Not necessarily. You haven’t accounted for differences in variance between the two groups.
Yes I have—see the next comment. If blacks with college degrees don’t have lower IQs than whites with college degrees, and blacks in general have lower IQ, then blacks without college degrees must have even lower IQs so that the average is still lower IQ.
Furthermore, taking other factors into consideration can result in worse discrimination. Consider the trait that most obviously makes up for the difference—actually taking an IQ test. Blacks may have lower IQ than whites, but blacks who take an IQ test and score X don’t have lower IQ than whites who score X at all. But if I were to hire people based on the trait “scoring X on an IQ test”, and X is at the high end, I may end up hiring a lot more whites than blacks—a small difference in IQ translates to a large difference in the number of people at the tail end of the distribution. If people with IQ 145 are 10 times as common as people with IQ 150 and the black curve is only shifted by 5 points, and I want to hire people with IQ 150, I may end up hiring whites to blacks at a 10 to 1 ratio compared to the proportion of blacks who apply.
Yes I have—see the next comment. If blacks with college degrees don’t have lower IQs than whites with college degrees, and blacks in general have lower IQ, then blacks without college degrees must have even lower IQs so that the average is still lower IQ.
Furthermore, taking other factors into consideration can result in worse discrimination. Consider the trait that most obviously makes up for the difference—actually taking an IQ test. Blacks may have lower IQ than whites, but blacks who take an IQ test and score X don’t have lower IQ than whites who score X at all. But if I were to hire people based on the trait “scoring X on an IQ test”, and X is at the high end, I may end up hiring a lot more whites than blacks—a small difference in IQ translates to a large difference in the number of people at the tail end of the distribution. If people with IQ 145 are 10 times as common as people with IQ 150 and the black curve is only shifted by 5 points, and I want to hire people with IQ 150, I may end up hiring whites to blacks at a 10 to 1 ratio compared to the proportion of blacks who apply.