Nicaragua's Deaf Children Invented Their Own Sign Language When the Government Sent Them to School

Before 1977, deaf children in Nicaragua mostly grew up in isolation, communicating with their families through small home-made gesture systems and rarely meeting another deaf person outside their household. Then the Sandinista revolution and a new education ministry opened a special-education center in Managua's San Judas neighborhood, and 50 deaf children showed up. The teachers tried, and largely failed, to teach lipreading and Spanish. The children started talking to each other in the playground.

What happened next is, as the linguist Steven Pinker has put it, "unique in history" — a complete human language emerging out of nothing, in front of researchers who could record it. By 1983, enrollment had grown past 400 and a second school had opened. The first cohort of children — the older arrivals, who started after their critical period — produced something pidginlike: gesture vocabularies that worked for naming objects and stating events, but with limited grammar. The next cohort, who joined as toddlers and grew up immersed, did something else. They built a full, grammatically structured sign language, including recursive sentence embedding, classifier predicates, and a spatial grammar for distinguishing motion from path.

In June 1986, the MIT-trained linguist Judy Kegl flew to Managua at the request of Nicaragua's education ministry. She decided very early on not to teach the children American Sign Language, on the grounds that it would corrupt whatever the children were doing. What they were doing turned out to be one of the strongest pieces of evidence available for the proposition that the human capacity for language is innate, not learned: given a community and a need to communicate, children will simply build a grammar. The current count of NSL signers is around 3,000.