Night owls get a bad rap. They’re seen as lazy and unmotivated, but that’s definitely not the case. Instead, the body’s internal clock and genetics play a huge role in determining whether you’re an early bird or a night owl. 

Nonetheless, night owls are forced to keep up with early risers, and this puts them at risk for being more sleep deprived than others. So, here’s what you need to know about night owls and why it’s time to stop shaming them.

Your circadian rhythm explained

There are two main factors that determine when you want to sleep and when you want to be awake. One is your internal 24 hour clock, called the circadian rhythm. And the other is a chemical substance, called adenosine. Today, we’re talking about the circadian rhythm and how it impacts night owls and early birds.

What is circadian rhythm?

The word “circadian” comes from two latin words, “Circa” meaning, “about” or “approximately”, and “dian”, which comes from the word, “diam” or “day”.

So, your circadian rhythm means “approximately a day” and it’s roughly 24 hours long. 

The cool thing about circadian rhythm is that even though it’s approximately 24 hours long, every one has their own unique, internal rhythm. 

Why the circadian rhythm is “approximately” 24 hours

It seems like the circadian rhythm is based around the sun. After all, we’re awake when there’s daylight and asleep when it’s dark. But it’s not that simple. 

In fact, our circadian rhythm is it’s own internal clock, not dependent on external cues like the sunlight. 

How do we know this? Back in the 1930s, Chicago University professor Nathaniel Kleitman and graduate student, Bruce Richardson, travelled to one of the deepest caverns on earth – the Mammoth Cave in Kentucky. 

Sunlight doesn’t reach deep within the cave, and these two researchers lived there for six weeks. Why?

They wanted to see what would happen to their circadian rhythms when they removed outside cues, like daylight.

At the end of their dark six weeks, Kleitman and Richardson discovered that despite zero sunlight, their bodies kept generating a predictable and regular circadian rhythm for both sleep and wakefulness times.

During this experiment, they also found that their own circadian rhythms were a bit longer than 24 hours – somewhere in between 24 and 28 hours.

In short, without sunlight, our internal clocks tend to be a little longer than 24 hours. But they are continue to be regular and predictable. 

Why everyone has their own unique circadian rhythm

Even though circadian rhythm regulates our wake and sleep times, that doesn’t mean it’s the same rhythm for every single person. 

For one thing, it works independently of the sun. And for another thing, if we had it our way, our circadian rhythms would be “about” 24 hours, but not exactly 24 hours. 

After all, if we were all operating under the exact same circadian rhythm, we’d all wake up with the sun and go to bed with the sunset. 

But that’s not the case is it? Some of us are clearly early birds. Others are night owls. And then, there’s a percentage of people that sit somewhere in between. And this isn’t a choice we make. This is the result of genetics and brains. Let’s take a look. 

Two chronotypes: early birds and night owls

You might think being an early bird or night owl is a personal preference or a choice, but that’s now how it works. Instead, a person’s chronotype determines if they’re an early bird or night owl. 

“Chronotype” is just a fancy way of saying “time type”. And you’re either an early bird, night owl, or somewhere in between. 

Early birds make up about 40 percent of the population, and they’re your typical “early riser” and “morning person.” These people thrive during the morning and afternoon, and their energy levels taper off into the evening, before they tuck into bed. 

Night owls make up about 30 percent of the population. They usually sleep in late and stay up late, and they thrive later in the day. But why can’t night owls just get up with the early birds. 

Turns out, it’s not that simple.

Why night owls are night owls

Being a morning or night chronotype isn’t a choice. Instead, everyone’s own unique circadian rhythm is influenced by important factors like genetics and brain structure and hormonal chemistry. Let’s take a look at both.

Genetics and night owls

Your DNA plays a big role in determining whether you’re an early riser or not. In fact, DNA hardwiring is one reason why certain people simply can’t get going bright and early the way morning people can. 

And if one or both of your parents was a night owl, there’s a good chance you’re one, too. 

Brain structure in night owls

In a small 2013 study from the University of Aachen, Germany, researchers found that the brains of early risers and night owls were different. To be specific, night owls had diminished integrity of the white matter in brain. This variance in white matter has been noted in individuals with depression and for cognitive function difficulty. 

That’s not to say that all night owls are depressed or struggle with normal cognitive function. But it does suggest that there are some differences between early birds and night owls that go beyond a mere choice to get up early or not.

While we’re talking about brain function, it’s worth mentioning that one reason why night owls struggle to function like early birds is because their prefrontal cortex stays in a sleep, drowsy state even when they wake up early. 

In case you’re wondering the prefrontal cortex is a brain region involved with planning, logical reasoning, emotional regulation and much more. So, it’s easy to see that night owls are at a strong disadvantage when they’re forced to wake up before their own circadian rhythm tells them to.

Why night owls can be more sleep deprived than early birds

In our society, night owls often get the short end of the stick. That’s because we mistakenly believe they can get up early, but simply choose not to. But that’s not the case. And when we operate under this belief, we actually increase the risk for night owls to be more sleep deprived than early birds. 

How to be a night owl in a world for early birds

Night owls have to live and work in a society which is primarily centered around early birds. Most work schedules favor early start and end times. What’s more, employees are expected to be productive and complete tasks from the morning to late afternoon.

But for night owls, this puts them at a strong disadvantage. Just when their prefrontal cortex is starting to rev up, it’s time to go home. 

It might seem like night owls sleep more than early birds simply because they sleep later. But we need to remember that they go to sleep much later, too. 

And when they have to keep up with the early bird schedules, they actually cut their sleep time short. But this is both unfair and unhealthy.

Not getting enough sleep on a regular basis is one of the surest ways to increase the risk for many serious health problems. 

So, if you’re a night owl, it’s important to be vigilant about seeking employment opportunities that respect your own unique sleep needs. What’s more, it’s important to make sure you get your Zzzz’s even if it’s at a time that’s discouraged or looked down upon.