A Michigan State University report details the fact that boys are more likely to be punished in school for behaviors girls are let off the hook for:
"boys are more likely to be scolded and reprimanded in classrooms even when the observed conduct of boys and girls does not differ (Sadker, Sadker, and Long,1993). Additionally, boys are far more likely to be identified as exhibiting learning disabilities, reading problems, and mental retardation. They also receive lower grades, are more likely to repeat grades, and are less likely to complete high school."
"MOTIVATIONAL THEORY AND THE MIDDLE SCHOOL" pg 11
This is one of the BIG reasons why boys are having much more of a difficult time in school than girls and it is the underlying cause that no one wants to talk about.