I’d challenge McWhorter to explain Chicago and its murder/shooting rate without using race and IQ.
We are often taught, as the enlightened and even scientific verdict, that blacks and whites occupy radically different environments today, and that these differences can explain the entire black–white IQ gap. Under this analysis, there may be a heritable part of IQ that differs between the races, but, first, it is small, and second and more important, environmental factors override its effects. This is the main takeaway from a recent article in Vox by the IQ researchers Eric Turkheimer, Kathryn Paige Harden, and Richard Nisbett. Specifically, they point to evidence that environmental changes, such as a child’s adoption into a better-off family, can produce IQ gains as big as the average difference between blacks and whites. Poor schooling, plus the general stresses occasioned by a hardscrabble existence, depresses IQ in ways we all intuitively understand.