The Articulate Mammal (19 page)

Chelsea was another late starter (Curtiss 1988). She is an adult with hearing problems who started learning language in her early thirties. Like Genie, her vocabulary is good, but her syntax is poor. She says things such as: THE WOMAN IS BUS THE GOING, ORANGE TIM CAR IN, BANANA THE EAT. Chelsea’s strange syntax could be due to her late start. But it might also be because of her defective hearing. So neither Genie nor Chelsea provides convincing proof of a ‘cut-off’ point for language acquisition. Each of them has severe non-linguistic problems, which could account for their rudimentary language.

According to Lenneberg, further evidence in favour of a critical period is provided by mentally handicapped children, in particular, Down’s syndrome cases (Lenneberg 1967). These follow the same general path of development as normal children, but much more slowly. Lenneberg claimed that they never catch up because their ability to learn language slows down dramatically at puberty. But some researchers have disputed this claim, arguing that the children’s language ceases to develop through lack of stimulation. Moreover, further work suggests that Down’s syndrome children have a builtin endpoint to their ability. They may reach this ceiling at any age, though often quite a long time before adolescence (Gleitman 1984).

To summarize so far, all the arguments for a sudden onset or final endpoint of the supposed critical period are unconvincing. It may be better to speak of a ‘sensitive period’ – a time early in life when acquiring language is easiest, and which tails off gradually, though never entirely.

Early exposure to language is therefore important. Most of us envy the linguistic ability of young children exposed to two or more languages. They grow up fluent in all of them. Older children hardly ever sound like nativeborn speakers, even when they are talking the same language. Six Canadians
whose families moved to Britain demonstrate this. The youngest, age 7 when he arrived, was eventually almost indistinguishable from his English peers. But those over the age of 14 ‘appear to be heading for life-times with nonnative accents’ (Chambers 1995: 163).

Sign language also shows the need for an early start. Deaf children who have deaf parents start signing earlier, and end up more proficient than deaf youngsters with hearing parents. Nicaragua’s deaf community dramatically demonstrates the advantage of starting young. Here, young deaf signers have developed a partial sign language into a ‘full’ one in under 20 years (Kegl 1994). Before 1980, signing in Nicaragua was minimal, a hotchpotch of different signs. Some 15 or so years later, a whole language had emerged. An outline system learned by the first generation was picked up and elaborated by the next generation. A 7-year-old deaf boy called Santos, for example, learned rudimentary signing from his deaf aunt and uncle. He soon progressed beyond them: ‘His signing was the most fluid and fluent signing I have seen in Nicaragua’ commented one researcher (Senghas 1994: 38), adding that ‘older signers can look to younger children like Santos who lead the way’. These Nicaraguan signers show how fast humans can acquire and even devise a language system for themselves when they are young. Ildefonso, a deaf languageless adult from rural Mexico had far more trouble acquiring signs (Schaller 1995).

But some questions remain. First, is the sensitive period a specifically linguistic one, as Lenneberg suggested, or a more general one? This is unclear, though several neurologists favour the latter: ‘The period between age two and the onset of puberty is one of extreme neural plasticity. There is, however, little … that suggests a specifically linguistic type of mechanism’ is a typical comment (Müller 1996). Further work needs to be done on this.

A second question is this: how does child sensitivity to language work, given how difficult language learning seems to be for most adults? A ‘natural sieve’ hypothesis is one idea. Very young children may be able to extract only certain limited features from what they hear, and may automatically filter out many complexities (Newport 1991). Later learners may have lost this inbuilt filter, and be less able to cope as everything pours over them simultaneously. A ‘tuning-in’ hypothesis is another, overlapping possibility. At each age, a child may be attuned to some particular aspect of language (Locke 1997). Infants may be tuned in to the sounds, older children to the syntax, and after age ten, the vocabulary remains a major concern (Aitchison 1997).

