According to a recent study, new parents' marital status is the number one predictor of whether or not they will stay together. It doesn't matter how rich or well educated they are, cohabiting parents are at least twice as likely to split up as married parents of similar income or education. The author of this study, Harry Benson, found that of the 60 percent of families that remain intact until their children are 15, 97 percent are married. Read More.