I think "Family values" are more about moral absolutism than actual families so it's not necessarily as related as it may seem. I'd be pretty unsurprised by a correlation here but I'd be quite surprised if "Family values" were actually found to be a causal factor in the breakdown of marriages. I would suggest that the morals issue is just a symptom of something else, which can be a contributing factor in the breakdown of marriages, but I have nothing to back that up. (I'm tempted to say that something else is stupidity, but I'll refrain... Sort of)