Ah I should have stopped reading after your first sentence, because the next sentence suggests the broader point you're getting at is that difference in test scores is attributable to mostly economic factors. Here is your second sentence:

> I suspect test scores corelate more strongly with household income and wealth than with race.

The question of whether people in higher socio-economic class score higher in standardized tests is obviously true and uninteresting. The real question is if the correlation trumps other factors like race (which you hinted at by your next sentence). Kind of like asking "is this SUV safe for a Toyota". Obviously its safer than smaller Toyota vehicles, the pertinent question is whether its safe compared to other SUVs.

So yes, students in higher economics. You can google 'socio-economic test scores'. Here's a top result:

> Socioeconomic status (SES) and SAT scores are positively correlated: Students from higher income backgrounds generally achieve higher scores, and “21.2% of variance in SAT scores is shared with SES, as measured here as a composite of mother’s education, father’s education, and parental income.” The researchers note that the “source of the SAT-SES relationship is likely due to some combination of educational opportunity, school quality, peer effects and other social factors.”

https://journalistsresource.org/economics/ses-socioeconomic-...