Nicaraguan Sign Language (or ISN, Idioma de Señas de Nicaragua) is a sign language developed in isolation from other sign languages in the 1970s in Nicaragua. It was developed when the Sandinista government created a school for deaf children in Nicaragua (there had previously been no such public institution). The language itself was not developed by the government, but evolved naturally from communication among those deaf students.


Following the 1979 Sandinista revolution, the newly installed Nicaraguan Government had hundreds of deaf students enrolled in two Managua schools. Initially, the education officials adopted "finger spelling," using simple signs to limn the alphabets of spoken languages. The result was a complete failure, because most students did not even grasp the concept of words, never having been exposed either to spoken or to written language. The children remained linguistically disconnected from their teachers.

Initially, the students could only use crude gestural signs developed within their own families, but once the students were placed together, they began to build on one another's signs. While the inexperienced teachers found it hard to understand their students, the children had no problem communicating with each other. A new language had begun to bloom. Within just a few generations, a mature language with rules and grammar was born.

The Sandinista officials asked for help from outside scholars. After the linguists finally decoded the children's creation, Nicaraguan Sign Language became a classical case of modern linguistics.

ISN and linguistics

ISN is particularly interesting to linguists because it has apparently grown from a pidgin to a full-fledged creole in a few decades, due to the repeated influx of new child learners who have adopted ISN as their first language.

It also represents the formation of a new language without an adult community of fluent native "speakers", which is otherwise quite unusual. Normal creoles develop from the pidgin mixture of two (or more) distinct communities of fluent speakers, but this pidgin (and later creole) developed from a group of young people with no first language.

Some linguists see what happened in Managua as proof that language acquisition is hard-wired inside the human brain. "The Nicaraguan case is absolutely unique in history," Steven Pinker, author of The Language Instinct, maintains. "We've been able to see how it is that children — not adults — generate language, and we have been able to record it happening in great scientific detail. And it's the first and only time that we've actually seen a language being created out of thin air."


In order to protect the language, some researchers are interested in restricting access of these young ISN users to other forms of sign language (e.g. American Sign Language). Others argue that this is an unethical restriction of their freedom of movement.