Despite decades of debate, a new international study may have finally cracked the mystery behind gender gaps in mathematics, and it doesn’t point to biology or bias at birth. Instead, the culprit may be something far more familiar: the classroom.
A sweeping new paper published in Nature reveals that boys and girls begin formal schooling with nearly identical math abilities. But within just four months of instruction, a small gap favoring boys appears, and it keeps growing with each school year.
The study, co-authored by renowned cognitive psychologist Elizabeth Spelke and a team of European researchers, draws on data from over 2.5 million French schoolchildren. It’s the most comprehensive evidence yet that gender disparities in math are not hardwired but somewhat shaped by early educational experiences.
Spelke, a longtime advocate for gender equity in science, has spent decades studying how infants and young children understand numbers and space. Her conclusion?
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“There are no differences in overall intrinsic aptitude for science and mathematics among women and men.“
That claim now has even more substantial backing. French children entering first grade between 2018 and 2021 showed virtually no gender difference in math skills, a finding consistent with earlier U.S. studies on smaller scales. But by the second grade, the gap had quadrupled. By sixth grade, it was even wider.
So what’s happening in those early months of school?
The study points away from innate ability or even early parental bias. If boys were naturally more inclined toward numbers, researchers argue, the gap would show up before school began. Instead, the data suggests that something about how math is taught, or how students experience it, is subtly shaping performance along gender lines.
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Interestingly, the gap didn’t grow as much for the 2019 cohort, whose school year was cut short by the COVID-19 pandemic. Less time in school meant less divergence in math scores, a surprising twist that further implicates the classroom environment.
Spelke and her collaborators aren’t just diagnosing the problem; they’re working on solutions. In partnership with Nobel laureate Esther Duflo and the nonprofit J-PAL, Spelke is helping design and test new math curricula for young learners in India. The goal is to create early math instruction that’s not only effective but also equitable.
Meanwhile, in France, the Ministry of Education is using the findings to refine its national assessments and curriculum. The hope is that by identifying exactly when and how the gap emerges, educators can intervene before it becomes entrenched.
Journal Reference
- Martinot, P., Colnet, B., Breda, T., et al. Rapid emergence of a math gender gap in first grade. Nature (2025). DOI: 10.1038/s41586-025-09126-4
