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Sleep types & their characteristics: Owl or lark?

Different sleep types? What is this all about? What may sound like hocus-pocus at first is actually based on a separate branch of science that only deals with the temporal organisation of physical processes: chronobiology. Based on various findings, you can understand which sleep type you belong to, why you are particularly efficient early in the morning or late in the evening and which lifestyle is best for you.

by CALIDA

22 November 2023 • 6 min reading time

Two women look into the camera wearing Calida nightwear from the 'Elegant Dreams' series.

Sleep is individual - find out what type of sleeper you are and how you can improve your sleep quality.

What are sleep types and which sleep type am I?

Maybe you are still wondering what exactly sleep types are all about. It’s not about whether you sleep with or without a night light or whether you prefer a hard or a soft mattress. Instead, sleep types are differentiated according to the natural times at which people fall asleep and get up, e.g. their individual biorhythm. It varies from person to person when they are fully rested and ready for the day without an alarm clock and when their internal clock makes them tired and sleepy again in the evening.

General tiredness also plays a role, which occurs constantly during the day in some people, but hardly ever in others. We distinguish between the sleep types owl, lark, bear and dolphin as well as the three chronotypes late, intermediate and early.

The owl / the wolf: Productive until late at night

The owl is a nocturnal animal that barely wakes up in the morning. It’s not for nothing that people who are productive late into the night are described as night owls. This image was reinforced by the German psychiatrist Emil Kraeplin. He distinguished between the nocturnal owl and the lark – a bird that chirps cheerfully early in the morning and greets the world with the sunrise.

The wolf is a similar nocturnal animal to the owl. This chronotype, like the lion, the bear and the dolphin, was developed by the clinical psychologist Michael Breus. As one of the world’s best-known sleep physicians, he was able to find two further nuances to the owl and the lark: the bear and the dolphin. However, his wolf is the equivalent of Kraeplin’s sleeping owl.

The lark / the lion: The early bird catches the worm

The chronotype lark developed by Kraeplin and the lion by Breus are the counterpart to the owl. This chronotype is often completely fit and well-rested by 5 or 6 o’clock in the morning. No sign of a morning grouch!

The advantage: Depending on their job, larks are often finished with their work and household chores before lunch. This gives them more time in the afternoon for hobbies and social interactions. The disadvantage: At evening events, larks are often less energetic than wolves or owls. If they turn up to a party at all, they are often back home and in the land of dreams before midnight.

The bear: Enough sleep? No such thing!

As already mentioned, in addition to the early riser lion and the night owl wolf, the sleep physician Breus has identified two other chronotypes that differ according to their general need for sleep: the bear and the dolphin.

The bear is a very cosy animal that could actually sleep all the time. The bear sleep type also often feels tired and exhausted. It usually starts the day as a morning grouch, then has a productive phase at lunchtime, which is quickly followed by another low in the afternoon. Even in the evening, the bear isn’t fit for long and therefore goes to bed early if possible.

Although you might think that the bear sleep type tends to withdraw and avoid social interactions due to its constant tiredness, the opposite is actually the case. The bear is considered to be a very social, well-mannered and friendly creature – at least until it gets tired.

The dolphin: Always on air

People with the dolphin sleep type are also considered friendly contemporaries, but their tendency to be overzealous and perfectionist can also cause offence. Unlike the cosy bear, the dolphin is a real doer – at any time of day or night. Dolphins are often workaholics, which, coupled with their intelligence, makes them absolute careerists.

While they can work from early in the morning until late at night, there is a shortcoming in their sleeping behaviour: The dolphin sleep type often finds it difficult to rest. Like real dolphins, the sleep type is always awake with one eye and is startled out of sleep at night by any noise. Afterwards, it’s usually difficult for them to fall asleep again, which can lead to chronic sleep deprivation.

Differentiation into chronotypes: Early, intermediate and late type

Talking about wolves and bears in chronobiology may seem somewhat dubious. In the scientific field, a distinction is therefore made between three chronotypes: the early type, the intermediate type, and the late type. As you can probably already guess, this is about natural wake-up and bedtime.

