recently here on HN where somebody built his own, very bright light simulator by using LED strips. These were about 5x more powerful than the commercial light boxes, if I remember it right. He was using it to treat seasonal depression in the winter, but it should work for adjusting the circadian rhythm as well. So these people don't just "believe" themselves to be condemned to being a night owl or early bird. It is relative to the sun, and it is malleable to a degree, but only to a degree.
SubiculumCode 6y ago
Not a fan of Voxel Based Morphometry, personally.
gpsx 6y ago
I have been taking my temperature every day, maybe a few times a day for over a month. I was just curious to see how helpful this is related to COVID-19. Anyway, what I did see, for what it is worth, was my temperature change by a lot over the course of a day, by over a degree. And I can guess what my temperature will be based on how energetic I feel. I am not a morning person and the temperature is higher later in the day, peaking from around 3:00 PM to 7:00 PM. It returns to around the wakeup temperature at maybe 11:00 PM or midnight. I am guess the temperature profile for a morning person would look different.
bondolo 6y ago
Not all of it is without choice. I used to be a night owl. I woke around 10am, worked from 11am until 1am or sometimes later. The invariant was that I generally slept between 9-10 hours. I also suffered from seasonal affective disorder and winter time depression with short days in Canada. To help with this I started spending time outside during the early part of the day and generally ate my lunch outside if possible. This helped somewhat. This switch to prioritizing sunlight exposure also made me consider that sleeping while the sun was up and working in the dark was a strange choice. For more than the last 25 years I've intentionally time shifted to ensure that I don't waste daylight hours sleeping. If I'd follow my natural sleep rhythms I'd almost surely drift later, I'd we waking several hours after sunrise and working in to the evening. Even though I have to have some discipline about using an alarm clock and only allowing myself 1 day a week to wake naturally it is not actually that hard because I do it consistently. I could also easily stay up late one night, but getting up at the same time every day makes staying up harder. My intentional time shifting isn't that dramatic of a "hacking" of my natural inclination. It has made a difference with seasonal depression and I've found that social activity works better with a time schedule aligned to daylight hours. It is easy to read a study like this and conclude that personal choice plays no part in determining your "fate". You have some flexibility and choice to do what you need to do. An inclination is not an outcome.
- Godel_unicode 6y ago
  Your experience is not the same as many other people's. There are tons of cases of people who perform markedly worse when they have to get up earlier, even if they're getting enough sleep. This is a choice for some people. It's not for others.
- collyw 6y ago
  I am the same, I will naturally go to bed late and get up late, but unfortunately the world doesn't revolve around my schedule, so I make a point of trying to have decent sleep hygiene and going to bed early enough to allow me a decent amount of sleep.
m463 6y ago
I sort of suspect the way to become a night owl is to get enough sleep.
deleted 6y ago
[deleted]
russellbeattie 6y ago
"We also know that reduced volume in this area has been associated with empathy, agreeableness and cooperation, so it ties nicely with behavioural data that suggests early chronotypes tend to engage in more pro-social behaviours than evening types." As a night owl, I hate when generic observations are made about us. I hate it even more when they're backed by scientific research and fit perfectly.
- zzo38computer 6y ago
  Even though I am also a late chronotype too (I don't like calling it "night owl" if you are not a owl though, because I am not a owl), I don't hate it when stuff is backed by scientific research; I think is better that way, rather than making accusations which have not ben scientifically tested.
collyw 6y ago
Cue lots of self congratulatory facebook posts.

211 points by dmitriy_ko 6y ago

Based on my own night-owl life, I'd suggest that might be because people might be more sensitive to social interaction (thus these interactions being more disruptive), and thus need the calm of the night to pursue their hobbies and readings. Edit: that does not resist deeper analysis: one can as well evade social interactions by studying in the very early morning after getting up.

mmm_grayons 6y ago
Inertia usually means it's easier to stay up late than to get up early.
- ksec 6y ago
  Thank You. That is a nice way to think about it.
- henearkr 6y ago
  Could even just be that night owls are "people with more inertia".
smabie 6y ago
A universal of all primitive/ancient cultures is that they were much more social at night. Hunter-gatherers hunt and gather during the day, and tell stories at night. Early birds get social capital and reproductive access through exploiting hunting opportunities before other people are up. Night owls get social capital and reproductive access through telling cool stories and being popular. It therefore makes sense that being social and being a night owl are correlated.
- dmonitor 6y ago
  According to the article, being a night owl is correlated with being less social, not more social
  - spideymans 6y ago
    Are they less social because they desire less social interaction, or are they less social because when they're awake they're around fewer people. Possibly critical distinction there. Speaking for myself, I pretty much don't want to communicate with other people before 3 PM, however I'll happily stay up til 6 AM socializing with friends.

