Joy Pullmann of the Federalist highlights a new report that documents a disturbing demographic trend.

The world’s richest countries typically have the world’s lowest birth rates. The highest-income people in those wealthy countries on average have the smallest family sizes.

Those two facts conflict with the broad perception, especially among lawmakers, that Americans aren’t having babies because they’re worried about how expensive kids are. So may the results of a new study out today, which finds that the more career-oriented individuals and wealthy societies become, the more their fertility declines.

“Highly work-focused values and social attitudes among both men and women are strongly associated with lower birth rates in wealthy countries,” authors Laurie DeRose and Lyman Stone write in the Institute for Family Studies paper. Later, they observe, “placing a high degree of value on work can dampen fertility desires and make them less likely to be realized.”

This all suggests, the authors say, that specific societal and individual values strongly influence birth rates in wealthy countries, not necessarily income or welfare availability.

Many demographers have argued that societal values that flatten the differences between the sexes would help boost fertility — for example, if husbands did more childcare and household chores and women had more earning power. Yet this study finds that people with so-called “egalitarian” values are less fertile than those who embrace differences between men and women.

The differences were especially pronounced among those who both expressed feminist values and prioritized work over family. Beliefs about sex roles affected fertility the least among those for whom family was their highest priority.

“Men and women who place a high value on work and expect a high degree of gender equality have the lowest fertility, whereas gender equality expectations are less predictive of fertility among men and women who see work as a less important element of life,” the authors find.