Selective attention of this type fits in well with what we know about biologically programmed behaviour. Children are innately guided to pick out certain features from the sound-stream (or sign-stream), just as bees are instinctively guided to pick out flowers. Some learning is involved for bees, because flowers are so different from one another. But bees end up flying to clover and roses, rather than to postboxes or lamp posts, just as children
acquire language, rather than donkey hee-haws or the twitter of blackbirds (Gould and Marler 1987).

In this chapter, therefore, we have shown that language seems to have the characteristics of biologically programmed behaviour. It emerges before it is necessary, and its emergence cannot be accounted for either by an external event, or by a sudden decision taken by the child. Direct teaching and intensive practice have relatively little effect. Acquisition follows a regular sequence of milestones which can be loosely correlated with other aspects of the child’s development. In other words, there is an internal mechanism both to trigger it off and to regulate it. There is a sensitive period for acquiring it, with early exposure a strong advantage, since younger brains have more plasticity.

However, it would be wrong to think of language as something which is governed
only
by internal mechanisms. These mechanisms require external stimulation in order to work properly. The child needs a rich verbal environment during the acquisition period.

This suggests that the so-called nature–nurture controversy mentioned in
Chapter 1
may be misconceived. Both sides are right: nature triggers off the behaviour, and lays down the framework, but careful nurture is needed for it to reach its full potential. The dividing line between ‘natural’ and ‘nurtured’ behaviour is by no means as clear cut as was once thought. In other words, language is ‘natural’ behaviour – but it still has to be carefully ‘nurtured’ in order to reach its full potential. In modern terminology, the behaviour is
innately guided.
Or, as another writer expressed it in the title of his book, we should be talking about
Nature via Nurture
(Ridley 2003).

But, although we have now shed considerable light on the general problem of innateness, and the difficulty of separating natural from nurtured behaviour, we have not yet tried to answer the crucial question, exactly what, if anything, could be innate? We noted in
Chapter 1
that Chomsky argued in favour of postulating a ‘rich internal structure’. What in his opinion does this structure consist of? And what do Chomsky’s opponents say? This is the topic considered in the next chapter.

5

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A BLUEPRINT IN THE BRAIN?

Could any linguistic information conceivably be innate?

There are very deep and restrictive principles that determine the nature of human language and are rooted in the specific character of the human mind.

Chomsky,
Language and Mind

Young children must learn … the set of linguistic conventions used by those around them … for any given language … The human species is biologically prepared for this prodigious task …, but this preparation cannot be too specific, as human children must be flexible enough to learn not only all of the different words and conventional expressions of any language but also all the different types of abstract constructional patterns … It thus takes many years.

Tomasello,
Constructing a Language

It is relatively easy to show that humans are innately predisposed to acquire language. The hard part is finding out exactly
what
is innate. People have indulged in speculation about this for centuries. Over two thousand years ago the Egyptian king Psammetichus had a theory that if a child was isolated from human speech, the first word he spontaneously uttered would come from the world’s oldest inhabitants. Naturally he hoped this would be Egyptian. He gave instructions for two newborn children to be brought up in total isolation. When eventually the children uttered the word BEKOS, Psammetichus discovered to his dismay that this was the Phrygian word for ‘bread’. He
reluctantly concluded that the Phrygians were more ancient than the Egyptians.

Nobody takes Psammetichus’s theory seriously today – especially as the few reliable accounts we have of children brought up without human contact indicate that they were totally without speech when they were found. The famous French boy, Victor of Aveyron, who was discovered naked rooting for acorns in the Caune woods in 1797, did not speak Phrygian or any other language. He merely grunted like an animal.

Although the speculations of Psammetichus can safely be ignored, the ideas of Noam Chomsky on the topic of innateness were for a long time taken seriously. He claimed that for language acquisition to be possible, a child must be endowed with a ‘rich internal structure’, and the biological evidence examined in the last two chapters suggest that his ideas cannot be summarily dismissed. Chomsky’s notion of a rich innate schema contrasted strongly with the point of view popularly held earlier in the century that children are born with ‘blank sheets’ as far as language is concerned. Consequently, some people considered Chomsky as someone who had set out to shock the world with outrageous and novel proposals. But Chomsky denied this. He pointed out that he was following in the footsteps of eighteenth-century ‘rationalist’ philosophers, who believed in the existence of ‘innate ideas’. Such philosophers held that ‘beyond the peripheral processing mechanisms, there are innate ideas and principles of various kinds that determine the form of the acquired knowledge in what may be a rather restricted and highly organized way’ (Chomsky 1965: 48). Descartes, for example, suggested that when a child sees a triangle, the imperfect triangle before his eyes immediately reminds him of a true triangle, since we already possess within us the idea of a true triangle.

