Amanda at Pandagon writes well about changing norms, and how they may the the genesis for a lot of the current culture war hullabaloo:
It occured to me while we discussed this that this sort of thing probably goes a long way to explain why right wing blather about "traditional" families has really gained such a toehold in the public arena lately. For all the attention pain to the Baby Boomers who were into the counter-culture and whatnot, the vast majority of them really did make an effort to create the sort of family life they were raised to believe was standard--young marriage to a high school sweetheart, children, working hard, saving, enjoying some retirement time with the grandchildren. The dream didn't work out for a lot of people as planned, as the high divorce rate is evidence for, but they at least tried. But then they look at their kids who are really becoming full adults and a whole bunch of us clearly don't even care to try to achieve the dream.
For my part, I didn't grow up in any sort of traditional household, but I find the theory interesting. Worth reading and thinking about at any rate.
What I wonder about is this: it's not as though norms are simply disappearing. They may be factionalizing, national consensus on the wane, but the whole area of Family is too socially important for communities to not exert a norming influence. What's the new model, or what are the new values?