In any case, he's not even arguing about intelligence per se. Rather, he's supporting James Flynn's argument that IQ tests are flimsy instruments for measuring

In any case, he's not even arguing about intelligence per se. Rather, he's supporting James Flynn's argument that IQ tests are flimsy instruments for measuring intelligence. Flynn's argument is that kids from societies/households which require high abstract cognition (read: modernness) will score better on some of the IQ sub-tests (eg. similarities and abstract taxonomy). This suggests that kids can be "trained" to score well on IQ tests. There is more than socioeconomic factors at work here, and cultural factors (particularly those that influence cognitive modes of thought) are important. But ultimately, IQ tests are probably a dubious measure of someone's general intelligence anyway.