And blackcat's thoughts highlight why the highest achieving low-income students struggle to fulfill their potential: they already meet or exceed performance goals for their subgroup (i.e. they are high-needs students who are achieving in the top performance classification on state-wide testing), so there is no institutional incentive to increase their achievement. It is true that their outcomes are likely to be better than their lower-achieving SES peers, but nowhere near their achievement peers, let alone their cognitive potential peers.
