That is, they capture race but not other socio-economic information from the test-takers.

I suppose my point is, on a truly standardized test (if such a thing exists), there ought not be differences by race, sex, or socio-economic class.

However, it's hard to picture any test, however fashioned, whose outcome is unaffected by parental encouragement, school quality, nutrition, and other factors that are likely to be correlated with the variables which you mention.

The SAT and ACT test intelligence, but also test academic achievement, and academic achievement is correlated to a certain extent with social circumstances of upbringing.