Education can raise how much everyone knows, but it almost never changes who is ahead of whom.

Writer with a PhD in English who taught writing for years

Decades of grading data; standardized test scores; cross-sectional, longitudinal, observational, and experimental studies; along with many other types of ancillary and convergent evidence, ultimately tell the same story: education can raise the absolute performance of most students modestly, but it almost never meaningfully reshuffles the relative distribution of ability and achievement