As early as eighth grade, girls are more likely to say they want to go to college and to earn better grades in school because of it, a new study says.
The National Bureau of Economic Research working paper  set out to account for a relatively recently widened gender gap in secondary school grade point averages. Looking at 8th- and 10th-graders and high school seniors, the researchers searched for correlations between G.P.A. and plans for the future, non-cognitive skills (social skills, motivation, etc.), the family environment, and working while in school.
One significant relationship emerged.
“There has been an important change in the vocational aspiration of girls that can explain a large part of the gender differences in their academic achievement,” said Nicole M. Fortin, a co-author of the study and professor at the University of British Columbia’s Vancouver School of Economics.
Those career goals translate into plans to attend college, which in turn prompt girls to do better in school than boys, the paper argues.
Although the gender gap in G.P.A. level for high school seniors has hovered around two tenths of a grade point (for example, 3.1 vs. 3.3 in 2009) for three decades, that has not historically translated into higher educational attainment or better labor market outcomes for women.
More recently, more high school seniors of both genders are earning As (presumably due to less grading on a curve, the authors posit), but girls are earning top grades even more often; from the 1980s to the 2000s, the difference between the proportion of girls and boys earning As nearly doubled, from 3.2 to 5.4 percentage points.
At the same time, the proportion of girls expecting to work a job requiring a postgraduate degree rose from 15.3 percent in the 1980s to 27.1 percent in the 2000s; for boys, it rose only from 13.5 to 16.4 percent. The authors argue it’s not a coincidence that during the same period, the percentage of girls expecting to work in a clerical job at age 30 fell from 21 to 3 percent -- but that drop was not mirrored among boys expecting to work in skilled or semi-skilled jobs such as craftsmanship or protective services.
“There was a particularly sharp increase at the beginning of the 1990s where about a quarter of girls wanted to be in an occupation that might require a graduate degree,” Fortin said. “The girls are responding in a way to changes in the labor market that are actual and real.”
As early as eighth grade, a gap emerges among students who say they “will definitively go to a four-year college,” with women accounting for 55 percent of the gender ratio. Today, women outpace men in college enrollment by a ratio of 1.4 to 1 ; in 2010, 36 percent of women who are 25 years old had graduated from college,  compared to 27 percent of men.
The paper’s data come from the National Institutes of Health’s Monitoring the Future survey, which the study authors note contains self-reported information. However, boys tend to overstate their grades, so if anything the G.P.A. gap is likely wider, they say.
But Claudia Buchmann, a sociology professor at Ohio State University and co-author of The Rise of Women , cautioned against relying too much on data students self-reported in a survey designed to measure substance use.
She acknowledged it wouldn’t be surprising if the G.P.A. gap is growing, but questioned whether career aspirations are the main cause of that.
“Grades have just as much of an influence on aspirations as vice versa,” Buchmann said, referring to her book’s findings that girls are more engaged and motivated at school, in part because of the intrinsic gratification that good grades bring. (Peer culture, parental guidance and non-cognitive skills also play a role.) “That is part of how academic aspirations are formed – they’re like, ‘Wow, I like this, I’m good at it, my teachers care about me and therefore I want to keep doing this. I want to go to college’.”
The bigger question, Buchmann said, is why boys aren’t getting the message that they do need to do well in high school to succeed in college, that they won’t just magically land some high-paying job when they graduate 12th grade.
“It’s not just about career plans, it’s not just about, ‘Oh, I can be an electrician,' ” she said. “The study reinforces a lot of the things we already know and doesn’t really dig too deeply beyond those key relationships that aren’t really understood.”
If there is one message for teachers to get out of the study, it’s how to get boys more engaged in school, Fortin said. An overconfidence among boys in their ability to get by without doing well in school is a concern. But she also worries about the girls.
“The percentage of girls who aspire to get a graduate education is much higher than what we will see in reality,” she said. “I’m concerned that they will have to lower their expectations. They might find it a lot tougher in reality.”