Do black and white adult children of parents who attended graduate school have the same average IQs? Why shouldn't they? They had the same advantages that come from growing up in a home of highly educated parents.
Using GSS data, I calculated mean IQs (based on a vocabulary test) for blacks and whites whose mothers or fathers completed at least 17 years of schooling (20 years is the highest possible score).
Mean IQ (N = 546)
Has highly educated mother
Has highly educated father
* significantly lower than white counterpart
Even though these folks have equally educated parents, there is a gap between them that is roughly half of a standard deviation--a fairly large difference.
Our results fit just about perfectly a regression to the mean equation where heritability for IQ is set at 0.5; the mean IQ for educated parents is set at 115; and the means for the white and black populations are set at 100 and 85, respectively.