In contemporary America, as Syracuse University Professor Arthur Brooks points out in The Wall Street Journal, that cluster of values increasingly gets denominated "conservative." Analyzing the 2004 General Social Survey, Brooks reports that self-identified liberals have 1.47 children, on average, compared to 2.08 children for self-identified conservatives, a "fertility gap" of 41 percent which (he says) is widening at a half percentage point a year. Even after controlling for age, income, education and religion, he says "the liberal will still be 19 percentage points more likely to be childless than the conservative."
But beyond liberal or conservative, America is a special case. Between 1980 and 2000, while Europe, South Korea and Japan's birth rates plunged, the U.S.'s fertility climbed from 1.85 back up to 2.06. Immigrants, who bring their "less developed" family values to our shores, are a part of the explanation. But American college-educated white women (to name one of the least fertile groups) have birthrates that would be the envy of Europe.
Something is different about America. Consider this both a reassurance and a warning: The future belongs to the people and peoples who dare to give themselves to love.