In "Affirmative Action: A Modest Proposal," I began by writing about the findings of a study which
shows that the income of a Korean orphan who was adopted in the U.S. between 1970 and 1980, through a process of random selection, is about the same regardless of the income of the adoptive parents. On the other hand, the income of the biological children of the same parents is highly correlated with the parents' income; that is, low -income parents tend to produce low-income children, whereas high-income parents tend to produce high-income children....
I went on to say this:
...The obvious implication of these findings is that intelligence (and hence income) is a heritable trait, one that remains differentiated along racial lines (a consistent but controversial finding discussed here, for example). Thus the findings give further evidence, if any were needed, that affirmative action policies -- whether government-prescribed or voluntarily adopted -- tend to undermine the quality of workplaces and educational institutions. (I am speaking here of the quality of effort and thought, not the value of workers and students as human beings.)
A reader objects -- sort of. He begins by saying:
[T]here's a flaw in your guest blogger's logic. He takes the adoption study as evidence that intelligence is a heritable trait and thus passed through racial lines (fine). He then says since affirmative action rewards racial minorities who may be less qualified (fine), that affirmative action tends to undermine quality of work.
[H]is conclusion may be correct, but is only tenuously related to the first premise. he seems to be saying that, on average, if you give preference to minorities, the quality of work will suffer, because on average minorities are less intelligent....
Let's stop right there and take things one step at a time.