Minding our language
the American linguist and social critic Noam Chomsky once asserted that human beings, apart from being the only species able to communicate through a spoken language, are further endowed at birth with an innate linguistic ability.
What Chomsky meant is that the human brain is essentially precon-ditioned to construct the components and interrelationships that characterise the numerous languages and dialects. He was led to formulate this hypothesis after discovering that all human languages shared certain common structural features which he called "universal grammar".
A recent finding by Susan Goldin-Meadow and Carolyn Mylander of the University of Chicago (Nature, Vol 391, No 6664) offers strong support to the Chomskian viewpoint. These two psychologists used the known fact that deaf children, deprived of a normal linguistic input, nevertheless learn to communicate with the help of a system of signs and gestures that they often invent for themselves. These signs and gestures can be broken down into words and sentences just as in normal language. However, the question is: do these gestural systems also contain grammatical features of ordinary spoken language, thereby strengthening the case for innateness?
The answer, as the duo found out, was yes, and in quite an astonishing manner at that. The psychologists made video recordings of communication within two groups of four infants, both around four years of age. One group lived in Taiwan and the other in the us. All the children were congenitally deaf and were being taught to lip-read and also the rudiments of speech, but none had been exposed to a conventional sign system. However, the team found several striking features of the sign language that the two groups had invented quite independently.
Firstly, communication (the video recordings were mainly of exchanges with their mothers) was encoded by means of gestural sentences rather than single gestures. Secondly, the grouping of the "words" in a sentence resembled a pattern common to many spoken languages, though neither to English or Mandarin, which were their respective mother tongues. This pattern linguistically distinguished between the subject of a transitive sentence; for instance, "Mouse" in "Mouse eats cheese" from the subject of an intransitive sentence for example, "Mouse" in "Mouse goes to hole". Thirdly, the children from both cultures produced gestures in a similar order: for instance, intransitive actors always preceded the acts themselves just as "Mouse" invariably preceded "goes", which was not necessarily true of the pair "Mouse" and "eats". Finally, all the infants were able to produce complex sentences by fusing elements; for example, to signal something as complex to the mother as the instruction "Twist the jar open, then blow a bubble and I will clap". This property, known as generative capability, is a hallmark of all natural languages.
In a curious footnote, Goldin-Meadow and Mylander noted that Chinese mothers learnt from their children and ordered their gestures in the same manner that their infants did, whereas the American mothers did not, but used seemingly random patterns instead. Mothers produced fewer complex sentences than their children in both cultures.
The structural similarities in the gestural patterns developed independently by two groups of children from such different cultures can be interpreted in only one way - by inferring that the capacity to generate at least some linguistic structures must indeed be an innate characteristic of the human brain.