People will perform all sorts of mental gymnastics to try to explain why genetics couldn't possibly be the cause of that, but none of those mental gymnastics seem to address why children with one white parent and one black parent have average scores right in the middle of the black averages and the white averages.
Black children adopted and raised by wealthy white people had an average adult IQ 17 points lower than adopted white children
https://en.wikipedia.org/wiki/Minnesota_Transracial_Adoption_Study#Results
People will perform all sorts of mental gymnastics to try to explain why genetics couldn't possibly be the cause of that, but none of those mental gymnastics seem to address why children with one white parent and one black parent have average scores right in the middle of the black averages and the white averages.