While the early type starts their day at around 5 am and finishes at 10 pm, the late type is awake between 9 am and 1 am. The intermediate type describes the mean value, i.e. waking up between 7 and 7.30 am and going to bed between 11 and 11.30 pm. Around 60 to 70 % of all people belong to the latter type.

Why are there different sleep types?

While some people are always thriving early in the morning, others could sleep for another five hours. But why do we humans tick so differently when it comes to bedtimes and biorhythm? This is probably due to several things. If you take a long look back in human history, it becomes clear: Even Stone Age people couldn’t all sleep at the same time. Especially at dawn and dusk and at night, there always had to be someone on watch to alert the sleeping group to lurking dangers. This may have been passed down in our genes to this day. The reason for being awake during the day is quite simply the brightness. Logically, people didn’t go out to gather food in the dangerous darkness, but in daylight.

In general, our physical sensations, including tiredness, are strongly dependent on hormones. As certain hormonal characteristics are also partly inherited, our natural biorhythm is often similar to that of our parents. This also has something to do with the fact that we learn our sleep behaviour from childhood and unconsciously internalise it. Did your parents celebrate sleeping in late at the weekend back then? Then you probably won’t feel any different today. Did your parents always get up early on holidays to get as much out of the day as possible? Then it’s not surprising if you are a lark or a dolphin sleep type.

Which sleep type is the best?

All sleep types have their advantages and disadvantages. We have already discussed some of them. While the bear, for example, has no problems sleeping in unfamiliar environments such as when travelling, the dolphin can only fall asleep in a familiar bed with the right mattress firmness. During the day, however, they are usually more productive and receptive due to their alertness, whereas the bear is a real daydreamer and should make the most of their few concentrated moments during the day.

The lark is also very productive as an early riser and has already completed its tasks early in the day. It gets tired all the more quickly in the evening and often has to turn its back on social events early. This can seem stuffy to some – especially to people with the owl sleep type. While others relax after 8 pm, owls use the night to get out or even get some work done. In the morning, they sleep all the longer – and unfortunately, this biorhythm has some disadvantages.

Less daylight, more sleep deprivation: The disadvantages for late risers

It’s probably impossible to say exactly which sleep type is the best. This always depends on personal preferences and your own work and life rhythm. If the lifestyle fits in with the natural times for getting up and going to bed, all is well. If this is not the case, you should change something – either your sleeping times or, better still, your living conditions. Because living against your natural biorhythm can be very unhealthy in the long term.

From a health point of view, being a late riser generally has some disadvantages. This is mainly due to the fact that the owl sleep type sees significantly less daylight. Because while the lark gets up with the sunrise and goes to bed shortly after sunset, the owl misses out on some valuable hours of sunshine in the morning. This can lead to a lower release of the happiness hormone serotonin and thus to an increased likelihood of developing depression.

In addition, owls often sleep less late, as many people have to get up early in the morning due to work or children. Chronic sleep deprivation can lead not only to depression, but also to concentration problems and clouding of perception. In this case, owls and bears should make changes to their daily routines and processes in order to be more productive, more receptive and happier again.

Sleep types can change over time

Just as hormone concentrations change over the course of a lifetime, sleeping habits can also change. Especially during puberty, teenagers suddenly want to sleep much longer than they did as children. Later on, they often become early risers again; by the mid-20s at the latest, the sleep type has stabilised. Now you know whether you are a late or an early riser, a heavy or a light sleeper or something in between.

But what if your sleep type doesn’t match your life with work, children, appointments and such? Can you change your own sleep type?

Can I change my sleep type?

Changing your own sleep type is only possible to a limited extend. Sure, as an owl, you can try to go to bed earlier so that you are less exhausted in the morning. However, this change doesn’t turn you into a lark, especially as it often seems almost impossible for owls and bears to fall asleep earlier. It isn’t for nothing that biorhythms are referred to as natural sleep behaviour – and this can’t be changed by external, “artificial” factors.

Experts therefore recommend not trying to change your sleep type, but rather to organise your life according to your individual biorhythm. This applies to both career and partner choices. In fact, it’s ideal if your partner has a different sleep type than you. With children in particular, this is the ideal way to divide up the various tasks that depend on getting up early or looking after them at night.


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