Tarsul 6y ago

so they say that having little grey matter (like early birds) correlates with "empathy, agreeableness and cooperation." But maybe early birds are only so empathatic and agreeable because their day/night cycle is not always disrupted by how the world is set up? Whereas us grumpy night owls having a case of a bad monday morning is maybe just because we have to stand up early and don't want to?

stOneskull 6y ago
it seems people are nicer in the early morning. getting the milk or newspaper, saying 'good morning' to each other, walking to a nice sunrise and stuff. and it seems that the extra gray matter is like the way people can 'think too much' about things, especially with social stuff. i can see how that also leads to social problems and psychiatric problems, as well as the wanting some peace at night to have a relaxed mind, and that social thinking to be quieter. sounds like social media at night should be avoided.
- Gravityloss 6y ago
  "The Narrow Land" by Jack Vance kind of dwells on this.
  - stOneskull 6y ago
    i'll find a copy. it's a pretty interesting thing to think about.
vezycash 6y ago
This corona virus holiday's given me the opportunity to revert to my preferred working time. It's taken tremendous restraints not to harm those who give me eye/head aches from interrupting my sleep. It's maddening how early risers in my family just can't understand why anyone would stay awake overnight and start their sleep when others are just waking up.
spideymans 6y ago
Possibly. Anecdotal, of course, but I pretty much consistently don't want to communicate with anybody before 3 PM, whether in person or digitally. Now late at night, however, I'm a total social animal.

undersuit 6y ago

I thought it was a study about birds and I was confused why they were trying to apply all these human traits in the article. I then came over here and downvoted two commentors for also confusingly talking about birds. I much prefer the original title of the study: Diurnal Preference and Grey Matter Volume in a Large Population of Older Adults: Data from the UK Biobank

michaelcampbell 6y ago
The (IMO) bizarre re-titling that this site does boggles me. https://hackernewstitles.netlify.app/ https://hackernewstitles.netlify.app/
- lucb1e 6y ago
  That's an interesting page. Perhaps off-topic, but I'm never sure where meta can be discussed so I guess a subthread of a subthread might be reasonably out of the way / collapsable. Some of the changes are clearly good: "Article: Learning how to learn (with 20 study references)" was changed into "Learning how to learn" which is indeed what it's about (the article prefix is useless, the "with 20 references" sounds a bit like WikiHow's "with pictures!"). The "google relentlessly continues to attack on X" title was changed to just "google add experimental flag to do X" to make it more objective, also good. But those are the minority: another titles was first edited to change "54" into "fifty four" (how's that useful?) and then edited again to omit the number altogether (how is that more helpful to the reader?). The "CDC denies tribes" title was changed to not mention the CDC at all, now the tribes are simply "thwarted" (hiding info, why? AFAICT nobody else was involved in the thwarting). The interview date "May 2020" was removed (helpful how?). "My daughter and I made a site to explore the ~3.5M photos from the ISS" was edited to remove the 3.5M number (just why?)... Not even the author can edit a title iirc, this is all needless moderation at best or harmful at worst.
  - fphhotchips 6y ago
    How many of those 'useless' edits were changing the title back to whatever the actual page title was? Keep in mind that sometimes site owners change or A/B test page titles.

pram 6y ago

Checks out. I stay up all night and don’t like talking to people. Guess my brain is fat.

DaiPlusPlus 6y ago

I’m certifiably a night-owl and definitely not a morning-person (to the point where I employ licensed caregivers to yell at me in the morning - my psychologist recommended it!) - but I wouldn’t attribute it in any way to being “social” - for some reason I just find it significantly easier to be focused, motivated, and productive after 6pm than any time before. I used to attribute it to my horrible procrastination and how only in the night before a school or uni homework deadline I’d crank something out out of desperation, but it’s still an ongoing habit with my current day-job (er... night-job?) where deadlines aren’t really a thing (I love my boss) but I still feel most-productive in the evenings. I’m ASD+ADHD[1] too - and I see similar things with other people I know with similar diagnoses. I believe they’re all related. [1]: I really dislike the “ADHD” label because I’m not hyperactive in any way - or resemble stereotypical symptoms - if I could rename whatever it is I’ve got I’d call it “Motivation deficit” or similar.

