When looking at the historical aspect of family values, "love", etc, I'd say you're incorrect. Culture doesn't reflect our instincts. Culture reflects the way a society deemed themselves fittest.
If your ancestors thought that finding 'the one" had the best impact on society as a whole (economically, etc), then that would be a heavy part of your culture right now.
Not all cultures their views are the same when it comes to divorce, etc, is an example of this. Our instincts don't point us towards the right solution because our instincts don't care. Biologically, it doesn't matter whether you divorce or not. However, it matters to your society and to your place in that society. Divorcing has implications that affect other people as well, like your children. That's why it matters, not because our body is telling us it matters. Same goes for finding "the one", how you find him, etc. Finding "the one" is something promoted so you're less likely to divorce, as divorce isn't deemed as something productive for society.
Did Britney want children because of her hormones? Maybe. Had society been constructed in such a way that Britney having children was possible for her to do on her own (considering her wealth and the time she was ready to spend on them), then maybe she would've gone that route. I think she just wanted children and it didn't matter to her how. Finding "the one", needing "the one" to be happy, straight up "the one", etc are all very much constructs of our society.