There’s a simple explanation why you have a hard time getting out of bed in the morning, a new study has found.

The study, published in Nature Communications by gene startup 23andMe, has found that DNA is to blame. The reality is that some people are born to rise before their alarm clock, grab a cup of coffee and start chatting away, versus those who like to hang out until the wee hours of the morning and then drag themselves out of bed after hammering the snooze button over and over again, according to a Wired report.

23andMe is a company with a huge user-submitted genetic database, putting it in prime position to make interesting discoveries like this. The company is backed by Google and samples genes from bottles of saliva people willingly send them to make predictions on their medical futures, according to the report.

23andMe is an incredibly enviable company in that regard, as massive databases like theirs are what every major company craves, especially in the pharmaceutical industry.

Now, 23andMe is turning their vast database to public health purposes by starting with the survey question of whether or not someone was a morning person. Then they grouped together 90,000 individual DNA datasets, looked across the genomes, and found that 15 of the single nucleotide polymorphisms (SNPs) were present often enough to demonstrate a DNA link to morningness.

About seven of those SNPs had already been associated with sleep.