Talk of “the gender gap” most often focuses on the fact that men in most countries earn more money and hold more powerful positions in politics and business than women. Yet there’s another gender gap developing in America, with men’s and women’s positioned reversed: As Michael Jindra has documented on this blog, men are significantly less likely than women to earn college degrees (or even high school diplomas), with negative consequences for their earning potential and job security in today’s unforgiving economy.

Attempts to address this problem—like apprenticeship programs, for instance—are often aimed at teenage boys and young adults. A new report from Third Way reveals that such an approach may be too little, too late.

As Thomas A. DiPrete and Claudia Buchmann document, boys fall behind girls academically as early as kindergarten, where (despite their slight advantage in math skills) boys are less apt to exhibit good social and behavioral skills, which directly affect academic performance. (Those skills “include attentiveness, task persistence, eagerness to learn, flexibility, organization, expressing feelings, ideas, and opinions in positive ways, and showing sensitivity to the feelings of others.”) The gender gap in skills widens throughout elementary school, and is actually larger than the persistent and better-known socioeconomic and racial gaps between kids.

Boys’ and girls’ performance in middle and high school continues along these lines. Close to half of eighth-grade girls, versus roughly one-third of boys, earn mostly A’s or half A’s and half B’s. And far from being irrelevant to later performance in school, eighth-grade grades “are a better predictor of completing college than are standardized test scores,” DiPrete and Buchmann show. Almost 70% of kids who earn mostly A’s as middle schoolers will complete college by age 25, versus just 30% of those who mostly get B’s and less than 10% of those who mostly get C’s. Boys continue to slip behind in high school. So it should come as no surprise that 57% of bachelor’s degrees each year now go to women.

How did such a wide achievement gap come to be? Here are DiPrete and Buchmann again:

The average male deficit in social and behavioral skills is certainly one factor, but there are other factors. As we show in our book, boys are more negatively affected than girls by growing up in families with absent or less-educated fathers. Boys are also more negatively affected than girls by classrooms that lack a strong learning-oriented environment. Too many adolescent boys underinvest in education due to out-of-date masculine stereotypes that depict academic excellence, attachment to school, and interest in art, music and drama as unmasculine. These stereotypes, in turn, are fueled by boys’ failure to understand (or the systems failure effectively to communicate) the strong connection between effort in school and later success in the labor market.

Whatever the causes of today’s gender gap in education, ensuring that struggling boys don’t fall through the cracks will redound to the benefit not only of those boys but also of their partners and the broader society.