21/03/2026
🧵 Does the teacher's gender affect the math gender gap? Yes — but the mechanism matters more than the match.
1/ Same-gender matching (Dee, NBER 2006): assigning a student to an opposite-sex teacher lowers performance by ~0.04 SD. A year with a female teacher can close the science gender gap in 13-year-olds by half — and eliminate the smaller math gap entirely.
2/ But the bigger story: math anxiety in female teachers (Beilock et al., PNAS 2010). 90%+ of primary school teachers in Western countries are women. When female teachers have high math anxiety, girls in their class underperform — boys are unaffected.
3/ The mediator: girls internalize the stereotype "math is for boys" transmitted by anxious female teachers. A male teacher with math anxiety does NOT produce the same effect in girls.
4/ Implicit bias in grading (cross-national, 2023): teachers systematically rate boys higher in math and girls higher in language — even controlling for actual performance. These biased assessments partially mediate later achievement gaps.
5/ Implicit stereotypes (Carlana 2019): teachers with stronger implicit gender-math stereotypes steer girls toward less math-intensive tracks. Girls taught by these teachers also show lower math self-confidence.
📊 Summary:
• Direct gender-match effect: modest (~0.04 SD)
• Teacher math anxiety → girls only: significant year-end gap
• Implicit grading bias: domain-specific, both sexes
• Stereotype-driven track advice: girls, long-term impact
Bottom line: it's less about whether the teacher is male or female, and more about what beliefs they transmit — consciously or not.
