If you've ever tried renting an apartment with companions, you probably know this feeling. This is when closer to the night your neighbor decides it's time to hang out and listen to your favorite Iron Maiden album. Or maybe you had to grit your teeth from a headache when some freak stomps loudly at dawn, rattles dishes in the kitchen and turns on the coffee grinder when all decent people are sleeping.
It turns out there is a very good reason why these people hate each other. The thing is that the biological clock is rigidly built into our genes.
In the world of sleep research, there are "night owls" - people who go to bed after 11 pm and get up after 8 am, and "larks" - mythological creatures who get up before 8:00 even on weekends. There are many studies on how these two different sleep patterns relate to different types of brains, but almost nothing is known about what makes this difference. However, according to a study published in the journal Nature in 2016, the difference in daily biorhythms can be recorded in our genes.
The study was carried out using a genome-wide association study, also known as GWAS, using the DNA of nearly 90,000 people who submitted their genetic material to 23andMe, a private biological company in California. The researchers found 15 genetic patterns that were thought to be related to the habits of the early risers. Some of these patterns relate to the mechanisms that we know determine the diurnal biorhythm, while others are associated with genes that are responsible for the eye's response to light. The takeaway is pretty clear: If you tend to wake up early, it is most likely due to the demands of your genes.
However, it is important to remember that a person's daily biorhythm rarely remains constant throughout life. In addition to genes, there are many other factors that determine when we want to sleep and how many hours of rest are needed to recuperate. In general terms, men are more likely to be "owls", while women are more likely to be "larks", and in addition, age plays a rather significant role in the daily biorhythm. If younger schoolchildren are more often "larks", then teenagers are famous "owls". Many adults move back to early risers as they get older, while others remain late sleepers into old age. In fact, there may be some evolutionary reason why sleep patterns are shifting towards early risers as we age.
There is still no consensus on what is better, to be an "owl" or "a lark". However, some scientists have a version that "owls" are smarter, but more prone to depression, and larks are happier people, but not necessarily healthier. However, be that as it may, probably at different moments of life, most of us become both.