I was really referring to the point that parental involvement could help these poor kids achieve more than their IQ might reflect.
You are correct to some extent but the IQ test is measured in standardized tests in a society that is anything but standard across the board. Parental involvement could certainly improve the scores to a small degree in that respect. However, parent involvement through the learning process is priceless and may help the child in areas that standardized tests may or may not measure.
Face it, when the kid's dad is long gone and mom is a crack head, a child's future is very predictable. Not many teachers can overcome that.