What can other great apes really do?

[Hatshepsut]

On the other hand, there are plenty of sceptics who think that while those who work with these apes may not be consciously lying, they may have fallen pray to biases. This situation would then be similar in nature to the facilitated communication fiasco...

I don't think Susan Savage-Rumbaugh's "Ape Talk" board is an instance of facilitated communication. Sue isn't sticking her paw on the ape's hand to guide its choices of lexigrams. The apes know how to communicate using these boards not only with their keepers, but with some of their fellow apes.

There is a real question of whether what the apes are doing should be called language in the human sense of that word. Apes frankly aren't very good grammarians. They are aware the buttons represent things and actions, that two or three buttons can be combined to qualify or connect things or actions more precisely than a single button does, and that the order the buttons are pressed matters. These are elements of language, syntax for instance: After all we can't say our speech faculty has no precedents in the animal world.

But "Ape Talk" isn't a true language. Noam Chomsky and other linguists stress that grammar is generative. A sentence not only conveys a message, but it has a structure based on implicit rules such that the listener can tell whether it is grammatical or not. "John walked a fine line" is grammatical to English speakers while "John walk fine line" is not, even though the latter sentence is syntactically in order. English requires function words like "a" and functional morphology like -ed or -s to be inserted here. Words and phrases in a real language have gender, number, tense, aspect, mode, and so on that are crucial to meaning yet absent from the "Ape Talk."