So says a new research paper written by Jon Kleinberg, a computer scientist at Cornell University, and Lars Backstrom, a senior engineer at Facebook. Their key finding was that the total number of mutual friends two people share — embeddedness, in social networking terms — is actually a fairly weak indicator of romantic relationships. Using dispersion, Backstrom and Kleinberg doubled their accuracy: 50 percent of the time, a person was romantic partners with the person who was the most dispersed across his or her social network. In other words, your significant other won't just share many friends with you, but friends from all walks of life: your colleagues, your high school buds, your college friends, your family, and so on. Their dispersion algorithm was able to correctly identify a user’s spouse 60 percent of the time, or better than a 1-in-2 chance. For married people, their accuracy rose to 60 percent, a figure which they say is more than 30 times higher than random guessing would produce (everyone in their sample had at least 50 friends). The researchers were able to work with their findings to produce a telling observation about the health of a given relationship: The more dispersion a relationship demonstrated, the more likely it was that that relationship would still be around 60 days later (the researchers excluded married couples from this analysis, though that would be quite interesting to see too).
– Facebook data scientists can figure out who you're sleeping with, even if your relationship isn't "Facebook official," and in a new paper researchers explain how they figured out the method, the Atlantic reports. Turns out the key is to look at more than just mutual friends. "Embeddedness," or the number of mutual friends two people have, can show how close those people are (the more mutual friends, the closer they are). But researchers found embeddedness predicted the correct significant others just 24.7% of the time. A more accurate predictor is something called "dispersion." That means researchers looked at how many networks were shared between two people, working on the theory that your romantic partner will have met your family and your current friends and co-workers, as well as old friends from high school or college. By looking at which friend was the most dispersed across all of a Facebook user's networks, researchers upped their accuracy at predicting significant others to 50%. "A spouse or romantic partner is a bridge between a person’s different social worlds," one researcher explains, according to the New York Times. Oh, and dispersion also works to predict the health of your relationship: The more dispersion a user had with his or her partner, the more likely the relationship was to last at least 60 days.