But leaving philosophical predecessors aside, what exactly does (or did) Chomsky regard as innate? In his words: ‘What are the initial assumptions concerning the nature of language that the child brings to language learning, and how detailed and specific is the innate scheme?’ (Chomsky 1965: 27).

Chomsky gave an explicit account of his early views in his (now outdated) linguistic classic
Aspects of the Theory of Syntax
(1965), though he has repeated them in a number of other places with minor variations. But in recent years he has changed his mind on various points, sometimes quite fundamentally. His later views were set out in
Knowledge of Language: Its Nature, Origin and Use
(1986), later ones still in
The Minimalist Program
(1995) and further views in
On Nature and Language
(2002). The following account begins with his 1965 statements. It then explains why he came to regard these as unsatisfactory, and outlines his more recent ideas. It then discusses why Chomsky’s ideas are gradually fading from the forefront of research, and those of later scholars, such as Michael Tomasello, are taking over.

CHOMSKY’S EARLY IDEAS: LAD AND LAS

Chomsky has never regarded his proposals on the matter of innateness as definitive: ‘For the present we cannot come at all close to making a hypothesis that is rich, detailed and specific enough to account for the fact of language acquisition’ (1965: 27). Nevertheless, his ideas were specific enough to be interesting.

Chomsky started out with the basic assumption that anybody who acquires a language is not just learning an accumulation of random utterances but a set of ‘rules’ or underlying principles for forming speech patterns: ‘The person who has acquired knowledge of a language has internalized a system of rules that relate sound and meaning in a particular way’ (Chomsky 1972b: 26). These ‘rules’ enable a speaker to produce an indefinite number of novel utterances, rather than straight repetitions of old ones. As we saw in
Chapters 1
and
2
, an essential characteristic of language is its creativity. People do not just run through a repertoire of stereotyped phrases when they speak. Instead, they are continually producing novel utterances such as ‘My baby swallowed four ladybirds’, or ‘Serendipity upsets me’. But where do the rules come from? How do speakers discover them? Somehow, children have to construct their own set of rules from the jumble of speech they hear going on around them. This is a formidable task. Chomsky pointed out that children are to some extent in the same situation as a linguist faced with an unknown language. Both child and linguist are surrounded by a superficially unintelligible confusion of sound which they must somehow sort out.

So let us first consider how a
linguist
deals with this unknown language situation. She possibly starts by finding simple sound sequences which refer to single objects, such as TREE, NOSE, CONGER EEL. But this stage is not particularly interesting from a syntactic point of view. Learning a few dozen vocabulary items is a relatively simple task, as is clear from the ease with which the chimp Washoe managed to do this. In addition, Genie, the Californian teenager discussed in
Chapter 4
, found the acquisition of vocabulary easy – it was the grammatical rules that slowed her down. For a linguist working on an exotic language, the interesting stage is likely to come when she starts to notice recurring syntactic patterns among the data. As soon as she has found some, she begins to make guesses or
hypotheses
concerning the principles which underlie the patterns. For example, suppose she repeatedly finds the utterances WOKKI SNIZZIT, WOKKI UGGIT and WOKKI SNIFFIT. She might hazard, as a first guess that the sequence WOKKI always has to be followed by a sequence which ends in -IT. But if, later, she finds utterances such as LUKKIT WOKKI and UKKING WOKKI, she would have to abandon her original, oversimple theory, and form a new, more complex hypothesis to account for the
fresh data. She continues this process of forming hypotheses, testing them, then abandoning them when they prove inadequate until, ideally, she has compiled a set of rules which can account for all the possible sequences of the language she is studying.