In discussions on coeducation in France, two opposite positions can be picked out: on the one hand coeducation would be an equality factor between the sexes; on the other hand, it would increase the sexually stereotyped attitudes between students of both sexes. The study on graduates from the first coeducational cohorts to graduate from the ENS Fontenay, Saint-Cloud and Lyon reveals that those effects are different according to their specialization (science or humanities) or the kind of test (written or oral). With the results of this survey, it’s possible to discuss and formulate different hypotheses about the sexual differentiation of scholar behaviour or scholar success in a coeducational context.