The Articulate Mammal (9 page)

(Lewis Carroll)

A final, crucial feature of language has come to the forefront in recent years. This is
intention-reading
(Tomasello 2003), or
mind-reading
(Baron-Cohen 1999). Normal humans are able to understand the intentions of other humans. If one saw a child shivering, one might realize it was cold, and try to lend it a warm jersey. This ability to empathize with another, to put oneself into another person’s shoes, as it were, may be the key to language, and is not found fully in the (non-human) animal world. Some limited awareness of it has been detected among apes, especially chimps. But humans are the best at this skill: ‘Human beings are the world’s experts at mind reading. As compared with other species, humans are much more skillful at discerning what others are perceiving, intending, desiring, knowing, and believing. Although the pinnacle of mind-reading is understanding beliefs – as beliefs are indisputably mental and normative – the foundational skill is understanding intentions.’ (Tomasello
et al.
2005).

Animal researchers have suggested that mind-reading is revealed by an ability to deceive one another (Byrne and Whiten 1992; Aitchison 1996/2000), since true deceit requires one to think about another person’s mind-set. An infant chimp was observed to scream in order to persuade its mother to comfort it. An older chimp led other chimps away from a hidden store of bananas, then doubled back in order to scoff his bananas alone. The possible brain adaptations which underlie mind-reading will be discussed in
Chapter 3
, though a basic problem is that intention reading is not an all or nothing skill, it can be partial both in some humans (usually very young or sometimes mentally handicapped people) and perhaps in some apes.

It is now possible to answer the question, can animals talk? If, in order to qualify as ‘talkers’ they have to utilize all the design characteristics of human language ‘naturally’, the answer is clearly ‘no’. Some animals possess some of the features. Birdsong has duality, and bee dancing has some degree of displacement. But, as far as we know, no animal communication system has duality
and
displacement. No animal system can be proved to have semanticity or to use structure-dependent operations. Above all, no animal can communicate creatively with another animal, and no animal can mind-read with the ease and efficiency of humans.

But although animals do not ‘naturally’ talk, this does not mean that they are
incapable
of talking. Perhaps they have just never had the chance to learn language. The next section examines the results obtained with animals which have had this opportunity.

In discussing attempts to teach language to animals, mimicry must be distinguished from ‘true’ language. Mynah birds can imitate humans with uncanny accuracy, but like most talking birds, they are merely ‘parroting’ back what they hear. A budgerigar I knew heard a puppy being trained with words such as ‘Sit!’ ‘Naughty boy!’ and used to shriek ‘Sit!’ ‘Naughty boy!’ whenever anyone went near its cage, whether or not the dog was present.

Yet some parrots might be capable of more. Nearly half a century ago, a grey parrot could apparently say ‘Good morning’ and ‘Good evening’ at the right times, and ‘Goodbye’ when guests left (Brown 1958). More recently, Alex, another grey parrot, has gone much further. Alex was bought from a pet store in the Chicago area of America in 1977 when he was 13 months old. After careful training, he could label more than thirty objects, such as grape, chair, key, carrot; seven colours such as blue, yellow, purple; and five shapes such as triangle, square. He could also respond to questions asking whether colours and shapes were the same or different (Pepperberg 2000). This is far more than ‘bird-brains’ were assumed to be capable of. But even Alex’s achievements are low compared with those of apes, as will be outlined below.

TEACHING SIGN LANGUAGE TO APES: WASHOE AND NIM

Over the past 50 or so years, several attempts have been made to teach human language to chimpanzees. The first experiment was a failure. An animal named Gua was acquired by Luella and Winthrop Kellogg in 1931, when she was 7 months old (Brown 1958; Kellogg and Kellogg 1933). She was brought up as if she was a human baby, and was fed with a spoon, bathed, pinned up in nappies, and continuously exposed to speech. Although she eventually managed to understand the meaning of over seventy single words, she never spoke. Gua showed clearly that it was
not
just lack of opportunity which prevents a chimp from learning language. The Kelloggs’ son Donald, who was
brought up alongside Gua, and was approximately the same age, grew up speaking normally.

