Boy's math performance, compared to girls', jumps at age 6 (in the ELFE's data at least). We analyse here data from more than 10,000 (cross-sectional study) and 2000 (longitudinal study) French students aged 4-7 years, tested in the framework of the Etude Longitudinale Française depuis l'Enfance (ELFE). 
ELFE
Boy's math performance, compared to girls', jumps at age 6 (in the ELFE's data at least). We analyse here data from more than 10,000 (cross-sectional study) and 2000 (longitudinal study) French students aged 4-7 years, tested in the framework of the Etude Longitudinale Française depuis l'Enfance (ELFE). 
ELFE