The much-discussed gender gap in science, technology, engineering, and mathematics (STEM) can be explained in part by differences in individual students' comparative academic strengths, a gap which only grows as societies become more gender egalitarian, a recently released study shows.
The gender gap in STEM is a persistent quandary for policy makers. Recent data from the Economic and Statistics Administration found that women made up more than half of college-educated workers but only 25 percent of college-educated STEM workers, and that while nearly as many women hold undergraduate degrees as men, women make up only 30 percent of STEM degree holders and are a disproportionately low share of degree holders across all STEM fields.
"Despite considerable efforts toward understanding and changing this pattern, the sex difference in STEM engagement has remained stable for decades," the study's authors write. "The stability of these differences and the failure of current approaches to change them calls for a new perspective on the issue."
The study looks at surveys of 475,000 adolescents between ages 15 and 16, across 67 nations or economic regions, collected by the Programme for International Student Assessment (PISA), which is administered by the Organization for Economic Cooperation and Development (OECD). The PISA conducts surveys on international students' literacy in, interest in, and enjoyment of science, reading, and mathematics.
The study's authors used these numbers to measure students' "intraindividual strengths," that is, how strong a given student is in one subject area as compared against the other two subject areas. The authors produced standardized students' scores in the three subject areas for each nation, then compared those scores against the student's average, and re-standardized the results across the nation.
The result shows how much stronger a student is in a given subject area compared to other subject areas and then compared to other students in his or her nation. Therefore, even if a student underperformed the national average in all three areas, his or her intraindividual strength in, say, math, could still be greater than the intraindividual strength of the average student. One could be bad at math, but still much better at math than one is at reading and science when compared to one's national peers.
The study's authors applied this approach to the PISA data set, focused specifically on science skills. They found that, in general, difference in actual science skills washed out: in 19 countries, girls outperformed boys; in 22 countries, boys outperformed girls; in the remaining countries, there was no statistically significant difference.
However, in all countries except for Lebanon and Romania, boy's intraindividual strength in science was greater than girls'. In other words: while girls and boys were equally good at science, science was a greater individual strength for boys than for girls when it was compared to other subject areas. The study further notes than girls' intraindividual strength in reading was greater across all countries, while boys' intraindividual strength in math was greater across all countries in the dataset.
"We found that on average (across nations), 24 percent of girls had science as their strength, 25 percent of girls had mathematics as their strength, and 51 percent had reading. The corresponding values for boys were 38 percent science, 42 percent mathematics, and 20 percent reading," the authors explain.
"Thus, even when girls outperformed boys in science, as was the case in Finland, girls generally performed even better in reading, which means that their individual strength was, unlike boys' strength, reading," they add.
These patterns of differences also persisted for analogous measures of intraindividual self-assessment of skill (i.e., how good a boy or girl thinks he or she is at a given area, as compared to the other areas) and intraindividual joy (i.e., how much a boy or girl enjoys one area as compared to other areas).
The authors say that this helps explain the persistence of gender gaps in STEM fields, the place where such gaps appear to persist, even as they vanish in others. While girls are in general just as skilled in the sciences as boys, boys have higher average intraindividual strengths in math and science, leading to self-specialization at the college level based on intraindividual strength.
"When boys are relatively better in science and mathematics while girls are relatively better at reading than other academic areas, there is the potential for substantial sex differences to emerge in STEM-related educational pathways," the authors write. "The differences emerge from a seemingly rational choice to pursue academic paths that are a personal strength, which also seems to be common academic advice to students, at least in the United Kingdom."
But the "most important and novel finding" is not only that the intraindividual strength differences persist across nations, but that the difference between girls' and boys' intraindividual strength in science and reading increased as countries became more gender egalitarian. Finland, for example, ranks very highly in gender equality, yet has a pronounced gender gap in its STEM degree graduation rate. The overall trend, comparing across nations, mirrors this counterintuitive fact: as equality increases, so too does the STEM graduation gender gap and the gap in intraindividual strength.
To explain this puzzling pattern, the study's authors note that nations with greater gender equality appear to be more developed in other ways, a fact they capture using measures of overall life satisfaction. This fact, they argue, means that in less egalitarian nations, girls may spend less time focusing on their academic strength, opting for STEM fields that are a more surefire way to life satisfaction.
By contrast, living in a more developed—and also more egalitarian—nation may give men and women the luxury of specializing in what they are intraindividually most excited about and good at, with the downsides of opting out of STEM being lessened by a stronger welfare state or wealthier society overall.
"Economic and general life risks are lower in gender-equal countries, which in turn results in greater opportunity for individual interests and academic strengths to influence investment in one academic path or another," the authors write.
The study's authors do not make strong claims about how to act on their information. But they do note that, if they are correct, STEM gender parity may prove to be more substantively challenging that previously imagined.
"Our results indicate that achieving the goal of parity in STEM fields will take more than improving girls' science education and raising overall gender equality," they write. "The generally overlooked issue of intraindividual differences in academic competencies and the accompanying influences on one's expectancies of the value of pursuing one type of career versus another need to be incorporated into approaches for encouraging more women to enter the STEM pipeline."