An Effect of the “Contraception Revolution”
An article on Alternet is looking forward to perfect contraception, apparently because it will supposedly make pro-natal religions obsolete. I suspect the contrary will happen. It will merely cause pro-natal people (who tend to be religious) to outbreed the rest.
An effect of slightly-imperfect contraception
While reading the above-mentioned article, I realized that slightly-imperfect contraception has produced lower birth rates among people who are both irreligious and smart. In other words, it is promoting religious smart people and atheists who are ot-nay oo-tay ight-bray. That might explain the New American Divide.