A Language That Linguists Watched Be Born

The Sandinista government opened the Melania Morales Special Education Center in San Judas, Managua, in 1977, and a vocational school for deaf adolescents in Villa Libertad in 1980. By 1983 there were more than 400 deaf students enrolled — most of whom had grown up in hearing families with only a handful of improvised "home signs" to communicate. The classrooms taught spoken Spanish and lip-reading, with fingerspelling as a crutch. It did not work.

What worked was the schoolyard and the bus. Pooling their idiosyncratic home signs and trading them like vocabulary, the older students hammered out a rough pidgin — what linguists later called Lenguaje de Signos Nicaragüense (LSN). Then the younger children arrived, and something striking happened. They did not just learn the pidgin. They tightened it. They added consistent grammatical aspect, spatial agreement between signs and referents, and verbal classifiers their teachers had never modeled, because their teachers did not sign. By the late 1980s the system the kids were using had a name — Idioma de Señas de Nicaragua, ISN — and a grammar more elaborate than the version their older schoolmates spoke.

Judy Kegl, an MIT-trained linguist, was invited in 1986 and watched the new generation overshoot the older one in real time. The pattern matches what creolists had argued for decades about pidgin-to-creole transitions, except here it was happening on camera, with no other language in the room.

Nicaragua's Cold War-era isolation kept American Sign Language out. That accident is why ISN is, as far as anyone knows, the only language documented from its first generation forward.