OriginalPenguin 6y ago
You employ licensed caregivers to yell at you in the morning? Can you explain more? Are you implying you are paying a nurse to open your door and yell at you "get out of bed sleepyhead?" Or is your insurance paying? Do they actually drive to your house and do this? Do they do anything else for you?
- DaiPlusPlus 6y ago
  > You employ licensed caregivers to yell at you in the morning? Yes. I use sites like Care.com and WellBeyondCare.com to find them. > Are you implying you are paying a nurse to open your door and yell at you "get out of bed sleepyhead?" They aren’t nurses. The going rate for a caregiver in the US is only slightly above minimum-wage which is awful - especially considering the “human” value of the work they do for us and our loved-ones. > Or is your insurance paying? I pay for it myself. A good chunk of my income is 1099-based and my CPA said I can deduct my caregiving expenses as a business expense because without their help I wouldn’t be working anywhere near as many hours as I do otherwise. I pay them $30-35/hr - with a 1-hour minimum. They pay for themselves as far as I’m concerned. > Do they actually drive to your house and do this? Yes. They come-by around 6-7am and spend about 15-30 minutes with me before they go off to their main day job, so I imagine it’s a nice little (easy!) side-gig for them. > Do they do anything else for you? I’ve had a few that stayed for a full hour - they’d make me a proper cooked breakfast while I’m spending 20+ minutes just waking up in the shower. ...it’s like living with my parents again. My generation likes to joke about “bed gravity” but it’s a real problem :/

trophycase 6y ago

Correlation or causation? Do people that get up earlier have to work more? Possibly live in more difficult conditions? Maybe are more addicted to caffeine? Just kinda spitballing here.

6510 6y ago
Cheap beds increase grey matter

dpenguin 6y ago

Just woke up. Totally agree with this article, even though it was published 4 hours ago in the early hours of the morning!

cbanek 6y ago

> Eveningness, meanwhile, has previously been shown to be associated with an increased risk of psychiatric disorders and personality traits such a neuroticism. Hey, I resemble that remark. I think it's also interesting that it's _more_ grey matter that causes it, usually I think I hear of many brain issues coming from a lack of matter or deterioration in an area.

seesawtron 6y ago

It is to be noted that they found "evening types" people had greater grey matter volume in an area of the brain called the precuneus, NOT in the whole brain. Also it is not clear whether more grey matter makes the individuals "evening types" or the other way around. This study does not discuss that. So jumping to theories about personality traits seems quite far fetched. Evening types were younger than morning types in their sample of studied people. It is known that there is a decrease in grey matter volume between adulthood and old age, whereas white matter volume was found to increase from age 19-40, and decline after this age (Bartzokis et al.). So it is not surprising that their data showed evening types (younger people) had higher grey matter than morning types (older people).

adjkant 6y ago
All of this seems fair, so an interesting note off of this: I find the causality/correlative arrow here interesting as no matter the direction, there is interesting insight.
- seesawtron 6y ago
  That would be interesting but I am not sure if this study is solid to even show existence of this arrow. That assumes that there are no confounding variables but just a one directional arrow either way. However several confounding variables likely exist (maybe age, maybe more things we haven't thought about) that could give rise to reduction in gray matter, change in sleeping patterns, so on and so forth. Since this is not a behavioral study where experimentalists can actually control for confounding factors (like in animal studies), this correlation/causation arrow likely is a spurious observable effect. An ideal experiment would involve studying say lab animals in a controlled setting where "everything else being equal" one group sleeps during day and other during night and then observe their gray matter. Perhaps similar studies already exist but this paper doesn't refer to anything.
strbean 6y ago
Mean age for morning types was ~56, for evening types it was ~54. Seems unlikely that changing grey matter volume with age is explanatory here.

rajansaini 6y ago

Here is an interesting point for discussion that I hope others may chime in on. What is the difference between being a night owl and experiencing jet lag? With enough discipline, one can recover from jet lag in a matter of days. Why then do some people believe themselves condemned to be a night owl or early bird?

