In the absence of data one random-ass hypothesis is as good as another. Here is a different one: Thanks to the invention of reliable birth control, the declinin

In the absence of data one random-ass hypothesis is as good as another. Here is a different one: Thanks to the invention of reliable birth control, the declining risk of childbirth (particularly late-in-life childbirth), and the decreasing economic value of children in modern urban societies, human mating rituals in such societies have tended to become orders of magnitude more baroque and complex, now typically extending over decades and involving multiple pairings-off, moving in and out with each other, extended auditions with both sets of families, and careful correlation of childbearing attempts with career paths and financial flows. Remember, though: This is a hypothesis, no data. Consult your friendly neighborhood sociologist, who will tell you that the world is more complicated than that. Consider, for example, that not everyone in America is in the same social class...