Introducing chronotype detection

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Introducing chronotype detection

owl

For some reason, the western civilization favors morning people with its predominant 9-to-5 job schedule.
A portion of people is okay with that, a portion is extremely happy about it, and then, well, there’s the night owl.

When we started our big SleepCloud study1 last year, one of the first things we wanted to find out was whether there is any support for the owl/lark hypothesis. Whether night owls and morning larks even exist.

Turns out they do. As with all human classification, the scale from owl to lark is continuous, so there are people who go to sleep strictly at nine, wake up at five, and are happy. There are people who are shifting their sleep patterns. There are nightshifters, not only by profession, but swearing by nightlife.

Night owl person tends to stay up active until late night, usually past midnight, and wake up later. See wikipedia article.
Morning lark person is named after a bird who rises very early in the morning. A human lark is a person who usually gets up early and feels most energetic towards the start of the day. They tend to get tired towards the evening. See wikipedia article.

Also check out our documentation page for Chronotype.

Till Roenneberg, a professor of chronobiology at Ludwig-Maximilian University in Munich, makes an argument in his book Internal Time that people are born with a chronotype. Everyone is somewhere on the spectrum from owl to lark, and this doesn’t change by any external pressures. Not adhering to one’s natural chronotype has severe consequences to the quality of life, especially concerning fatigue and energy levels.

In other words, you might be sleep deprived for your whole life if you are a natural owl doing 9-to-5 office jobs.landscape_framed

Roenneberg has also brought up social jet lag, a notion that when people have a completely free day, they will turn to their natural chronotype (and go wild for the whole night and go to sleep at 6AM and stuff). But when they work a fixed schedule, they have to fight this natural tendency on workdays. This constant shifting of sleep pattern between workdays and weekdays creates a certain tension that can be best compared to a periodic shifting of timezones – and a jet lag results.

c69f6d8a-cfbc-4298-8316-e3db8a949b05In the latest release of Sleep as Android, you can find out what your chronotype is – are you a level 1 lark, or perhaps a hardcore night owl? Sleep as Android will also show your trends – if you are a changeling.

Do you play your part in social jet lag by sleeping differently on weekends than on workdays? You can compare your jet lag to the general population.

Sleep as Android with chronotype detection is in stable release. Get it now!

Get it on Google Play

1. SleepCloud study is an ongoing sleep research by Urbandroid Team, based on sleep records submitted to SleepCloud from users of Sleep as Android app all around the world. Catch up on the SleepCloud study here.

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16 thoughts on “Introducing chronotype detection

      1. Thank you Jiri. I was wondering, a few weeks ago I was a Morning Lark 2, now I’m a Morning Lark 1. What is the difference in these definitions? I’ve had a few mornings when I’ve had to get up earlier recently, so I can guess, but I’didn’t love to know more specifically what the definitions is.

    1. Midsleep hour is the middle hour of your sleep. I.e. sleeping from 10PM to 6AM, midsleep hour would be 2AM.
      This is a nice simple indicator of inclination to one of the two chronotypes.

    1. Hi Brett, we have sectioned the population into 20 groups (Morning Lark 10 to 1, Night Owl 1 to 10) according to their average mid sleep hour (wake up hour – fall asleep hour).
      Morning Lark 2 means that you tend to wake up in the morning, and that your mid sleep hour is deviated from the population average less than 80% of population.
      If you were Morning lark 10, you would be a morning lark with the most midsleep hour deviation from the average.

  1. Hi Brett,
    I am a Morning Lark 3, I used to be a 2.
    I understand that it means that I tend to wake up in the morning, and that my mid sleep hour os 3 am instead of 2.
    But this is the part of the article I don’t understand (maybe it is because English is my second language :/ )
    “is deviated from the population average less than 80% of population.
    If you were Morning lark 10, you would be a morning lark with the most midsleep hour deviation from the average”

    Thank you

    1. Hi Marjorie….I was already sure this part would be incomprehensible when I wrote it 🙂 I’ll try to explain in a human language 🙂

      The scale from Morning lark 5 to Night owl 5 is not absolute, but relative. This means that Morning lark 5 is the person whose midsleep hour most deviates from the population average.

      So for example: let’s say the average mid-sleep hour for all people is 2AM (most people sleep from 10PM to 6AM). Suppose there is a person who goes to sleep at 5AM and wakes up at 11AM. His midsleep hour would be 8AM.
      He would be clearly a night owl, because his midsleep hour is later than the population average.
      However we do not know yet what level Night owl he would be.

      For that, we need to know the distribution of mid-sleep hours in the population. We need to know how many night owls have midsleep hour larger than our guy and how many night owls have it lower. This will establish a relative scale which we then segment into 5 divisions.
      Our midsleep hour will then sit somewhere on the scale. If it’s on the extreme (meaning there is 0-9% people who have the midsleep hour larger), then we are Night owl level 5. If there are 10%-19% of people who have the midsleep hour larger, we are level 4. Etc…

  2. Hi All, just a small clarification. Everything that Jiri wrote above was correct, only the scale of owliness/larkiness ranges from 1 to 5, not 1 to 10. There are 10 categories in total, 5 for larks and 5 for owls.

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