“..the study found that stereotypes seemed to be holding boys back.”
So boys are basically being graded on their behavior, not their merit. They have different styles of doing homework and don’t sit still in class. Teachers often hate this and reward girls for their conformity to their rules and penalize boys for their non-conformity and behavior. Teachers can no longer discipline in school, and the only punishment is often suspension. I wonder how the lack of discipline has played a role in teacher’s using grading, perhaps subconsciously to punish boys.