There are fewer women at the top because they have a different work/life balance than men, it is claimed. Mothers’ careers progress slowly because they are mothers — because they have to spend more time on their children.

There’s some appeal in this explanation; it seems intuitively correct. Mothers have greater childcare responsibilities than fathers. And while we may hope for a different division of labor some day, we speculate that these work/life realities explain why women who are mothers are on slower career tracks than men.

It’s the realities of daily life behind the statistics that in fact explain the statistics. Correlation becomes causation. But that’s a mistake in how we think. There’s more to the story.

New evidence on womens’ careers is presented in the White Paper on the Position of Women in Science in Spain. A man with children, the report concludes, is four times more likely to become a full professor than is a woman with children.

When comparing men and women with the same personal and professional characteristics, the same academic productivity, and both with children, we see that having children affects women much more negatively: a man with children is 4 times more likely to be promoted to Full Professor than a woman with children.

But instead of invoking the intuitive explanation mentioned above, the white paper emphasizes that women who have children are discriminated against simply because they are mothers and not because their job performance is actually different.

Researchers from Cornell University published evidence of this. The article Getting a job: Is there a Motherhood Penalty, by Shelley J. Correll, Stephen Benard, and In Paik, appears in the American Journal of Sociology (2007).

Participants in their study rated fictitious job applicants by reading constructed files. Some resumés they read included Parent-Teacher Association coordinator as an activity, while others had Fundraiser for neighbor association. This had been shown by another researcher to successfully convey whether someone is a parent or not.

The applicants were rated on competency and commitment, and the results are clear.

Mothers were judged as significantly less competent and committed than women without children… Mothers were also held to harsher performance and punctuality standards. Mothers were allowed significantly fewer times of being late to work, and they needed a significantly higher score on the management exam than non-mothers before being considered hirable.

As if this weren’t enough, when they did hire mothers, the subject participants gave them a 7% lower starting salary than the non-mothers, and considered them less well-suited for future promotion. All this was determined on the basis of a paper file!

Part of the story, both in the Spanish study and in Correll et al.’s article, is about men; I blog about that separately in The fatherhood bonus: Have a child and advance your career.

The conclusion about women is that having children does indeed correlate with one’s career path. Mothers are less likely to be promoted than men, and they are also less likely to be promoted than non-mothers.

But this happens for irrational reasons; children do not cause this difference. The explanation is not simply that mothers work less because they have more to do at home. An important part of the explanation is that the very fact of being a mother is perceived as a disqualification.

Leadership in organizations must acknowledge implicit discrimination and must take specific steps to counter it. There are many possible strategies; targets are just one.

I remember a professor from graduate school speaking once about another graduate student who was expecting a child. He commented on her career simply by saying, “She’s made her choice.”

But maybe she hadn’t; maybe we’d made it for her.

Related entry: There are only three reasons women don’t make it to the top