Ce que la mixité fait aux élèves

The paper provides a synthesis of educational research devoted to the operating of co-educational classes, and assessing the impact of co-education itself. It relies on studies focussed on the interactions between teachers and pupils and between pupils themselves, and also those, less numerous, which compare single-sex and coeducational classes. It questions the impact of that way of operating upon pupils, with respect to the interpretations of social psychologists: actually, it proves that facing the ?other? increases the strength of the gender stereotypes, especially regarding self-confidence. In a last part, the text introduces a more normative debate upon the educational policies concerning co-education, since the latter does result, in spite of its obvious aspect, in ambivalent effects and seems to generate what would be a performative discrimination. The debate, which leads to discuss the question of coming back to single-sex classes ? even in a limited manner ? keeps quite open; that is because it relies in fine on conceptions of masculinity and femininity and on what equality means, which remains to day far from a consensual issue. JEL classification code: I10.