If you’re nocturnal, you get it. You know you have to get up early tomorrow, so you wind down, turn off the screens and prepare for a responsibly early bedtime…only to get a second wind and stay up all night for no good reason. If you’ve ever wondered why you’re cursed to a life of late nights, horribly early mornings, and nonstop coffee, there’s a good reason—it all comes down to genetics.
The issue is common enough that it has a name: delayed sleep phase disorder, or DSPD. Researchers in Turkey set out to examine a possible cause for night owls.

The researchers were able to figure out what triggers this, and it has nothing to do with too much screen time or bad habits.

It all comes down to genetics—DNA, specifically.
Researchers found that people with DSPD tend to have issues with their circadian rhythm—the internal clock responsible for keeping your sleeping and waking periods on an even keel.

It turns out there’s a clear link between delayed sleep phase disorder and a specific gene, CRY1.

Mutations in the CRY1 gene mess up circadian rhythms, often resulting in a delay. This delay is what creates delayed sleep phase disorder.

In practical terms, this means that if you have a mutation in this gene, your internal clock will tell you to go to sleep much later than it would if you didn’t have the mutation.

Of the 70 people studied by researchers, 39 carried the CRY1 variant and 31 did not.

People with the gene mutation (let’s just call them ‘night people’) tended to feel sleepy later than people without the mutation.

This means that the midpoint for a good night’s sleep for night people falls between 6 and 8 in the morning, as opposed to 4 in the morning for non-night people.

Why does this happen? It all comes down to protein cycles in the body.

One protein, known as a cell activator, boosts activities in the cell. Throughout the day, this action also creates inhibitors, which eventually slow down activators until they stop. This is, in essence, how the body’s circadian clock works.

For people with the CRY1 gene mutation, inhibitors last longer, leading to circadian rhythms being stretched out.

“Carriers of the mutation have longer days than the planet gives them, so they are essentially playing catch-up for their entire lives,” said one of the study authors.

There’s good news, fortunately: the researchers say you can wean yourself off the night owl lifestyle.

You just have to enforce regular sleep cycles, making sure to wake up at the same time every morning.

h/t: Cell