Can a good enough school actually close the gap between high and low IQ kids or is that just something we tell ourselves to feel better about education policy?
I keep hearing that the solution to academic achievement gaps is better schools, better teachers, better funding. And I get why that is a politically appealing argument. But I also know that IQ is highly heritable and predicts academic outcomes really strongly. So can schools actually make every kid academically proficient or is that goal fundamentally unrealistic given what we know about cognitive ability distributions?
This is essentially the training hypothesis applied to education, and the evidence is not encouraging for the strong version of the claim. Schools can raise the floor and good early interventions produce real gains, especially for kids from disadvantaged backgrounds. But the gap between high and low ability students does not reliably close with better schooling. Higher ability kids tend to benefit more from enriched environments too, which means better schools can actually widen outcome gaps even while lifting everyone. Universal proficiency assumes a normal distribution of ability can be pulled above an arbitrary threshold through instruction alone. Large scale evidence suggests that has hard limits.
The more defensible goal is making sure every kid reaches their own potential, not that every kid reaches the same destination. Those are very different targets and conflating them leads to bad policy and a lot of frustration for teachers who get blamed for gaps they cannot close.