At a Glance
- A massive study of over 2.5 million French children found that boys and girls enter first grade with virtually identical math skills, showing no initial gender disparity.
- After only four months of formal instruction, a statistically significant math gender gap favoring boys emerges and continues to grow throughout the elementary school years.
- The research demonstrated that the gap correlates directly with time spent in school rather than a child’s biological age, pointing to an educational rather than developmental cause.
- Data from a COVID-19 lockdown year, which resulted in less school time, showed that the math gender gap for that cohort grew by a smaller amount.
- These conclusive findings suggest that early math instruction is the critical area to investigate for solutions to prevent and close the gender gap in mathematics performance.
For decades, a question has persisted in education and psychology: Are gender differences in mathematical ability innate or learned? A massive new study of more than 2.5 million French schoolchildren provides one of the clearest answers to date. The research, published in the journal Nature, reveals that while boys and girls enter school with equal math skills, a significant gender gap favoring boys emerges and grows rapidly during the first year of formal education. This finding suggests that the classroom environment, rather than biology, is the primary driver of this disparity.
The research analyzed data from France’s national EvalAide assessment program, which tracked four consecutive groups of children entering first grade between 2018 and 2021. The results were stark. At the beginning of the school year, when most children were five or six years old, boys and girls had nearly identical math scores. However, after just four months of instruction, a statistically significant gap favoring boys appeared. This gap quadrupled by the start of second grade and continued to widen in subsequent years, pointing to a cumulative effect of schooling.
To isolate the cause, the researchers ruled out several alternative explanations. By comparing children of different ages within the same grade, they found the gap correlated strongly with months spent in school, not with a child’s biological age. This conclusion was further bolstered by data from the COVID-19 pandemic, which showed that a cohort experiencing shorter school years due to lockdowns developed a smaller gender gap than in other years. In contrast to math, a well-known literacy gap, where girls initially tested slightly ahead of boys, narrowed over the first year, indicating the effect is specific to math instruction.
According to the study’s authors, these findings shift the focus away from theories of innate biological differences or pervasive societal biases that would be present before schooling begins. The evidence strongly suggests that something within early math instruction itself may be inadvertently creating and amplifying this disparity. This pinpoints the first year of formal education as a critical period for intervention. The next step, researchers say, is to identify the specific classroom or curricular factors responsible, paving the way for evidence-based solutions to ensure equitable outcomes for all students.
References
- DeSmith, C. & Harvard Gazette. (2025, July 3). Large-scale study adds to mounting case against notion that boys are born better at math. Phys.Org; Harvard Gazette. https://phys.org/news/2025-07-large-scale-mounting-case-notion.html
- Martinot, P., Colnet, B., Breda, T., Sultan, J., Touitou, L., Huguet, P., Spelke, E., Dehaene-Lambertz, G., Bressoux, P., & Dehaene, S. (2025). Rapid emergence of a maths gender gap in first grade. Nature. https://doi.org/10.1038/s41586-025-09126-4
