This point that spaghetti makes about internalizing incapability is huge.
I still remember an early adolescent student I had years ago who topped out the math reasoning section of my achievement testing--got only one or two items wrong, and did not hit a hard ceiling, on a test with norms up through college. This child should have been aiming for a top flight engineering school, but had been beaten down for so many years by school experiences that limited his options (and his view of himself) to the level of his reading disability (which was significant, but not severe) that we could not convince him that he was actually extremely intelligent and capable. Last I heard, he was working in an auto body shop, which is valuable and honorable work, but oh...
