There is data to suggest that, in early adolescence, girls suffer from reduced self-esteem. But there is no viable data to support the idea that this is due to events at school nor is there data to support that the self-esteem issue affects school performance. It is more likely that the drop in self-esteem in early adolescent females is related to their physical changes and the emphasis that society puts on the importance of women's appearance. Let's try a few facts. Girls consistently get better grades than boys all the way from elementary school through college.
More women attend college than men.
And, in a longitudinal study by the Department of Education, evaluating 25,000 8th to 10th graders, more girls than boys consistently expressed a sense of teachers being interested in them and listening to what they had to say. Boys outnumber girls in special education by five to one, boys drop out of school at alarming rates far in excess of girls, and, as the Sadkers' study actually demonstrated, young boys are reprimanded far more often than young girls. The elementary school boys that I have seen in my practice for more than two decades have complained of their female teachers favoring their female students. I also remember, from graduate school days, a study in New York City that showed a sharp reduction in the number of referrals for special education and in increase in grades for young boys when they had male teachers. School systems are very definitely not designed for young male children.