Well, that's not quite what they're saying - essentially what they're saying is that they're a different kind of smart. Not that I agree with the logic, but essentially what they're saying is that the tests - along with the whole curriculum - were designed and written by white people, so they're unintentionally biased in a way that non-white people (except, I guess, asians) can't understand them. The implication being, of course, that if black people had designed the entire curriculum and the tests, they would be similarly impenetrable to white people. Of course, I don't think that makes much sense either, but that is the essence of what they're trying to assert.