You are making some excellent points. You are highlighting the difference between native intelligence versus academic achievement.
I remember a psychology study I read in college. The scientists went to the teacher and said, "these 3 children have had their IQ tested and they are on a verge of a big intellectual break-through." Then they said, "these 3 kids were tested and they are of average IQ."
Actually, all the kids had the exact same IQ.
They followed the kids and retested them a year later. The kids who were supposedly gifted (but really weren't) scored much higher on the subsequent IQ test; the "average" kids, who were actually the same, scored much lower.
They had placed TV cameras in the classrooms and they found that, unwittingly, the teachers spent more time, praised more, etc. the kids who they thought were gifted than those they thought weren't. When they interviewed the teachers, the teachers said they spent the exact same amount of time with each kid, although they actually were not.
