Linguistics has a name for the study it is never allowed to run: the forbidden experiment. Cut children off from all language, the grim thought experiment goes, and see what their minds build in its place. No ethics board on Earth would approve it. Yet in the schoolyards of Managua in the early 1980s, history ran a benign version of it by accident — and a group of deaf Nicaraguan children became the only people in modern times known to have built a brand-new language from nothing, while linguists watched.
Before the late 1970s, Nicaragua had no deaf community to speak of. There were no schools for deaf children, no shared sign language, and no easy way for deaf people to find one another. Most deaf children grew up at home among hearing relatives, communicating through 'home signs' — improvised gestures for eat, drink, come, go — that differed from household to household. Two deaf strangers meeting in the street had no common language at all. Then, in 1977, a centre for special education opened in Managua with a few dozen deaf pupils. After the Sandinista revolution of 1979, enrolment swelled into the hundreds, and a vocational school for deaf adolescents followed in 1981. For the first time in the country's history, deaf children were together in numbers.
The teaching itself was a failure. Following the fashion of the era, staff drilled the children in lip-reading and spoken Spanish, with dismal results; few pupils ever learned to hold a conversation that way. But the school's real work was happening where nobody was teaching anything — in the playground, the corridors and the school buses. The children pooled their home signs, and out of the jumble a rough common system emerged: a pidgin, functional but ragged, varying widely from signer to signer. The teachers could not understand it, and the ministry, fearing the whole programme had failed, asked for outside help.
The children who out-signed their elders
In 1986 the American linguist Judy Kegl arrived at the ministry's invitation, and found something no linguist had ever documented. The older teenagers signed the ragged pidgin. But the youngest children — those who had arrived small, into a signing community that already existed — were doing something else entirely: signing faster, more fluently and more consistently, with the beginnings of real grammar. The children had not learned a language; the youngest of them were building one. Researchers came to distinguish the older group's pidgin from the young children's creation, Idioma de Señas de Nicaragua — Nicaraguan Sign Language — a full language with rules of its own.
The most elegant demonstration came from the linguist Ann Senghas, who studied successive 'cohorts' of signers. She showed them a cartoon in which a cat swallows a bowling ball and wobbles at speed down a steep street, then asked them to sign what happened. Older, first-cohort signers produced a single holistic gesture — a hand rolling and descending at once, much as anyone might mime it. Younger signers instead broke the event into separate signs — rolling, then descending — strung together in sequence. That is the signature of true language: a small set of discrete units that can be endlessly recombined, rather than one-off pantomime. The younger cohorts also developed a grammatical use of space, directing verbs towards locations to mark who did what to whom.
What a new language proves
The implications reach far beyond Nicaragua. Because the language owes nothing to Spanish and nothing to American Sign Language — it is not a gestured version of anything — it offers rare evidence that children do not merely absorb language but actively construct it, imposing grammar on inconsistent input. The pattern fits what the linguist Derek Bickerton observed in spoken creoles, where the children of pidgin-speaking parents produce a fully grammatical language within a generation, and it became a favourite exhibit in arguments, associated with Noam Chomsky and popularised by Steven Pinker, that the capacity for grammar is part of our biological endowment. It also gave striking support to the idea of a critical period: the children who entered the community youngest became the most fluent signers, while those who arrived in their late teens never caught up, remaining pidgin signers for life.
Nicaraguan Sign Language is not quite unique — a comparable case, Al-Sayyid Bedouin Sign Language, arose over several generations in a Negev desert village with widespread hereditary deafness — but nowhere else did scientists arrive early enough to track a language's birth cohort by cohort. Today the language has thousands of users, an established deaf community centred on Managua, and formal recognition from the Nicaraguan state. The children who made it are middle-aged now: native speakers of a language younger than they are.
No committee designed it, no academy polished it, and no adult could have produced it. Handed the fragments of a hundred private gesture systems, the youngest children in a Managua schoolyard quietly did what human children appear built to do — they turned noise into grammar, and gave linguistics the closest thing it will ever have to watching a language being born.
Quiz nuggets
- Nicaraguan Sign Language emerged among deaf children after a special-education centre opened in Managua in 1977 and expanded following the 1979 Sandinista revolution.
- The American linguist Judy Kegl, invited by Nicaragua's education ministry, began studying the new language in 1986.
- Linguist Ann Senghas used a cartoon of a cat swallowing a bowling ball to show younger signers breaking events into discrete, recombinable signs.
- Nicaraguan Sign Language is unrelated to both Spanish and American Sign Language.
- Al-Sayyid Bedouin Sign Language, from a Negev desert village with hereditary deafness, is another documented case of a sign language arising spontaneously.