By guest blogger Louisa Lyon

In many countries, the proportion of girls opting to pursue careers in lucrative fields such as engineering and computer science has stagnated. Despite the best efforts of schools, universities and governments, women remain underrepresented in science, technology, engineering and mathematics, the so-called “STEM” subjects. The shortage of women is particularly acute in professions with a heavy focus on maths. But why?

A recent study in PNAS suggests that the answer may lie in differences in ability between boys and girls. But surprisingly, the ability in question is not maths, but reading. In a nutshell, girls who are good at maths tend to be even better at reading, and as a result, many turn away from maths and opt instead to pursue careers that utilise their even stronger language skills. By contrast, boys who are good at maths tend not to show this same advantage in reading, making their decision to stick with STEM subjects much more straightforward.

The authors of the study, Thomas Breda and Clotilde Napp, who are based at universities in Paris, uncovered this effect while analysing data from the Programme for International Student Assessment, better known as the PISA study. Every 3 years, hundreds of thousands of 15-year-olds in 34 mostly developed countries and 30 developing countries complete the PISA test, which measures ability in maths, reading and science. It also asks pupils to indicate whether they intend to pursue a maths-based career.

Analysing the 2012 PISA data, the team found that boys outperformed girls in maths. However, the difference between the sexes was relatively small. Using a form of statistical analysis called linear regression, which explores whether changes in one factor can explain changes in another, the pair confirmed that neither differences in maths ability nor differences in reading ability alone could explain the gap in the proportion of boys and girls who stated that they intended to pursue maths-based careers.

However, the story changed when instead of examining reading and maths ability in isolation, the researchers instead considered how well each individual performed in maths versus reading. This “difference” measure could explain the gender gap. Essentially, girls who scored highly on the maths test were far more likely than boys to do even better on the reading test. As a result, many more of the girls faced a choice between two types of careers.

Does it matter if fewer women than men choose to work in maths-based fields? Earnings in such professions tend to be relatively high, thus the shortfall of women in these fields is likely contributing to the gender pay gap across society as a whole. It might be the case that 15-year-olds are not fully aware of these differences in earning power. If so, providing students with more information about the financial benefits of different career paths could potentially increase the number of women opting for maths-based careers.

But it is also possible that women and girls are simply prioritizing factors other than money when choosing a career. The percentage of women taking degrees in STEM subjects is lower in countries with greater gender equality. Countries with high gender equality tend to be relatively affluent and to have strong welfare states. This suggests that women may be more likely to choose careers based on their personal preferences when their overall financial situation is better. Breda and Napp saw a hint of this in their own study, where the gender gap in maths-based career intentions was slightly larger in mostly developed countries than in developing countries.

Society as a whole, however, would stand to benefit from expanding the available talent pool for engineering and computer science. The decisions made by software engineers will shape many aspects of the future for us all. But just as women may be at greater risk of injury in road traffic accidents because crash-test dummies are based on the average man, so technology may end up catering better to men than to women if the vast majority of computer programmers are male.

– Girls’ comparative advantage in reading can largely explain the gender gap in math-related fields

Post written by Louisa Lyon for BPS Research Digest. Louisa spends half her week as commissioning editor for the neurology journal Brain, and the other half as a freelance writer and editor.

At Research Digest we’re proud to showcase the expertise and writing talent of our community. Click here for more about our guest posts.