A second chimp acquired by Keith and Cathy Hayes in 1947 also proved disappointing (Brown 1958; Hayes 1951). Viki was given intensive coaching in English. She eventually learnt four words: PAPA, MAMA, CUP, UP. But these were very unclearly articulated, and remained the sum total of Viki’s utterances after three years of hard training.

It is now clear why these attempts failed. Chimps are not physiologically capable of uttering human sounds. More recent experiments have avoided this trap and used other media. Let us consider some of this later research.

From the mid 1960s, teaching language to apes became a popular pastime among American psychologists. A minor population explosion of ‘talking chimps’ followed. Broadly, they can be divided into signers, who were taught sign language, and pointers, who pressed symbols on a keyboard. Our discussion will begin with two signers, Washoe and Nim, then move on to two pointers, Lana and Kanzi.

Washoe’s exact age is unknown, but she is estimated to now be over 40 years old. She is a female chimp acquired by Allen and Beatrix Gardner in 1966, when she was thought to be approximately a year old. She was taught to use modified American sign language (ASL). In this system signs stand for words. For example, Washoe’s word for ‘sweet’ was made by putting her finger on the top of her tongue, while wagging the tongue. Her word for ‘funny’ was signalled by pressing the tip of her finger on to her nose, and uttering a snort.

Washoe acquired her language in a fairly ‘natural’ way. The Gardners kept her continuously surrounded by humans who communicated with her and each other by signs. They hoped that some of this would ‘rub off’ on her. Sometimes they asked her to imitate them, or tried to correct her. But there were no rigorous training schedules.

Even so, teaching a wild chimpanzee was quite a problem: ‘Washoe can become completely diverted from her original object, she may ask for something entirely different, run away, go into a tantrum, or even bite her tutor’ (Gardner and Gardner 1969: 666). But her progress was impressive and, at least in the early stages, her language development was not unlike that of a human child.

First, she acquired a number of single words, for example COME, GIMME, HURRY, SWEET, TICKLE – which amounted to thirty-four after 21 months, but later crept up to well over one hundred. The number is accurate because a rota of students and researchers made sure that Washoe, who lived in a caravan in the Gardners’ garden, was never alone when she was awake. And a sign was assumed to be acquired only after Washoe had used it spontaneously and appropriately on consecutive days.

Washoe’s speech clearly had ‘semanticity’. She had no difficulty in understanding that a sign ‘meant’ a certain object or action, as was shown by her acquisition of the word for ‘toothbrush’ (index finger rubbed against teeth). She was forced, at first against her will, to have her teeth brushed after every meal. Consequently, she had seen the sign for ‘toothbrush’ on numerous occasions, though she had never used it herself. One day, when she was visiting the Gardners’ home she found a mug of toothbrushes in the bathroom. Spontaneously, she made the sign for ‘toothbrush’. She was not asking for a toothbrush, as they were within reach. Nor was she asking to have her teeth brushed, a procedure she hated. She appeared simply to be ‘naming’ the object. Similarly, Washoe made the sign for ‘flower’ (holding the fingertips of one hand together and touching the nostrils with them) when she was walking towards a flower garden, and another time when she was shown a picture of flowers.

Washoe could also generalize from one situation to another, as was clear from her use of the sign meaning ‘more’. Like all chimps, she loved being tickled, and she would pester any companion to continue tickling her by using the ‘more’ sign. At first the sign was specific to the tickling situation. Later she used it to request continuation of another favourite activity, being pushed across the floor in a laundry basket. Eventually, she extended the ‘more’ sign to feeding and other activities. Similarly, the word for ‘key’ referred originally only to the key used to unlock the doors and cupboards in her caravan. Later, she used the sign spontaneously to refer to a wide variety of keys, including car ignition keys. Her ‘speech’ also incorporated a limited amount of displacement, since she could ask for absent objects and people.

