Whether you are a morning lark or a night owl is likely to be down to your DNA, a study has suggested.
Researchers examined the DNA of nearly 90,000 people and identified genes which were linked to whether you were a morning or an evening person.
They found 15 locations in their DNA which were associated with whether they were early risers or not. And seven of these locations were found near genes known to be linked to circadian rhythm, which is also known as the body clock.
However the study, published in the journal Nature Communications, also found that preferences can change over time. The number of over-60s who liked mornings was more than double the number of people under the age of 30 who were natural early risers.
The research was carried out by 23andMe, a genetic testing company based in California.
Biology influences our behaviour
David Hinds, who was involved in the study, said: “We like to think of our preferences and behaviour as core to who we are and it’s interesting to see how our biology influences these things, like whether you are a morning person or a night owl. With large genetic databases available for study, we can uncover the genetics behind a variety of conditions and diseases and hopefully reach a better understanding of how we differ from one another.”
Scientists have known for a long time that a person’s genes can influence their natural circadian rhythm but more research is needed to understand why.
It is believed that the evolution may have played a part in some people being early risers while others stayed up late into the night. Those who functioned well in the mornings were likely to be the ones who went off to gather food while those who flourished at night would be likely to take up guarding duties.
Previous studies have found that being a night owl could well have consequences on your health. Those who stay up late are at a higher risk of developing diabetes than morning people even if they get exactly the same amount of sleep each night.
Night owls also had more body fat and their blood contained more unhealthy fats than morning larks.
Of course the idea that our genes can influence our health, preferences and behaviour is nothing new. DNA tests can reveal all sorts of things about a person from their heritage and paternity to their risk of developing a particular disease.