Well I have just my example and the examples of my friends. Then I made a theory. Boys fails more than girls in middle school because of low discipline. 50 years the disipline was harsch and boys succeed Now it is too lax. I have one son and two daughters. I had to punish my son a lot to make him do his home work and to read. I had not this problems with mu daughters. They did it without me asking. The other mothers told the same to me. It was very hard to make their son read. So my theory is that boys less succeed than girls because education has become too lax and that with boys you have to be very strict. It worked for me, my son is very good.