http://rankingwatch.blogspot.com/2020/06/the-great-acceleration.html is one blogger’s observation

Standardized testing has long been a problem here. Tests like the SAT, ACT, GRE, LSAT, and GMAT  are good predictors of academic ability and cognitive skills but they invariably give better scores to Whites and East Asians than to African Americans, Hispanics and Native Americans.

For many years there have been repeated demands that American universities abandon objective testing for admission and placement. One element in these demands was the observation that there was a correlation between family income and test scores. This was attributed to the ability of rich white parents to provide expensive test preparation courses for their  children.

There was an element of hypocrisy in these claims. If test prep courses were the cause of racial differences why not just make them a required part of the high school curriculum or pay the test center fees and travel costs of low-income students? The failure to propose such measures suggests that everyone knows that this is not really the cause of racial or social achievements.