Michael Egnor looks at such claims. Including apes as co-authors on a primatology research paper created quite a stir—among humans.
Anthropologists have gone back and forth as to whether animals grieve. They seem—almost as if intentionally—to miss the point.
Egnor: Dr. Pepperberg could have been more forthright: Parrots can’t do statistics. No animal (except man) can do statistics, because statistical reasoning is abstract and only human beings are capable of abstract thought. Parrots think concretely—they think of particular things and relations between particular things, but they cannot think without particular things—they can’t think abstractly.
Naturalists need to pretend that great apes and dolphins think abstractly.