But most impressive of all was Washoe’s creativity – her apparently spontaneous use of combinations of signs. She produced two- and three-word sequences of her own invention, such as GIMME TICKLE ‘Come and tickle me’, GO SWEET ‘Take me to the raspberry bushes’, OPEN FOOD DRINK ‘Open the fridge’, LISTEN EAT ‘Listen to the dinner gong’, HURRY GIMME TOOTHBRUSH, and ROGER WASHOE TICKLE. Washoe’s signs were not just accidental juxtapositions. During a sequence of signs Washoe kept her hands up in the ‘signing area’. After each sequence she let them drop. This is comparable to the use of intonation by humans to signal that words are meant to be joined together in a construction. Does this mean that Washoe could actually ‘talk’? At least superficially, her sequences seem parallel to the utterances of a human child. Washoe’s requests for MORE SWEET, MORE TICKLE seem similar to requests for MORE MILK or MORE SWING recorded from children. But there is one important difference. Children normally preserve a fixed word order. English children put the subject or agent of a sentence before the action word, as in MUMMY COME, EVE READ, ADAM PUT, CAR GONE. But Washoe did not always seem to care in what order she gave her signs. She was as likely to say SWEET GO as GO SWEET to mean ‘Take me to the raspberry bushes’.

There are a number of possible explanations. First, the overeagerness of the researchers who worked with Washoe may have been to blame. They were so anxious to encourage her that they rushed to gratify every whim. Since SWEET GO and GO SWEET have only one possible interpretation – Washoe wanted some raspberries – they immediately understood and took her there. The idea that word ordering was necessary may never have occurred to her. Perhaps if she had ever experienced difficulty in making herself understood she might have been more careful about structuring her sequences.

Another possibility is that it may be easier to utter vocal sounds in sequence than it is to maintain a fixed order with signs. Some studies have suggested that deaf adults are inconsistent in their ordering of sign language.

A third possibility is that the fluctuating order in Washoe’s signing was merely a temporary intermediate stage which occurred before Washoe eventually learnt to keep to a fixed sequence. This is the point of view supported by the Gardners. They claim that Washoe eventually settled down to a standard sign order which was based on the order of adult English (since, of course, Washoe’s companions had used an English word order when they used sign language with her).

Yet another possible explanation of Washoe’s unreliable sign order is that she did not, and could not, understand the essentially patterned nature of language. In this case, she certainly did not understand or use structuredependent operations, one of the key tests for determining whether she can ‘talk’. But it is difficult to be sure. And we may never know for certain as she is no longer in the situation where she is continually surrounded by humans whose main task is to hold conversations with her. She grew so large and potentially dangerous that the Gardners were obliged to send her to live at a primate sanctuary. But even when her period of intensive exposure to sign language was over, research assistants still came to talk to her (Fouts 1997). After leaving the Gardners, she continued to use signs creatively, as when she spontaneously signed WATERBIRD to mean ‘swan’. However, since she was beside a river when she produced this combination, it is possible that she made two separate signs, one referring to the water, the other to the swan.

In her new home, Washoe was given an infant chimp, Loulis, to adopt, and tried to teach him some signs. On one occasion, Washoe put a chair in front of Loulis, and then demonstrated the CHAIRSIT sign to him five times. And, both through imitating Washoe and other signing chimps, Loulis developed his own repertoire of signs (Fouts
et al
1982; Fouts 1983). These days, Washoe, Loulis and two other chimps, Tatu and Dar all live together. They interact with humans and each other by means of signs, though of course also use spontaneous chimp gestures and vocalizations.

Now the fact that Washoe spontaneously transmitted signs to another chimp is interesting and important, but it does not magically turn these signs
into ‘language’. In brief, we have to conclude that although Washoe’s speech is sometimes creative, and showed semanticity and displacement, it has not been shown to be structure-dependent. We cannot be sure, because Washoe’s ‘speech’ was only ever partly analysed – recording it all was impossible, and any repeated signs were usually ignored by the Gardners.

But Nim Chimpsky, a male chimpanzee, who was taught a sign system some years later, was attended by a fleet of graduate students who recorded his every sign. He was for several years under the care of Herbert Terrace at Columbia University, New York. Somewhat ironically, Nim’s achievements began to interest psycholinguists mainly after the project ran out of money, and Nim was returned to a chimpanzee colony in Oklahoma. Without Nim around, Terrace found that he had much more time to analyse the material he had collected so far. The data from Project Nim, therefore, have been examined much more carefully than those from any of the other animals. With Nim out of the way, Herbert Terrace was able to sort out and classify the data he had accumulated over the previous 4 years.