Religious Americans have more children than secular Americans. (Of course, I must ask, what’s cause, and what’s effect? Young, single Americans tend to be more secular than their older, married parents.) From Political Victory: From Here to Maternity:
Over the past decade, fertility rates among all major American ethnic groups have either remained low or fallen dramatically. Between 1990 and 2002 fertility declined 14 percent among Mexican Americans and 24 percent among Puerto Ricans. African Americans, according to the National Center for Health Statistics, now have a lower average fertility rate than whites, and they are no longer producing enough children to replace their population. But one big difference in fertility rates remains: Conservative, religiously minded Americans are putting far more of their genes into the future than their liberal, secular counterparts.In Utah, for example, where 69 percent of all residents are registered members of the Church of Jesus Christ of Latter-day Saints, fertility rates are the highest in the nation. Utah annually produces 90 children for every 1,000 women of child-bearing age. By comparison, Vermont — the only state to send a socialist to Congress and the first to embrace gay unions — produces only 49.
Fertility correlates strongly with religious conviction. In the United States, fully 47 percent of people who attend church weekly say that their ideal family size is three or more children. By contrast, only 27 percent of those who seldom attend church want that many kids.
I’d like to see the numbers for Mormons, Catholics, “evangelical” (“born again”) Protestants, and “mainstream” Protestants broken out.