I largely agree with Derbyshire's premise that public education in the U.S. is "basically a series of rent-seeking rackets." That's the first third of the article and, I believe, it's a largely accurate statement of the folly of our current system.
Then Derbyshire goes on to criticize Paul Tough's notorious NYT article, like most of the edusphere has already done, and then proceeds to demolish the "blank slate" theory of human cognition. And, it's hard to argue with this observation:
In the end, all left-liberal prescriptions for educational improvement end up with two demands: that governments should spend more money on schools, and that parents should work harder at parenting.
But, I disagree with Derbyshire's implication that there's not much we can do educationally for those students who've been dealt a bad genetic hand of cards.
Having a low IQ doesn't mean that you can't learn. It just means that you need to be taught better and more efficiently. This we've known how to do for at least 30 years and counting. It doesn't necessarily take super teachers working 16 hours a day to accomplish either. Nor does it require more money. It doesn't even require more parental support. (Though certainly having these things isn't going to hurt.)
Where Derbyshire goes wrong is thinking that IQ represents what we've learned , rather than a person's capacity to learn:
And we then, having reached adulthood, regress a little to our pre-ordained shape, like one of those peculiar alloys. It is a curious fact, well supported by a mass of evidence, that the heritable components of our personality and intelligence become more marked as we age. The IQs of 40-year-olds correlate better with those of their parents or siblings than do the IQs of 20-year-olds.
This may very well be true, but the fact that a student's IQ will regress isn't going to affect what the student has learned in the meantime.
The only educationally significant difference between the low performers and high performers is the rate at which they learn new information, the clarity of the teaching presentation needed to teach the new information, and the amount of practice needed to retain the learned inofrmation. In terms of education, having a low IQ is like being a short basketball player--it limits your ability to be competitive with the tall players, but you can still learn how to play basketball.
The low IQ kids will hit the point where additional learning become too much of an effort to be a productive endeavor. Derbyhire's mistake is thinking that this occurs at the 3R stage instead of the rocket scientist stage. It's not like we don't have counterexamples of low-performers receiving good instruction outperforming high-performers receiving worse instruction.