The Articulate Mammal (10 page)

At first sight, Nim’s sign sequences were impressive. Of the 20,000 recorded, approximately half were two-sign combinations, and 1,378 were different. A superficial look at the signs suggested to Terrace that they were structured (Terrace 1979a: 72). For example, of the two-sign utterances which included the word MORE, 78 per cent had MORE at the beginning as in MORE TICKLE, MORE DRINK, and of the two-sign utterances involving a transitive verb (a verb which takes an object), 83 per cent had the verb before the object, as in TICKLE NIM, HUG NIM. But a closer analysis showed that the appearance of structure was an illusion. Nim simply had a statistical preference for putting certain words in certain places, while other words showed no such preference. He preferred to put the word MORE at the beginning of a sequence, the word NIM at the end, and any foods he was requesting at the beginning also. But many other words had a random distribution. Take the word EAT, a high frequency item in his vocabulary. It occurred in the two-, three- and four-sign sequences set out in the tables below.

It would require a considerable amount of imagination and wishful thinking to detect a coherent structure in such a collection. Looking at the two-sign sequences, we note that EAT NIM, NIM EAT and ME EAT are all very common, making it impossible to claim that there is a firm subject–verb, or verb–subject order. A similar pattern occurs in the three-sign sequences, with EAT ME NIM, NIM ME EAT, ME NIM EAT and EAT NIM ME all occurring a significant number of times. It is particularly noticeable that Nim’s longer utterances were not in any way more interesting and sophisticated than his shorter ones – they were simply more repetitive. Of the thirteen four-sign sequences noted above, ten of them involved repeated items, and five of them were simply a doubling up of two-sign utterances: EAT DRINK EAT DRINK, EAT NIM EAT NIM, DRINK EAT DRINK EAT, NIM EAT NIM EAT, ME EAT ME EAT. Nim’s longest recorded utterance was a sixteen-sign sequence which involved only five different signs: GIVE ORANGE ME GIVE EAT ORANGE ME EAT ORANGE GIVE ME EAT ORANGE GIVE ME YOU. On this evidence, it seems incontestable that ‘Repetitive, inconsistently structured strings are in fact characteristic of ape signing’ (Petitto and Seidenberg 1979: 186).

Terrace found a number of other differences between Nim’s signing and true language. For example, when Nim was just over 2 years old, 38 per cent
of his utterances were full or partial imitations. Almost 2 years later, the number of imitations had gone up to 54 per cent. Nim was producing more imitations as he got older, the reverse of what happens with human children. Nim was also unable to grasp the give-and-take of conversation, and his signing showed no evidence of turn-taking. Furthermore, he rarely initiated conversations. Only 12 per cent of his utterances were truly spontaneous, and the remaining 88 per cent were in response to his teachers. We may conclude, therefore, that Nim did not use his signs in the structured, creative, social way that is characteristic of human children. It seems reasonable to agree with Terrace that ‘It would be premature to conclude that a chimpanzee’s combinations show the same structure evident in the sentences of a child’ (1979a: 221) and that ‘Nim’s signing with his teachers bore only a superficial resemblance to a child’s conversations with his or her parents’ (Terrace 1983: 57).

Somewhat surprisingly, this conclusion has been fiercely challenged. Terrace’s critics point out that Nim was a highly disturbed young chimp. Due to frequent changes in those who taught him, Nim was insecure and maladjusted. They claim that his achievements are considerably lower than one might expect from a ‘normal’ animal. Others have argued that a computer analysis of chimp utterances that takes no account of the actual situation is bound to give an odd result. Negative results are to be expected if one chooses to simply:

lump together four years’ worth of recorded utterances, remove all verbal and nonverbal context and grind the result through a computer to look for statistical regularities.

(Gardner and Gardner 1980: 357)

The dispute is still unsettled, and perhaps will remain so, because signing chimps are enormously labour-intensive: every sign has to be observed or video-recorded. So alternative language-systems may be easier to analyse, as will be discussed in the next section.

CONQUERORS OF THE KEYBOARD: LANA AND KANZI

Lana, a female chimp, was the first animal to use a keyboard with visual symbols. She underwent rigorous training in a sophisticated environment – as perhaps befits an animal whose project was partly funded by the Coca-Cola company. Lana’s ‘cage’ at the Yerkes Regional Primate Research Centre in Atlanta, Georgia, was a room of which one side was a huge keyboard linked up to a computer. Beginning in 1971, she was taught to communicate by
pressing the keys, each one of which was marked with a symbol standing for a word. A vending device was attached to the keyboard, so that if Lana correctly requested some item of food or drink, she was able to obtain it immediately (Rumbaugh 1977; Savage-Rumbaugh 1986).

