Wow my first official post here even though I've been reading for years and even have some contributions in the archive!
Anyway, I just found this thread and have to comment. While the person who said this was making a huge, rude generalization, there is the tiniest tidbit of truth to it. I was in an incredibly abusive marriage and one reason I stayed was I had no money to get out. (One of my abuser's behaviors was to throw a fit and refuse to let me work or drive.) I personally don't correlate class with money, but there is some truth to the idea that poor women in particular might stay married because they feel they cannot support themselves alone. I know several low or no income women who are in miserable marriages but stay because they can't afford to leave. It is just one of the reasons a woman will stay in an abusive marriage. I also know a few men who refuse to get divorced because they fear they will lose everything they own. So I guess if you define "low class" as "low income," you could come to a roundabout conclusion that that lower class people are more likely to stay married.
On the other hand, recent studies show that higher education leads to later, but longer lasting marriages as well.