I was reading here that people who marry after living together are more likely to get divorce than those who live separately before they marry.  The author quotes Michael McManus, coauthor of Living Together: Myths, Risks & Answers.  The author says that only 45 percent of people who live together get married, and those people are 50% more likely to divorce.

I wonder why that is?  Do they get married because they feel pressure from family, friends and society to make it legal and then feel trapped once they do say those vows? 

People who say they live together because it's easier to split up if you aren't married may already have an unconsious strike against them.  They are already living under the assumption the relationship won't work.  Then when they add the legal ties of marriage to the relationship, those afraid of the commitment in the first place might feel like they are in over their heads. 

I would think that having lived together, they would know each other on a deeper level, and be more certain their relationship would last.  Maybe people really do change once the wedding ring is on the finger.