No, he's saying that liberalism and conservatism also come with sets of beliefs about the nature of reality and sets of predictions about the consequences of their actions. Some of which are wrong (for both groups). And he's saying we should be able to guess which group has a better understanding of the world by comparing their IQs. Which I think is a valid point, except that the example he chose is one where IQ clearly creates a bias of its own, and one where black people probably miscategorise themselves.