It was really bad when I was in 6th grade and he was in 4th.
He had same teacher I had and she and I never got along - so 2 years later she took it out on him.
I was a straight A student, my brother wasn't.
By October I knew what was going on but it took until December before the principal finally acknowledged that I had a legitimate point, and nearly February before anything was done about it.
Even at the age of 11 I was an activist!!!!!!