You don't need to read your DNA to figure out that you're a morning person. You rise before your alarm clock. You practically levitate out of bed. And coffee isn't so much the best part of waking up as it is an excuse to chit chat with all those other wonderful human beings. You don't need your DNA to tell you that you love mornings...but the evidence might be written there anyway.

At least, part of it. A new study published in the open-access journal Nature Communications says that at least some of your wake-up preference is encoded in your genes. Now, it's not like anybody needs a diagnostic test for morningness. (Unless you want one. Would you buy one?) No, this study is notable because of who did it: the gene startup 23andMe, using a subset of their vast, user-submitted genetic database.

You remember 23andMe, right? Backed by Google money1, set up to sample the genes people sent them in bottles of saliva and tell them what kind of medical future they might expect? Planned to partner up with big pharmaceutical companies to use all that data to develop new therapies? Got into a big fight with the FDA about whether they were doing diagnostics or not? Right, that 23andMe.

Well, this is one of nearly 50 publications of results from all that spit. And it's the punchline to a Garfield comic.

It started with a simple survey question: Are you a morning person? Simple, but not perfect. 23andMe's scientists had to do a bit of pruning before they were comfortable with their dataset. For instance, some people were neutral (Seriously? Who is neutral about mornings?!), and others confused as to whether they liked morning or evenings better. Once they got rid of those sadly confused people, they got rid of anyone without European ancestry. This wasn't eugenics. They were trying to standardize the dataset. "We do this mainly because it simplifies the statistical analysis necessary to deal with the group," says David Hinds, principal scientist at 23andMe and coauthor of the study. Anomalous gene markers are more likely to jump out when you're comparing DNA that is mostly the same. Hey, actually, that does sound kind of eugenic. But anyway.

And compare they did. Even after all that pruning, the researchers still had nearly 90,000 individual DNA datasets. They peered across those genomes, looking for single nucleotide polymorphisms, or SNPs—single base-pair mutations that modern sequencing technology is pretty good at picking up. In people who had answered "yes" to the question of morningness, 15 of these SNPs showed up often enough to cross a critical statistical threshhold. That's right: These people's sunny dispositions are not merely annoying, but also possibly hardwired.

Of those fifteen, other studies had already associated seven with sleep—mutations like a neuropeptide linked to prolonged REM sleep in rabbits, and another linked to light sensitivity and circadian rhythms.

So, hey, sure, could be. Why not? Well...for sure, "do you consider yourself a morning person," isn't the most robust methodology for nailing down who is what kind of waker. "What that means is some people who were morning people are actually biologically night people," says Barbara Stranger, a population geneticist at the University of Chicago.

But 23andMe's dataset is so huge those errors probably don't matter. Even if the some people miscategorized themselves, the big data signal most likely swamped the noise. "When we talk about this statistically, we ask if it creates false positives," says Stranger. "The answer is no."

Which is good, but doesn't answer an even more pressing concern, which is: Come on. Who asked for this? This is what the vaunted 23andMe comes up with? We gave them our spit.

Geneticists kind of buy it, actually. "The genetic regions they discover here give us a window into the biology of sleep," says Daniel MacArthur, a population geneticist at Massachusetts General Hospital. 23andMe really does think it'll get new pharmaceuticals out of this. Last year, the company made a deal with Reset Pharmaceuticals to develop drugs targeting the body's circadian rhythms.

Some of these targets could be for the morningness trait itself. Morning people are less likely to be depressed, obese, and they sleep more soundly. They are terrible in every way, basically.

In fact, sleep meds have been part of 23andMe's plan all along. Or rather, part of its plan since 2013, when the FDA told the company that it couldn't go around warning people about disease markers in their DNA based on saliva-based mail-order SNP tests. The agency suspected that could lead to people getting more specific tests that they didn't actually need.

So 23andMe pivoted, as they say, to non-medical advice and gathering data for studies like this one, planning to sell it to drug companies for development. "23andMe sends out surveys, and nobody has to fill them out," says Steven McCarroll, a geneticist at Harvard's Broad Institute. "These people are co-owners of a research discovery."

But not, you know "co-owners" in a financial sense. Your data might yet lead to a drug to make people bright-eyed and bushy-tailed, but you won't see a cut. And they wonder why some people don't want to get out of bed in the morning.

1UPDATE 2/2/16 12:30 EST: This story has been updated to correct the source of 23andMe's funding; it has not received money from Facebook.