No great surprise: Facebook knows who you’re dating:

Though 27% of Facebook users don’t list their relationship status at all, only about half of those people are single, according to a Men’s Health article. If you’re one of these users committing the crime of omission, Facebook’s team of “in-house sociologists” has been researching ways to find you out. […]

f you’re “friends” with several of your other half’s co-workers, family members and friends, for example, Facebook may deduce that your only mutual link to these profiles is your assumed wife/husband/girlfriend/boyfriend. Researchers said they had a high success rate in correctly guessing someone’s romantic partner by this method.

Of course, these types of sleuthy Facebook social science projects have been ongoing for some time now. A research project earlier this year from Cambridge claimed it had success detecting non-volunteered information like users’ sexual orientation, ethnicity, religious and political views just from what people “liked” on the site.

This opens up a potentially crucial role for Facebook in the human social domain. You know what I always hated about relationships? I hated trying to nail down where exactly things stood. I’ll bet there is a lot of potential here for Facebook to tell you. Or they can at least give you a heads up. “In case you were unaware, statistically speaking, you are in a relationship with Suzie.” It would be a very helpful pointer for the unaware.

Of course, you could decide that you don’t want to be in a relationship with Suzie at all. And you can say “Facebook! You’re wrong!” But you ought to make sure that Suzie thinks that Facebook is wrong, too. It could have a real positive social impact of making us have the very important conversation that some are too good at avoiding. Among other things, that’s one of the things I consider great about the institution of marriage. It seems to break up more relationships than it saves, sometimes. But! It helps those who were going to break up later realize that they need to break up sooner.

On the other hand, Facebook can’t figure out which movies I want to see. So maybe it would be in over its head here.

On a more serious note, it rather blows my mind that they haven’t gone hog wild of matchmaking. I met Evangeline (as well as Porky, the girl who was way out of my league) on something that was actually somewhat like Facebook, though only a little. It wasn’t a full-on social networking site, but it wasn’t a matchmaking site either. Since it wasn’t the latter, it made trading messages a lot less formal and more friendly than on the matching sites I was on at the time. The creators of that site are probably kicking themselves for falling just shy of what Facebook became. Now it doesn’t even have a Wikipedia entry and the domain points to Teen.com.