Philip Longman makes a somewhat novel argument in Foreign Policy this month. He notes that population growth rates in the industrialized world are slowing down, because families aren't having enough kids these days. Eventually populations will shrink in many countriesit's already happening in Japan. But Longman argues that, in most of these countries, what he calls "patriarchal" families will still reproduce faster than their godless liberal counterparts. So the world of the future will "disproportionately be descended from parents who rejected the social tendencies that once made childlessness and small families the norm." More kids will come from socially conservative families, basically.
Longman thinks that this explains why America is becoming more conservative; the right-wingers are having more babies. "Among states that voted for President George W. Bush in 2004, fertility rates are 12 percent higher than in states that voted for Sen. John Kerry." Well, maybe. But probably not. Even granted that conservatives tend to have more kids than liberals, that doesn't mean that the kids all stay conservative. Polls in the United States show that every generation tends to be more liberal than their parents, at least on social issues. George W. Bush may be president, but the country as a whole is far more socially liberal than it was, say, thirty or twenty years ago. (Really.) So it's not clear that demographics are necessarily going to lead to "religious revivals and a rebirth of the patriarchal family [rebirth? did it ever die?]" all around the industrialized world. But Longman's argument's worth reading all the same.