Facebook has developed an algorithm that predicts whether your relationship will last or not. Researchers looked at 1.3 million Facebook users to determine their “dispersion”.
Dispersion is the extent of overlap in two people’s mutual friends. If you have high dispersion, you each have your own set of friends. Low dispersion means your friends are friends with one another.
High dispersion relationships are likely to last, but low dispersion relationships tended to be over in about two months. The conclusion is that you are more likely to have a strong relationship if you each maintain your own separate circle of friends.