A familiar saying is that if you find yourself in a hole, stop digging. That advice is particularly hard to take for the committed ideologue. One of the besetting problems of American society is the existence of large gaps in educational achievement, much of it correlated with race. This problem has attracted a lot of would be solutions, including, prominently, the Head Start program, and Affirmative Action.
If we accept that achievement differences are due to discrimination or existing economic and social discrepancies, interventions like Head Start sound reasonable. In fact, they have nearly always been a failure. The heart of this ideology is what has been called the "Blank Slate" - the notion that the brain is a blank slate upon which anything can be written. Evidence that this is not the case is derided as biased or worse. Not only that, but research into the biological underpinning of intelligence has been condemned as immoral - not for its practices or methods but because the results do not comport with the politically correct theory.
Meanwhile, evidence for the genetic basis of IQ, and its relatively high resistance to change, continues to accumulate. Some are starting to say that if you want interventions that work for reducing inequality, maybe you should stop relying on method that have repeatedly failed and look at the fact.
Alex Tabarrok has a post about Paige Harden, whom he calls a "left-leaning behavioral geneticist."