And race, and wealth, and even political views:
> Mean number of offspring
> Wealthy liberal women (n = 35) 1.60
> Wealthy conservative women (n = 43) 2.49
> The difference is statistically significant. Wealthy white conservative women average 55 percent more kids than their liberal counterparts.
http://inductivist.blogspot.com/2012/03/fertility-among-weal...
http://www.feministe.us/blog/archives/2011/09/28/americas-fe...