A new study published in Psychological Science revealed that sex differences in intraindividual academic strengths—favoring girls in reading and boys in mathematics and science—are larger in more gender-equal and wealthier countries.
Over the past decades, gender disparities in science, technology, engineering, and mathematics (STEM) fields have persisted, even in countries with high levels of gender equality. Despite educational advancements, women are underrepresented in many STEM disciplines. Previous research has documented a “gender-equality paradox,” where sex differences in academic preferences and STEM participation are more pronounced in gender-equal countries. This paradox challenges the expectation that greater gender equality should reduce sex differences in occupational and educational choices.
Marco Balducci and colleagues set out to explore this paradox further, focusing on intraindividual academic strengths—comparative academic advantages within individuals—rather than overall achievement.
The researchers used data from five waves of the Programme for International Student Assessment (PISA), conducted between 2006 and 2018. The PISA is an international assessment that evaluates 15- and 16-year-old students’ abilities in reading, mathematics, and science. To ensure a comprehensive analysis, the researchers included data from 2.47 million adolescents across 85 countries and regions, making this one of the largest studies of its kind.
The sample was drawn using a representative, two-stage sampling method for each country, first selecting schools and then students within those schools. Participants were administered the PISA assessment, which includes items across the three core academic areas of mathematics, reading comprehension, and science literacy.
Since administering all PISA items would take over six hours, students were randomly assigned a subset of items, allowing for comprehensive assessments in each domain. The scores from these tests were then standardized within each country and PISA wave to calculate individual strengths.
Specifically, the authors computed the students’ best, second-best, and lowest academic scores, relative to their average academic performance. The differences between these scores provided an estimate of each student’s intraindividual academic strength. The researchers also incorporated country-level data on gender equality using the Global Gender Gap Index (GGGI) and measures of wealth from the PISA family wealth index, ensuring that they could explore relationships between these variables and sex differences in academic strengths.
The findings revealed stable sex differences in academic strengths across the five PISA waves, with girls consistently showing an advantage in reading, while boys demonstrated strengths in mathematics and science. These differences were observed consistently across the globe. Interestingly, while boys and girls had similar overall average scores in some contexts, their relative strengths diverged.
For example, boys were more likely to exhibit strengths in mathematics and science as their best-performing subjects relative to their overall performance, while girls showed stronger comparative performance in reading. These sex differences remained stable across the 12-year study period, indicating a persistent pattern.
Interestingly, these sex differences were more pronounced in countries with higher levels of gender equality. In nations that scored higher on the GGGI, boys exhibited even stronger strengths in science relative to girls, while girls’ advantage in reading became more pronounced. This pattern held true across all five waves of PISA, suggesting that as gender equality increased, so too did the gap in academic strengths between boys and girls.
Additionally, the researchers found that wealthier countries exhibited similar patterns, with the gender gap in reading strengths favoring girls and the gap in science strengths favoring boys widening as wealth increased.
These results support the idea that as countries become more gender-equal and economically prosperous, personal interests and intraindividual strengths play a larger role in shaping educational outcomes, further exacerbating sex differences in academic preferences.
The authors acknowledged that the correlational nature of their study limits the ability to draw causal inferences. They also noted that while the GGGI is a comprehensive measure of gender equality, it may not capture all relevant aspects of gender equality that affect educational and occupational choices.
The research, “The Gender-Equality Paradox in Intraindividual Academic Strengths: A Cross-Temporal Analysis”, was authored by Marco Balducci, Marie-Pier Larose, Gijsbert Stoet, and David C. Geary.