Would you describe yourself as a morning person? Or are you more a chronic night owl, functionally at your best after the sun goes down? Turns out it might be about more than just your habits: a new study published in Nature reveals that "morning people" actually have certain unique genetic traits. Fifteen of them, to be precise. So if you're a night owl who has been skeptical of the idea of "morning people" and whether they actually exist (or if they're just a myth invented by health magazines), it turns out that not only are they real, but that that tendency towards early rising is encoded in the building blocks of their beings. And that has some interesting implications for whether night owls can ever truly convert to a more morning-oriented schedule, or whether some people just have a genetic advantage.
People use the terms "circadian rhythms" and "body clocks" or "biological clocks" interchangeably, but they're not actually the same thing. Our biological clock in our nervous system drives our circadian rhythms, which determine when we feel awake and when we feel sleepy. They're also liable to be affected by external stuff, though: it's well-known that things like exercise and light can interfere with rhythms, particularly when it comes to the production of melatonin, which plays a huge role in determining our sleep cycle. So what does being a "genetic morning person" actually mean for this complicated process, and does waking up at 6 a.m. naturally without grumbling give you any advantages? (Besides bragging rights, of course.)
What Your DNA May Say About Your Circadian Rhythms
We've known about the impact of genetics on circadian rhythms for a while. A 2015 study from the University of Leicester looked at the genes of fruit flies, and saw a huge difference between the genetics of the ones more active in the morning compared to those who came to life in the evening. Genes aren't just inert frames, though; they do something called gene expression, which influences huge swathes of human functioning. And the Leicester scientists found that, weirdly, the genes that seemed to mark out the difference between night and morning flies often didn't seem to relate closely to circadian rhythms at all; they were concerned with other things. So there's more to our body clocks that just our rhythms.
But that's fruit flies. What about humans? Well, this new study certainly surveyed enough of them: nearly 89,000, in fact. It's one of the first studies to actually look at the human genome and see how it lines up with "morning people" and "night owls", and the results were pretty startling.
Interestingly, the scientists utilized the gene sequencing business 23andme, which produces genetic profiles (and figures out what your genes say about your health and ancestry) for a flat fee. Tens of thousands of 23andme users were asked if they identified as "morning people", and then their genetic sequences were examined. (Interestingly, only 39.7 percent of men said they did, compared to 48.4 percent of women. Seems it may be a more female trait.) And it turns out that fifteen separate genetic indicators, only seven of which are thought of as "circadian genes," may indicate a morning person.
The ones that aren't circadian pose a bit of a puzzle. Even the scientists said that the relationship these specific genes have to being a morning person is "less clear". One is associated with restless leg syndrome, and another has a relationship with cardiac rhythms. But even the more definitively sleep-regulating ones are complicated: they relate to things as diverse as night blindness, dopamine regulation and the workings of the visual systems in our brains. Basically, the genetic blend that makes up a morning person is a pretty complicated recipe.
The Body Of The Morning Person
While the scientists were checking out the gene sequences, they looked at a few other traits too. Turns out that being a "morning person" in their 89,000-strong cohort was associated with a lower risk of depression; self-described early birds were also less likely to be either underweight or obese. It points to an interesting truth: your genetic predisposition to being a "morning person" may be seriously influencing your behavior, mood and life in general.
We already knew that the bodies of night owls and morning people are often very different. A 2013 study found that the structures of night owls' brains tend to have less white matter (which is the insulation the brain uses to transmit nerve signals) than morning people. But it's not clear whether that was cause or effect. Did the white matter not grow in the first place because the person was genetically night-owlish? Or was the growth somehow slowed by years of late nights? We may now be getting closer to an answer.
The problem with this genetic discovery? It might mean that changing your circadian rhythms is a harder proposition than we had thought. We're not yet at the point where people can get their genetics fiddled with to make mornings easier, but that may be the next big step. Got a big promotion coming up? Have your genome altered to let you work nights with ease! OK, I'm fantasizing. But for the time being, non-morning people can use this information as an excuse for their repeated hitting of the snooze button; they're just not genetically built for 6 a.m.