The Birth of Nicaraguan Sign Language

A For most of the twentieth century, deaf children in Nicaragua grew up in near-total isolation from one another. Scattered across a poor and largely rural country, they seldom met another deaf person, and there was no shared sign language for them to learn. Within their own families each child improvised a private set of gestures, known to researchers as home sign, to ask for food, name relatives and comment on daily events. These home systems could be surprisingly expressive, but they were invented afresh in every household and could not carry a child beyond the walls of the family home. A deaf child in one village might possess a rich set of signs for the animals, tools and relatives of the household, and yet be quite unable to communicate with a deaf child in the next village, whose gestures were entirely different. Deafness, under such conditions, meant a life of profound isolation.

B This changed abruptly at the end of the 1970s. In 1977 a special school for deaf children opened in the capital, Managua, and a vocational centre followed a few years later. For the first time, hundreds of deaf youngsters were gathered together and travelled to and from the schools on the same buses. In the classroom, teachers concentrated on training the pupils to read lips and to speak Spanish, an approach that produced very little success. Out of the teachers' sight, however, in the playground and on the buses, something remarkable was taking shape as the children pooled their scattered home gestures and began to sign to one another. The buses in particular became unlikely classrooms, for it was there, jolting through the streets of Managua with no adult looking on, that the children had both the freedom and the time to hammer out a common way of communicating.

C The system that first emerged among the oldest pupils was, in the judgement of the linguists who later studied it, more like a pidgin than a full language. It was variable and inconsistent: signs differed from one child to the next, word order was loose, and it lacked the settled grammatical machinery that lets a language express fine distinctions reliably. It was, nevertheless, a genuine shared code, good enough for the first generation of signers to understand one another far better than their old home signs had ever allowed. In this it behaved much as other pidgins do, the rough contact languages that spring up when adults who share no common tongue are thrown together and must somehow trade and talk.

D The decisive transformation came from the youngest children. As new waves of four- and five-year-olds entered the schools, they learned the rough signing of the older pupils but did not simply copy it. Instead they tightened and regularised it, adding consistent word order and grammatical devices that the first generation had never used. Within a few years these young signers were producing something far richer and more systematic than their models had ever managed. The language, now called Idioma de Senas de Nicaragua, had in effect been completed by the children who inherited it rather than by those who began it. Observers were astonished to find that the youngest signers were not merely quicker or more fluent, but were using grammatical devices that simply did not exist in the signing of their older schoolmates.

E News of the schools eventually reached the wider world. In 1986 an American linguist, Judy Kegl, was invited to investigate, and she and her colleagues gradually realised that they were watching something almost never available to science: the birth of a brand-new language, arising with no adult model to copy. Among its most striking features was the use of the space around the signer's body to show which noun a verb referred to, a grammatical trick that the youngest signers used fluently but that the first generation had largely lacked. Kegl and her colleagues had to tread carefully, aware that their very presence might alter the thing they were trying to observe, and much of their work involved patiently recording how children of different ages told the same simple stories.

F For scholars of language the case has been extraordinarily valuable. Because the children were never taught a sign language and had no fully formed one to imitate, their achievement is powerful evidence that the human mind comes equipped with a capacity to create language, and that young children in particular drive the growth of grammatical structure. No researcher could ethically design such an experiment on purpose; only the accident of history, which brought isolated children together at just the right moment, made it possible to observe. For that reason the language of the Managua schools is often described as a natural experiment, a rare gift to science thrown up by circumstance rather than contrived in any laboratory.