A stronger argument comes from research into school results. Cirls grow up earlier than boys, tend to be more orderly and are likely to be better at languages. In a mixed class, boys who might do well in a single-sex class become discouraged and take on the role of troublemaker. Certainly in the UK the best schools are all single-sex , strongly suggesting that co-education is not the best answer. This may, however, not be as simple as it looks. It may simply be that the famous old schools that attract the best students happen to be single-sex, rather than that being single –sex make them better schools.

围绕学生的在校成绩而引发的争论更为热烈。女生比男生成熟得早，更守纪律，在语言方面成绩更突出。在男女混合的班级里，原本在单一男生班里表现出色的男生很可能情绪低落并扮演捣蛋鬼的角色。当然，英国最好的学校全是单一性别的学校，这明显说明男女同校教育并非上策。但也不能简单地一概而论，也可能是因为那些生源最好的老牌名校偏巧都是招收单一性别学生的，而不是因为招收单一性别学生才使它们成为名校。