Re: Achievement and Illegitimacy
I think you overstate my claim and, in any event, I certainly acknowledge that there are other things that affect test scores besides illegitimacy. But illegitimacy is a huge factor, and it’s causally related to many other factors–not only lack of parental support and supervision in schoolwork, but poverty, getting into trouble with the law, substance abuse, you name it–that also affect academic performance.
I would be wary of relying too much on the failure of scores and legitimacy to move in the same direction at the end of the 20th century. During this period, we saw the dismantling of Jim Crow and the enactment of bans on discrimination in most public walks of life (including, of course, education). So we would expect there to be upward pressure on test scores during this time period. The fact that they didn’t improve more than they did suggests that something else must have been exerting pressure in the other direction, like the rise of illegitimacy and other and related countercultural mores (see John McWhorter’s Winning the Race).