Why have people embarked on these Ape language studies? Some, it seems to me, go into these studies for the express purpose of proving that non-human primates cannot possibly learn language as we know it. Others seem to be biassed in favour of apes acquiring language. They may see things that an unbiased observer wouldn't see, or at least not gives as much importance to. In my search for answers, I haven't found much in the way of a middle ground. Each side of the debate is determined to prove the other side wrong. Is it possible that there is room for compromise? Both sides agree that these animals are communicating, but they disagree as to the extent of the communication as well as the particulars of what comprises language.
What exactly is language? These apes are communicating, but how do we determine whether or not what they are using is language. There are several required components of language. There has to be an intention to communicate. Using whatever medium is appropriate, there has to be meaning attached to the communication. These requirements are met in most species but they alone do not make up language. There also has to be a possibility of interchangeability, of the give and take of conversation. There must also be an ability to pass on this language from one generation to the next. I believe that all of these criteria have been met to some degree in ape language studies. There is the question of syntax that remains. It has yet to be proven that any of these apes have been able to master the complex grammar of our language. There has yet to be an ape that can create the complex and novel sentences that seem effortless even to a three or 4-year-old human child. (1)
Somewhere along the line, we had a common ancestor with the great apes. At some point there was a split between our ancestors as we became bipedal, developed tools and developed language capabilities while our relatives continued on all fours, in the trees. There is a debate whether the development of tools was a contributing factor to language development, or did language develop because we became bipedal causing physiological changes that made language production possible? What happened first? Did we develop larger brains because we were using them to develop tools? Or was it because we were developing language? There are anthropologists who go to great lengths to try to discover exactly when and how we developed speech. Because the soft tissue of the brain and vocal tract are not visible in fossils, however, it is very difficult to determine with total certainty exactly how all this occurred. The changes that took place, whether they were an adaptation or an accident of nature, must have happened slowly over time. Some believe that language evolved in such a way that the potential to comprehend language preceded the appearance of speech by several million years. It wasn't until we were fully bipedal, with all of the adaptations in our vocal tract in place, did we have the capacity to use consonants along with vowel sounds to make the units we call words. (2) What we do know for certain is that whenever and however language acquisition began in early man, it would bear little if any resemblance to the language we speak today. Patricia Greenfield, a linguist, thinks we may be looking at the ape language controversy all wrong. She believes that we should be looking at it from the ape's point of view. (3) Maybe instead of expecting an ape to master our language - a language that has taken us centuries to develop, we should be in awe that these intelligent creatures are able to learn to communicate with us at all!
In the many studies that have been done, the language acquisition of chimpanzees has been compared to that of a human child. Humans, it is believed, are hardwired for language. We can and, in most cases, do learn language with little effort or training. (4) One hypothesis of language acquisition is that there is a critical age during which this is likely to occur. It has been shown that after a certain age, usually associated with puberty, children are unable to acquire much of the syntactic component of grammar. (5)
Whether a child is deaf or hearing, language acquisition begins at an early age is pretty much parallel in its developmental stages. This has lead to the conclusion that there is more involved with language abilities than the ability to produce spoken words. Whether deaf or hearing, there are definite steps that children take on their way to linguistic competence. They begin with single words and advance to two, then three and more word combinations. The amazing thing to note is that even for human children, the rules of grammar and syntax don't all fall together at the same time. They may initially overgeneralize a word such as "dog" using it to refer to all animals that walk on 4 feet. At another stage of development, they may generalize that all plurals end in "s" producing such words as foots and sheeps. Words that they are said properly one day may suddenly change as they add new rules to their mental lexicon and learn to apply them. While they are on their way to perfecting their linguistic skills, they are listening, watching and learning to comprehend the world around them. As in prehistoric man, maybe comprehension comes first.
The left hemisphere of our brain is specialized for verbal or analytic processing. Humans attend to language sounds from birth. Studies show that even premature infants respond to subtle changes in language such as a change from "peck" to "pack". (6) Some people even believe that human embryo's hear what is happening in the world outside. I wonder if it is possible that humans begin to develop their ability for language while still in the womb? There is little doubt that we are genetically predisposed to language but is it possible that the development of the area associated with language ability forms partly because we are exposed to language from conception?
Apes have not as yet mastered our language. I'm not sure that they will ever do so. Genetically, chimpanzees and bonobos are very closely related to us. Is it so hard to believe then that they may share some of our language abilities? In some studies that have been done, chimpanzees have been brought into a human household with the express intention of giving them the same advantages of a human child in learning language. But if the human fetus start listening while still in the uterus, then an infant chimp brought into a human home may be at a disadvantage from the start.
In some studies such as with Washoe, only American Sign Language was used and not verbal language. If it is true that learning a language after the critical age of language acquisition means that we will have trouble learning the grammar of that language, is it possible that Washoe was at a disadvantage because her trainers were adults when they began learning ASL?
I have similar questions about studies that use coloured plastic chips and computer keyboards. These are not naturally occurring languages. They were fabricated for use with these apes. Have human used any of these methods as a sole means of communication? There are instances where boards with symbols are used to help disabled humans to communicate but this training does not instill language in children who have not acquired language in the first place, nor does it restore language to adults who have lost the use of language through strokes. As with apes like Sarah, the training provides constructions only. And yet, there seems to be every reason to take an optimistic view about the value of teaching language to those who have lost the capacity through accident, or those who never acquired it naturally. (7) Why is it that we think it's wonderful when a human regains a semblance of communication but only look for reasons to condemn the same progress in apes?
I believe as Robert Yerkes said, that the great apes have plenty to talk about (8), they just haven't as yet the ability. With the ongoing research into ape language, maybe someday we will know what goes on inside the mind of an ape.
An Introduction to Language pg. 405
Language Comprehension in Ape and Child (1993)
Kanzi pg. 156
An Introduction to Language pg. 403
An introduction to Language pg. 392