CJO wrote: Jose, I can't believe you said it, though. It is terrible chauvinism to assert that sign language is not "true" language, that there's any barrier whatsoever between a speaker of a grammatical sign language and "abstract concepts." Sign languages are fully grammatical, and can handle any utterance that a spoken language can. They follow the pattern of "creolization" just as spoken pidgin languages do when a generation of children is brought up in a pidgin-linguistic environment.
You've got it backward. To acquire (a modern) language, a being must have a grasp of abstract concepts in the first place. Apes evidently don't. Therefore no ape has truly "learned" a language. (see post re: Nim Chimpsky above, and the comments of that researcher)
Thanks for de-lurking, CJO! I did not mean to imply anti-sign-language chauvinism, so I'm glad you brought it up. I agree entirely that the abstract concepts
that we have developed over the last few millenia are readily expressed by signing, and that true sign languages can be very complex. But, I don't speak of sign languages
that have developed alongside spoken language.
The trick for a non-speaking species is developing entirely abstract concepts in the absence of any fore-knowledge that they might exist, or any way of communicating besides making miscellaneous noises and motions.
I agree that it takes a capacity to think about abstract concepts before one can discuss them using language. However, my reading of the literature indicates that the consensus is that one (i.e. a species) must be able to communicate extremely effectively before they can move beyond concrete thought. Our pre-linguate ancestors (lacking the ability for speech) could probably plan hunts and fights, probably referring to several days' span as some number of "suns." They could probably use signing and stick-in-the-sand diagrams to map out strategies for dividing into groups and attacking from two directions at once. But could they talk about "truth"? Could they invent the concept of god, or heaven or eternity? Could they even consider the possibility of trying to figure out how reproduction works, with sperm fertilizing the egg, followed by cell divisions, differential gene expression, etc.? [I know, that's "science," but it's still conceptual, and beyond the grasp of those who cannot develop words for things they can't see.]
They were very good at transmitting skills to each other, such as flint-knapping. But this is, again, concrete and immediately-visible. It is unlikely that they could have looked at fossils, and thought about the world looking very different 70 million years ago. It's too abstract a concept. They could not have sat around asking "what the heck is this, and how did it come to be?"
So, you're right that no ape has truly learned a language, in the sense of not having learned to discuss philosophy. But if we're going to define "learning a language" as "knowing enough vocabulary and concepts to discuss lots of tough subjects," then I fear that we have to conclude that a vast number of humans haven't either. [For example, to write "informed consent" statements for humans involved in research projects,
one is required to use English at no higher than 8th-grade level. Even high school English is too complicated for great many Americans. I think reading at or below 8th grade level, as an adult, qualifies as not really having learned the language.]