That could be verified by looking at first-generation SAT takers, eg immigrant families or perhaps historical data from when SAT wasn't so common in the US. It seems extremely intuitive to me that families with higher income raise children that have higher SAT scores though.
Precisely my point. By my reading it appears that the only empirical evidence for race-based discrimination (an extraordinarily grave accusation) is something that could just as easily be explained by factors other than racism.
But this is no defense of those elite institutions, mind you. I'd even go so far as to make an exception and tax the staggering returns on their endowments.
Causation is measure of the extent to which they contain different information.
Assuming a college wants to admit a student with high "intelligence" or intellectual potential, which cannot be measured directly.
If high income causes high SAT, and high intelligence also causes high SAT, then (low income, high SAT) may well indicate much higher intellectual potential than (high income, high SAT)
If high income and SAT are both caused by high intelligence, then there is less (intelligence-related) reason to prefer (high income, low SAT) or (low income, high SAT).