Elisabeth Eaves at Forbes.com discusses a new study, commissioned by the American Psychological Association, on women’s careers in STEM (science, technology, engineering, mathematics) fields. The results are pretty much what you’d expect: Fewer women than men reach the highest levels in STEM fields because they have different priorities:

[W]rite the new report’s authors, “women’s preferences . . . constitute the most powerful explanatory factor.” That is, they’re just choosing to get out. Choosing to get out in such numbers that between 1993 and 2003, women earned 31.3% of chemistry Ph.D.s but were hired for only 21.5% of assistant professorships, with similar disparities in physics, engineering and mathematics. Further up the career ladder, the gender gap becomes greater; at the top 50 U.S. universities, the proportion of female full professorships in math-intensive fields ranges from 3% to 15%, the new study observes.

To be a top-ranked STEM researcher, you pretty much have to devote your whole life to your work. Fewer women than men are willing to do this, particularly once they start having children, and that’s the reason for the discrepancy.

Does it have to be that way? Eaves points out that other nations have more women STEM researchers than the U.S.:

One tally showed that 27% of French physics Ph.D.s were awarded to women versus 13% of U.S. physics Ph.D.s, with presumably no biological differences between French women and their American sisters.

Why the discrepancy? A feminist would no doubt say that Europeans have a better understanding of how to blend work and family life, and Americans should learn from their example. That’s one way to look at it — if your main goal is to get more women in scientific fields.

Another way to look at it is that (a) doing first-rate science, like many other jobs, really does require working long hours; (b) if people don’t feel like making that sacrifice, they should find a different line of work; and (c) if this requirement causes greater attrition among women than among men, so be it. That’s the American system, and the results show in U.S. dominance of every measure of scientific production, from citations to Nobel Prizes. If a budding researcher doesn’t want to face that choice, he or she can go to France, where scientists are civil servants and the nation’s research results show it.