Monday, June 13, 2016

Vyvyan Evans - Chomsky's idea of a language instinct is simple, powerful and completely wrong

For decades, the idea of a language instinct has dominated linguistics. It is simple, powerful and completely wrong

NB: There have been several critical reactions to this piece, links to which are at the bottom of this post - DS

Imagine you’re a traveller in a strange land. A local approaches you and starts jabbering away in an unfamiliar language. He seems earnest, and is pointing off somewhere. But you can’t decipher the words, no matter how hard you try.

That’s pretty much the position of a young child when she first encounters language. In fact, she would seem to be in an even more challenging position. Not only is her world full of ceaseless gobbledygook; unlike our hypothetical traveller, she isn’t even aware that these people are attempting to communicate. And yet, by the age of four, every cognitively normal child on the planet has been transformed into a linguistic genius: this before formal schooling, before they can ride bicycles, tie their own shoelaces or do rudimentary addition and subtraction. It seems like a miracle. The task of explaining this miracle has been, arguably, the central concern of the scientific study of language for more than 50 years.

In the 1960s, the US linguist and philosopher Noam Chomsky offered what looked like a solution. He argued that children don’t in fact learn their mother tongue – or at least, not right down to the grammatical building blocks (the whole process was far too quick and painless for that). He concluded that they must be born with a rudimentary body of grammatical knowledge – a ‘Universal Grammar’ – written into the human DNA. With this hard-wired predisposition for language, it should be a relatively trivial matter to pick up the superficial differences between, say, English and French. The process works because infants have an instinct for language: a grammatical toolkit that works on all languages the world over.

At a stroke, this device removes the pain of learning one’s mother tongue, and explains how a child can pick up a native language in such a short time. It’s brilliant. Chomsky’s idea dominated the science of language for four decades. And yet it turns out to be a myth. A welter of new evidence has emerged over the past few years, demonstrating that Chomsky is plain wrong.

But let’s back up a little. There’s one point that everyone agrees upon: our species exhibits a clear biological preparedness for language. Our brains really are ‘language-ready’ in the following limited sense: they have the right sort of working memory to process sentence-level syntax, and an unusually large prefrontal cortex that gives us the associative learning capacity to use symbols in the first place. 

Then again, our bodies are language-ready too: our larynx is set low relative to that of other hominid species, letting us expel and control the passage of air. And the position of the tiny hyoid bone in our jaws gives us fine muscular control over our mouths and tongues, enabling us to make as many as the 144 distinct speech sounds heard in some languages. No one denies that these things are thoroughly innate, or that they are important to language.

What is in dispute is the claim that knowledge of language itself – the language software – is something that each human child is born with. Chomsky’s idea is this: just as we grow distinctive human organs – hearts, brains, kidneys and livers – so we grow language in the mind, which Chomsky likens to a ‘language organ’. This organ begins to emerge early in infancy. It contains a blueprint for all the possible sets of grammar rules in all the world’s languages. And so it is child’s play to pick up any naturally occurring human language. A child born in Tokyo learns to speak Japanese while one born in London picks up English, and on the surface these languages look very different. But underneath, they are essentially the same, running on a common grammatical operating system. The Canadian cognitive scientist Steven Pinker has dubbed this capacity our ‘language instinct’.

There are two basic arguments for the existence of this language instinct. The first is the problem of poor teachers. As Chomsky pointed out in 1965, children seem to pick up their mother tongue without much explicit instruction. When they say: ‘Daddy, look at the sheeps,’ or ‘Mummy crossed [ie, is cross with] me,’ their parents don’t correct their mangled grammar, they just marvel at how cute they are. Furthermore, such seemingly elementary errors conceal amazing grammatical accomplishments. Somehow, the child understands that there is a lexical class – nouns – that can be singular or plural, and that this distinction doesn’t apply to other lexical classes.

This sort of knowledge is not explicitly taught; most parents don’t have any explicit grammar training themselves. And it’s hard to see how children could work out the rules just by listening closely: it seems fundamental to grasping how a language works. To know that there are nouns, which can be pluralised, and which are distinct from, say, verbs, is where the idea of a language instinct really earns its keep. Children don’t have to figure out everything from scratch: certain basic distinctions come for free.

Chomsky’s second argument shifts the focus to the abilities of the child. Think of this one as the problem of poor students. What general-purpose learning capabilities do children bring to the process of language acquisition? When Chomsky was formulating his ideas, the most influential theories of learning – for instance, the behaviourist approach of the US psychologist B F Skinner – seemed woefully unequal to the challenge that language presented.

Behaviourism saw all learning as a matter of stimulus-response reinforcement, in much the same way that Pavlov’s dog could be trained to salivate on hearing a dinner bell. But as Chomsky pointed out, in a devastating 1959 review of Skinner’s claims, the fact that children don’t receive formal instruction in their mother tongue means that behaviourism can’t explain how they acquire competence in grammar. Chomsky concluded that children must come to the language-learning process already prepared in some way. If they are not explicitly taught how grammar works, and their native learning abilities are not up to the task of learning by observation alone, then, by process of elimination, their grammar smarts must be present at birth.

Those, more or less, are the arguments that have sustained Chomsky’s project ever since. They seem fairly modest, don’t they? And yet the theoretical baggage that they impose on the basic idea turns out to be extremely significant. Over the past two decades, the language instinct has staggered under the weight.

Let’s start with a fairly basic point. How much sense does it make to call whatever inborn basis for language we might have an ‘instinct’?.. read more

Critical reactions to Evans from scholars of linguistics and cognitive science. (Chomsky has not been known to use the phrase 'language instinct' - that phrase, misleading as it is, is from the work of Steven Pinker).
-(David Pesetsky is head of department of linguistics and philosophy at MIT: The reason many linguists are so upset by Evans' book, to which they were alerted by Hornstein's columns, has little to do with scientific disagreements or dueling world views. What has us appalled is the crude and blatant falsification of opposing views that pervades the book and its summary in Aeon that brought it to our attention — and the fact that a major scholarly press agreed to publish such a thing.)