The Gender Equality Paradox for Personal Academic Strengths

New research on the causes of STEM gender gaps

Photo by Jessica Lewis 🦋 thepaintedsquare on Unsplash

In this post, I’d like to summarize a fascinating recent paper by Marco Balducci, Marie-Pier Larose, Gijsbert Stoet, and David Geary, published in the journal Psychological Science. The paper looks at the completely uncontroversial issue of the causes of gender gaps in STEM. It concludes that one contributing factor is that boys and girls differ in their personal academic strengths - that is, in which of their subjects earns them their highest grades. For girls, it’s typically reading; for boys, it’s more often math or science.

Sex differences in academic strengths are highly consistent across nations and time. Moreover, they tend to be larger, rather than smaller, in more gender-equal nations - an example of the gender-equality paradox, and the opposite of what we’d expect if the differences were due to gender roles or patriarchy.

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Explaining Gender Gaps in STEM

Much has been written about the causes of sex differences in STEM - the fact, for instance, that more men than women go into inorganic STEM fields, whereas more women than men go into the health sciences. The main explanations for the discrepancies fall into three categories:

1. Bias and barriers

2. Sex differences in career-related interests and lifestyle preferences

3. Sex differences in cognitive strengths

The third category - sex differences in cognitive strengths - is the most controversial, but also the one where we find the smallest average differences. A common argument in the past was that boys are inherently better than girls at math and science, and that that’s why more men than women go into most STEM fields. Recent data reveal, however, that average math and science gender gaps have narrowed considerably over the last half-century, and that while boys still do better in these subjects in some countries, in others, we find either no sex differences or that girls do better.

But although average sex differences in math and science are modest at best, sex differences in personal academic strengths might still be important. For example, more boys than girls could have math or science as their best subject, even when girls are doing as well or better than boys in these domains. Likewise, more girls than boys could have reading as their best subject, even if they match or exceed boys in math and science.

If that’s right, then sex differences in personal academic strengths could prove important in explaining STEM gender gaps.

The Study: 2.5 Million Students from 85 Nations

To explore these complex issues, Balducci and colleagues looked at five waves of data on academic competencies from the Programme for International Student Assessment (PISA). The data covered nearly 2.5 million adolescents from 85 nations and spanned the years 2006 to 2018 - a remarkably large and diverse sample by any standard. Crunching the numbers, the researchers came away with three main sets of findings.

1. Average Sex Differences in Academic Competencies

The first set of findings explored sex differences in academic competencies. As the following graph makes clear, averaging across countries, girls did considerably better than boys in reading comprehension in all five PISA waves, while boys did somewhat better in math in all fives waves, and slightly better in science in three waves.

Standardized mean sex differences (± SEM) in mathematics (green), reading comprehension (red), and science literacy (blue) across PISA waves. Positive values indicate an advantage for boys, and negative values an advantage for girls. PISA = Programme for International Student Assessment.

Breaking the data down by nation revealed important hidden details about the nature of the sex differences. Not only did girls do better in reading overall, they did better in every nation without exception. In contrast, boys’ advantages in math and science were much less consistent: In many nations, there were either no sex differences or girls had the upper hand.

In short, although we tend to worry more about girls’ disadvantages in math and science, boys’ disadvantage in reading is much larger and more consistent.

Given that average math and science sex differences aren’t huge, and that they’re absent or reversed in many nations, the differences presumably have at most a modest impact on gender gaps in STEM. The reading sex difference, in contrast, may be a significant contributor. People with a relative strength in language are more likely than their less linguistically gifted counterparts to go into language-oriented non-STEM fields. Because more women than men meet this description, more women than men go into those fields - and thus fewer women go into STEM.

2. Sex Differences in Personal Academic Strengths

The next set of findings were the center of the bullseye for the study: They focused on female-male differences in personal academic strengths. As expected, while boys and girls didn’t differ much in their math or science abilities, boys were notably more likely to have either math or science as their personal academic strength. Girls, on the other hand, were much more likely to have reading as their personal academic strength, even when they were just as good or better than boys in math or science.

The findings are shown in the following graph. On the left, we see basic sex differences in reading (red), math (green), and science (blue) across a range of nations. On the right, we see sex differences in personal academic strengths.