thisiszilff 6y ago
For me at least I can train myself to go to bed at 10PM with discipline, but if I miss one day I find myself back into the natural groove of going to bed at 2AM. I do not expend effort to sleep at 2AM, I expend effort to sleep at 10PM. When I am jet lagged my body is confused and does not quite know when 2AM is, but eventually it figures it out and we're back to square one (Google "zeitgeber" for how it figures this out, but subjectively I assure you my body does the adjusting, not me).
colemak_throw 6y ago
This is a great question, and I wish more people were interested in how the biological clock works. As a night owl, you basically get jet lag every day. Jet lag means that your internal, biological clock is still adjusted to the sunrise/sundown times of another time zone, because you traveled faster than about 1 hour of timezone difference per day, i.e. per jet - that's why it's called jet lag. There is no discipline to recovering from jet lag. Depending on the direction and the personal biological clock (they're all slightly different) it takes roughly 1 day to recover 1 hour of jet lag. So the craziest you can get is 12 hours off, which will take a week and a half to recover from. Imagine your internal clock like a clock that you can only change the time on by about an hour per day. If you bring it to a timezone 3 hours away, you'll need to turn it by 1 hour for 3 days in a row. "Easy" jet lag (e.g. US coast to coast) is about 3 hours, and so will only take a few days. Plus, you can miss 1-2 hours of sleep for one night and not feel that different - so it's easy to "power through" or not notice the jet lag. Longer jet lags, like from traveling from the US to Asia, will be much more noticeable, and will often take a week or even longer to recover from. This is where you get people waking up at 2am unable to get back to sleep, and drop like a rock when the afternoon comes around. It is slightly easier for most people to delay their sleep than to pull it forward, because the typical person's circadian rhythm is a bit longer than 24 hours. So flying from the East Coast to the West Coast results in slightly less jet lag than the other way around for most people, or at least they're able to recover slightly faster. For night owls, if they would usually wake up at 10am and the sun comes up at 6am where they live, but really they have to wake up at 8am, they basically have a 2 hour jet lag every day. It's as if they're flying across 2 time zones every day. This night owl will never "recover," because there isn't typically ever a sunrise at 4am at the place, which would trigger that person's circadian rhythm to wake up at 8am. You can try using tricks like light boxes (very powerful lights) to simulate the sunrise, but most commercial models are not particularly effective. I can move my rhythm about 30 minutes forward using a commercial light box. But it gives me headaches, which I don't get from the sun. There was a post recently here on HN where somebody built his own, very bright light simulator by using LED strips. These were about 5x more powerful than the commercial light boxes, if I remember it right. He was using it to treat seasonal depression in the winter, but it should work for adjusting the circadian rhythm as well. So these people don't just "believe" themselves to be condemned to being a night owl or early bird. It is relative to the sun, and it is malleable to a degree, but only to a degree.

SubiculumCode 6y ago

Not a fan of Voxel Based Morphometry, personally.

gpsx 6y ago

I have been taking my temperature every day, maybe a few times a day for over a month. I was just curious to see how helpful this is related to COVID-19. Anyway, what I did see, for what it is worth, was my temperature change by a lot over the course of a day, by over a degree. And I can guess what my temperature will be based on how energetic I feel. I am not a morning person and the temperature is higher later in the day, peaking from around 3:00 PM to 7:00 PM. It returns to around the wakeup temperature at maybe 11:00 PM or midnight. I am guess the temperature profile for a morning person would look different.

bondolo 6y ago

Not all of it is without choice. I used to be a night owl. I woke around 10am, worked from 11am until 1am or sometimes later. The invariant was that I generally slept between 9-10 hours. I also suffered from seasonal affective disorder and winter time depression with short days in Canada. To help with this I started spending time outside during the early part of the day and generally ate my lunch outside if possible. This helped somewhat. This switch to prioritizing sunlight exposure also made me consider that sleeping while the sun was up and working in the dark was a strange choice. For more than the last 25 years I've intentionally time shifted to ensure that I don't waste daylight hours sleeping. If I'd follow my natural sleep rhythms I'd almost surely drift later, I'd we waking several hours after sunrise and working in to the evening. Even though I have to have some discipline about using an alarm clock and only allowing myself 1 day a week to wake naturally it is not actually that hard because I do it consistently. I could also easily stay up late one night, but getting up at the same time every day makes staying up harder. My intentional time shifting isn't that dramatic of a "hacking" of my natural inclination. It has made a difference with seasonal depression and I've found that social activity works better with a time schedule aligned to daylight hours. It is easy to read a study like this and conclude that personal choice plays no part in determining your "fate". You have some flexibility and choice to do what you need to do. An inclination is not an outcome.

Godel_unicode 6y ago
Your experience is not the same as many other people's. There are tons of cases of people who perform markedly worse when they have to get up earlier, even if they're getting enough sleep. This is a choice for some people. It's not for others.
collyw 6y ago
I am the same, I will naturally go to bed late and get up late, but unfortunately the world doesn't revolve around my schedule, so I make a point of trying to have decent sleep hygiene and going to bed early enough to allow me a decent amount of sleep.

m463 6y ago

I sort of suspect the way to become a night owl is to get enough sleep.

deleted 6y ago

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russellbeattie 6y ago

"We also know that reduced volume in this area has been associated with empathy, agreeableness and cooperation, so it ties nicely with behavioural data that suggests early chronotypes tend to engage in more pro-social behaviours than evening types." As a night owl, I hate when generic observations are made about us. I hate it even more when they're backed by scientific research and fit perfectly.

zzo38computer 6y ago
Even though I am also a late chronotype too (I don't like calling it "night owl" if you are not a owl though, because I am not a owl), I don't hate it when stuff is backed by scientific research; I think is better that way, rather than making accusations which have not ben scientifically tested.

collyw 6y ago

Cue lots of self congratulatory facebook posts.