Why Waking Up Early Is So Hard
Call it the "clock gene." That's the long and short of it. Literally. Whether you find it impossibly difficult to get up early in the morning or you just can't keep your eyes open after 9 p.m. is because of a gene called Period 3, which has been identified by researchers at Britain's University of Surrey. Period 3, which helps to regulate our internal body clocks, comes in two sizes. A long one. And a short one. People who have an extreme preference for early mornings are more likely to have a long version of Period 3, while those who stay up until the wee hours of the morning are more likely to have the shorter version, reports the BBC News.
Of course, that's the simplistic explanation. Study leader Dr. Simon Archer is the first to admit that your preference for sleeping late or retiring early is a complex behavioral trait that is governed by more than a single gene. "It is a combination of genes that interact together to form your body clock," he explained to the BBC. "But, of course, there is an influence from your lifestyle. It is not all to do with your genetics. You can chose to follow a particular life pattern. You can override your genes."
The study: The University of Surrey researchers corralled some 500 people who visited London's Science Museum. In addition to taking DNA samples from their cheeks, the researchers asked them to complete questionnaires about their lifestyles to determine if they were larks or night owls. They did this by asking what time of day they preferred to exercise and how difficult they found it to wake up in the morning. Then they compared the DNA results--the length of that Period 3 clock gene--to the questionnaire answers.
The results: "We found most of the extreme morning preference people have the longer gene and the extreme evening preference people have the short gene," Archer told the BBC. "There are extreme morning people and extreme evening people, and it seems that behavior has a genetic basis to it." The study findings were published in Sleep, the journal of the American Academy of Sleep Medicine and the Sleep Research Society.