Some people have no trouble rising early and being productive, while others are most active during the evenings. This begs the question: are morning persons and night owls set apart by habit or biology? Habits certainly play a leading role, but all things being equal your genes might have a strong word to say in the matter.
Researchers at 23andMe, a genetics research company, studied the DNA of 89,000 people who self-reported whether they felt most active during the morning or evening/nights. Eventually, they spotted 15 distinct spots in the genome that were most likely to vary between the night owls and early risers. Not surprisingly, these are involved in regulating the circadian rhythm — the internal body clock that regulates wake/rest functions, like hormone production and brain activity. More about it in a previous ZME post about how body click mismatch could lend Martian settlers sleepless nights.
According to 23andMe, those who had gene variants most closely matching the “early rise” pattern were twice as likely to consider themselves morning persons. The findings were reported in Nature Communications.
“We think of our preferences as things that we come up with — things that are kind of spontaneous parts of who we are — but they do have a basis in biology,” says David Hinds, a statistical geneticist at 23andMe and a co-author of the study. “I think it’s just very interesting for people to see how their biology influences who they are.”
The Verge reports that previously similar studies were made on flies. Some 80 genes were identified which might influence a fly to be most active in the morning or, conversely, much later in the evening.
This isn’t the last word, though. The study is severely limited by the fact that it relied on an online survey to gather the self-reports. The geographic location, nor the season when the correspondents completed the survey weren’t taken into account, yet both are known to influence quality of sleep and how active people feel. What’s certain is that there’s considerable evidence at this point to suggest there’s indeed a genetic component that sets people apart in this respect. Don’t let this be an excuse for staying too late at night, though. Studies show that people who stay up at night are at a higher risk of muscle deterioration, diabetes, and metabolic disease.