I’ll grant you and the author that, but the disclaimer is a bit weak. It makes me consider now what I would dare to say about some other groups that I know, e.g. Russians and Germans. For example, I often say that Russians are superstitious. Clearly not all are superstitious, so what I am really saying is something like, “A large number of Russians are superstitious compared with other countries and relative to Russia’s level of educational and technological development.” Generalizations, simplifications, and other analyses necessarily introduce error. But here’s the irony: generalizing about blacks in the context of opposing racism. Lest anyone accuse him of being a white savior, blacks can also generalize about blacks, e.g. to support a position. I also do it.