Kanzi: The Ape at the Brink of the Human Mind by Sue Savage-Rumbaugh Page B

encouraging and/or helping the ape to make the sign or to select the correct symbol. Once the ape could do this on its own, additional signs or symbols were introduced to build vocabulary. It was assumed that teaching words in this way was a rather simple process, if somewhat time-consuming. It was also assumed that such training basically depended on forming conditioned stimulus response associations between items and symbols. The real test of language, it was said, would come when one looked to see if apes could put together sentences from the words they had learned.
    While this sort of word learning may lead to sentence production in adults who are learning a second language, it is not at all the way children go about learning their first language. However, at that time, very little research on how children actually learned words had been done. It seemed reasonable, therefore, to start by teaching apes word-symbol associations. It had also seemed to work.
    Unfortunately, the process did not work with Sherman and Austin. With only one symbol available to be selected, Sherman and Austin learned relatively easily, as would be expected. If we held up a banana, they selected the banana symbol, as that was the only one available. With two, a lot more practice was required, but eventually they succeeded. Beyond two, however, the chimps became hesitant and failed to improve, no matter how much practice we gave them. The chimps were clearly puzzled as to how to proceed. I was puzzled, too, because Washoeand Lana had encountered little difficulty in learning associations between objects and symbols or signs.
    I watched videotapes of training sessions to see if I could figure out what we were doing wrong. The problem was that I had not stopped to ask why a chimpanzee who had had no previous language training would know that symbols encoded anything. I expected the chimp to make an association between the object and the symbol—and thus know the object’s name. Instead, as I learned from close scrutiny of the videotapes, Sherman and Austin were paying attention to the symbol and my subsequent action—that is, whether or not I gave them a reward.
    No wonder we were all confused—humans and chimps alike. We all had different views about what was going on. As teachers holding up objects, we assumed that the object we were showing the chimp would serve as the “stimulus object” since it preceded the response. The chimps, however, were assuming that the symbol-key they selected served as the “stimulus” for us to give them food. They looked for a link between the symbol they depressed and whether or not we elected to give them food—and if so, what sort of food. They paid no attention to the “stimulus item” we displayed. Indeed, they paid no attention even when we attempted to cue them by pointing back and forth repeatedly between the stimulus item and the correct lexigram.
    In hindsight, this seemed obvious. Why should they care what we were showing them? They cared more about whether we were tickling them, chasing them, feeding them, and so forth. Once it was apparent that the chimps were attentive to the consequences that followed their symbol production, rather than to the stimulus conditions that preceded it, it suddenly dawned on me that the Gardners had essentially taught Washoe “names” by giving her the object or action
after
she made the sign. Thus, if she signed
tickle
, they tickled her, if she signed
banana
, they gave her a banana. Similarly, when Lana depressed
Please machine give piece of banana
, she got a banana; when she said
Tim tickle Lana
, Tim did so—at least he did so at first while Lana was initially learning. However, this fact had notbeen pointed out in articles. Instead, it had been emphasized that Washoe and Lana had learned the names of things by being shown the objects they were to name.
    After it became clear that the contingencies which followed symbol use made all the difference, we