Lana acquired over 100 symbols in her repertoire, which mainly involved items and actions around her, such as ‘give’, ‘banana’, ‘Coke’, and so on. She could cope well with arbitrary symbols, since the symbols on her keyboard were formed by combinations of geometric figures on different coloured backgrounds. For example, a small solid circle inside a larger diamond on a purple background was the symbol for ‘Lana’, the animal’s name. A diamond superimposed on a circle inside a rectangle on a blue background was the symbol for ‘eat’.

Moreover, Lana’s ability to generalize showed that her system had semanticity, that is, she understood that a symbol referred to a certain
type
of object, or colour, not just one particular thing. For example, she was taught the word MORE in connection with an extra ration of fruitjuice. Within a few days, she was reliably attaching the symbol for MORE to other types of food and drink whenever she wanted an additional helping, as in MORE BREAD, MORE MILK. Lana also showed some evidence of creativity. For example, she was taught the words PUT and IN in connection with putting a ball into a bowl or box. Soon after, Tim, one of her trainers, was late with her morning drink of milk. Lana spontaneously made the request TIM PUT MILK IN MACHINE. This shows not only creativity, but also displacement – the ability to talk about absent objects and events. In addition, Lana coined the descriptive phrases APPLE WHICH-IS ORANGE for ‘orange’, and BANANA WHICH-IS GREEN for cucumber.

So far, then, Lana’s language ability seems similar to that of Washoe in that she showed semanticity, displacement and creativity. Let us now look at the way in which she combined symbols. Was she able to cope with structuredependent operations? Clearly, Lana realized that symbols could not be jumbled together randomly. She learned to follow a set sequence in accordance with her trainer’s instructions. She could carry out simple slot-filling exercises, helped by the fact that in her symbol system, each type of word had a different background colour.

It is possible, though unlikely, that she understood the notion of hierarchical structure: the idea that a group of symbols could be substituted for a single one without altering the basic sentence pattern. Her colour-coding system probably hindered her from drawing such conclusions, since in a phrase such as THIS BOWL each word would be a different colour. Furthermore, there is no concrete evidence that she manipulated slots in the way humans do.

To be fair to Lana, however, we perhaps need to consider a conversation which she had with her trainer Tim one Christmas Day. On that day, she produced two similar strings of symbols (Stahlke 1980):

QUERY YOU GIVE COKE TO LANA IN CUP.

QUERY YOU GIVE COKE IN CUP TO LANA.

This looks remarkably like the kind of structure-dependent operation performed by humans, in which they manipulate groups of words to produce different effects. But a closer look at Lana’s behaviour on that Christmas Day suggests that she was not as clever as one might at first suspect. She had begun by demanding Coke, using the first of the sentences listed above: QUERY YOU GIVE COKE TO LANA IN CUP. She repeated this demand seven times, with no success. Then in desperation, and once only, she tried another variant: QUERY YOU GIVE COKE IN CUP TO LANA. It seems, then, that such structural manipulations were not characteristic of Lana’s output, and this one probably occurred by chance. Normally, she adhered rigidly to the sequence she had been taught in order to get her reward, so she had little scope for stylistic modifications. On the basis of this one example, then, it would be premature to conclude that she could cope with structure-dependent operations, which are a crucial characteristic of human language.

Lana’s trainers, incidentally, confidently claim that she had ‘language’, but they define ‘language’ in a much broader way than we have done. To them, a language is any communication system which refers consistently to the outside world by means of a set of arbitrary symbols which are combined together in accordance with conventional rules (Rumbaugh 1977: 66), a definition which might bring even a set of traffic lights within its scope!

Austin and Sherman also deserve a mention. These two young male chimpanzees have been taught the same system as Lana (Savage-Rumbaugh 1986). They have surpassed her in one way, in that they are able to communicate with one another. If Austin presses a symbol for a banana, then Sherman can go into the next room, select the banana from a tray of food, and take it back to Austin. This impressive piece of cooperation does not, however, make the whole system any more language-like.

Let us now move on to Kanzi. Kanzi is a bonobo, a separate ape species, and one discovered only in the twentieth century. Bonobos or ‘pygmy chimps’ are not very different in height from ordinary chimps, but they have longer legs, narrower shoulders, a smaller head and long black hair parted in the middle. Some of their gestures look human-like: they beg by stretching out an open hand, for example. According to some, they are a ‘living link’ between humans and ordinary chimpanzees. Their most noteworthy features are the female-dominated nature of their society, and the high level of sexual activity they indulge in, apparently their preferred method of avoiding conflict. They are also highly intelligent (de Waal 1996, 2006).