A new study by a Cornell University professor and a Facebook engineer analyzed 1.3 million users. The yardstick used to measure a relationship was something the researchers called dispersion, or how well a couple's mutual friends are connected.
Researchers found a couple with a "low dispersion" or when the couple's friends are well-connected on the site, are 50-percent more likely to end the relationship over the next two months than a couple who has a "high dispersion" or connections to different groups of people.
So, in simple terms: the study suggests people in the healthiest relationships have their own lives and friends. The findings will be presented at a conference on social computing in February.