What’s Your Chronotype, And Why Should You Care?

But what is it really?

What is a chronotype?

Most of us are familiar with the old “early bird/night owl” dichotomy – the divide between those of us who are naturally early risers, and those of us who find it much easier to stay up late. Well, it’s not exactly that simple – but, overall, that’s what we mean when we say chronotype.

Now, we often think of this sleepiness/wakefulness pattern as being our own personal circadian rhythm – and that’s kind of correct: “Sleep chronotype is closely related to circadian rhythm, which controls the day-to-day sleep-wake cycle,” says the Sleep Foundation.

But that alone is seriously underselling the true extent of your chronotype’s influence. “In addition to regulating sleep and wake times, chronotype has an influence on appetite, exercise, and core body temperature,” the Sleep Foundation explains. “It is responsible for the fact that you feel more alert at certain periods of the day and sleepier at others.”

Perhaps the most significant difference between a circadian rhythm and a chronotype, though, is how flexible they are. Put simply: circadian rhythms come and go – you can change them incrementally with strict scheduling, or dramatically by moving into a cave for the rest of your life – but your chronotype is fixed. 

At least, more or less. Your chronotype may shift as you age – there’s real truth to the stereotype that teenagers sleep in late and old people get up before sunrise, after all – but overall, it seems there’s not much you can do to force it to change. As best we know, it’s built into the very fabric of your body: “Taken together, heritability estimates suggest that genetic factors explain a considerable proportion, up to 50 percent, of the population variability in circadian timing,” notes one 2017 review. 

And nothing serves to highlight just how different and immutable various chronotypes can be more than how they’re usually classified.

Finding your chronotype

Like pretty much everything in life, chronotypes exist on a spectrum. They’re normally distributed – that is, they follow that bell-shaped curve that governs so much in biology, with very few people waking up before the crack of dawn, very few staying up until then, and most of us existing in between.

That said, everybody likes a personality quiz, and plenty have been invented for the purposes of determining chronotype. You can be classified as either a lark or an owl; an E, M, or N; one of the most popular systems, developed by clinical psychologist Micheal Breus, sorts takers into four animal-based archetypes: the lion, the wolf, the bear, and the dolphin.

So, which animal are you? Well, chances are, you’re a bear: Breus reckons more than half of us fall into this ursine category. “People with this intermediate chronotype tend to follow the sun,” explains the Sleep Foundation. “They do well with traditional office hours but also have no problem maintaining a social life in the evenings.”

Somewhat less widespread, covering around 15 percent of us, is the wolf chronotype. This is basically your standard “night owl” chronotype: you wake up later, stay up later, and you’re at your best in the afternoon and evening. 

Wolves are balanced out by lions, who rise early and get crap done before the wolves are even coherent. “They may easily wake up before dawn,” Eva Cohen, a certified sleep science coach from Kansas-Sleep, told Healthline, “and are at their best up until noon.”

So, after early wakers, late stayer-uppers, and the comfortably in between, what schedule could possibly remain for the last ten or so percent of us? Well, none – and that’s exactly what the last chronotype, the dolphin, has to cope with. Like their cetacean namesake, dolphins are marked by a tendency to still be “on” even while they sleep: they wake easily, and rarely keep a regular sleep schedule.

“[Dolphins] often don’t get enough sleep,” pointed out Cohen, “due to their sensitivity to different disturbing factors like noise and light.” 

When your chronotype works against you

It turns out your chronotype is linked to much more than just how and when you snooze. “Chronotype can also influence attitudes, lifestyle, cognitive function, athletic performance, and personality traits,” explains a 2021 review of chronotype and circadian rhythm research. 

For example, “M-types [early risers] have been suggested to be more conscientious, agreeable, and achievement-oriented,” the paper notes. “In contrast, E-types [late risers] have been indicated to be slightly more extroverted, exhibit neurotic traits, and are more disposed to mental or psychiatric, mood, personality disturbances, and eating disorders.”

At first, that makes it sound like being a late riser is a recipe for disaster – and it kind of is, but not for the reasons you may assume. Society at large revolves around a particular set of temporal touchpoints: we hold down a “nine to five”, for example, not an “eleven to seven”; we’re taught that being “early to bed, early to rise, makes a man healthy, wealthy and wise” rather than, like, “late getting up and late to bed; good for your heart and good for your head”.

Basically, the world is not set up for night owls – and as a result, they’re essentially constantly sleep deprived. No wonder they’re cranky. The same can be true for extreme early risers, too: if you’ve got a friend who always sees the sunrise, but never comes out for drinks after work, it could be that socializing after 8 pm is simply too tiring for them.

“When a person’s natural chronotype comes into conflict with the demands of their schedule, this is termed social jetlag,” explains the Sleep Foundation. “People who have a later chronotype may suffer from social jetlag and feel permanently tired if they need to wake up early for work or school. Likewise, those who prefer to go to bed earlier may not do well with social or cultural activities that are programmed later in the evening.” 

“For both groups, trying to perform activities that require concentration or creativity may be difficult at non-peak times,” it adds.

What should I do about my chronotype?

So, now you know your chronotype – what should you do about it? Well, given that there’s not much you can do to change it, the best thing to do is figure out a way to work with it. “Knowing your chronotype may help you understand how your internal clock works,” Cohen told Healthline, “and how you can synchronize it with your daily activities and duties to use your time most efficiently.”

So, if you have a wolf chronotype, here’s a tip: don’t schedule your downtime for around 6 pm – that’s likely to be one of your peak productivity periods in the day. On the other hand, someone whose chronotype leans leonine should do the opposite; any important jobs should be scheduled before noon, after which your body starts winding down.

Mostly, though, a chronotype is really just a name – one for something you should already know, really: when you feel most tired; when you like to get up; when you’re at your best, or worst. It’s who you are – your natural rhythm of daily life.

So, next time your friend is late for a get-together, or your Tinder match sleeps through your dinner date, don’t worry – it’s not on purpose. It’s just their chronotype.