This month's New Yorker has an article on the relatively high rate pregnancy amongst the teens of evangelicals.
Thanks for the pointer to Tyler Cowen who asks us to consider two points:
The first question is whether they do, adjusting for all the proper demographics. Second, I wonder if there isn't also a combined lifecycle/genetic effect. Maybe if you're rowdy when you're young, you're religious when you're old, but the kids that pop out are on average rowdy too.Cowen highlights this quote:
Bearman and Brückner have also identified a peculiar dilemma: in some schools, if too many teens pledge, the effort basically collapses. Pledgers apparently gather strength from the sense that they are an embattled minority; once their numbers exceed thirty per cent, and proclaimed chastity becomes the norm, that special identity is lost.My emphasis.