Languages are thoroughly organic entities. Each one is complex and versatile, constantly shifting according to the needs of those who use it. When social, political or environmental changes create a gap in a language, its individual speakers use creativity and problem-solving skills to generate a solution. Successful changes to the language are spread quickly and often intuitively.

Another example of creativity influencing language is when small groups of children invent their own languages; however these do not tend to be languages in the fullest sense. They are typically simple, and based on the structures and/or vocabularies of languages that the children already know; they tend to function more as secret codes than anything else.

In at least one case, however, a group of children was able to spontaneously invent a totally new language out of necessity. The children in question were deaf, illiterate, and devoid of all but the most basic language skills, yet they were able to devise an intricate method of communication to use amongst themselves. Nicaraguan Sign Language (or ISN, for either Idioma de Señas de Nicaragua or Idioma de Signos Nicaragüense) is a unique and remarkable linguistic phenomenon of recent years.

After the Sandinista revolution of 1979, Nicaragua opened a school program for deaf children at a special-education center as part of a nationwide campaign to increase literacy. A second school started operating in 1980, and by 1983 the two schools had 400 students between them.

However, progress proved hard to come by. There was no access to any of the hundreds of established sign languages from around the world; instead, the students were instructed in lip-reading and alphabet finger-spelling. Overall, though, the children seemed to retain very little of what they were taught. Because the young students had virtually no language skills, the finger-spelled letters meant nothing to them.

This was unsurprising. Prior to these attempts at teaching them to communicate, deaf children in Nicaragua had interacted with their respective families via idiosyncratic systems of very rudimentary gestures (known as mimicas in Spanish). This meant that deaf children from different families couldn’t even understand each other, let alone form friendships.

But an interesting effect appeared once the many deaf children had begun interacting in the group setting of the schools. The children started learning and elaborating on one another’s mimicas, and the resulting system of signs rapidly grew. The amazed teachers watched as their students began to communicate quite successfully among themselves. This was immeasurably more than any little ‘secret code’ based on an existing, spoken language; these children were inventing the entire structure of ISN along with the vocabulary. They were, in a sense, teaching themselves to use language in general.

When the Nicaraguan Ministry of Education became aware of ISN, its members found themselves baffled by the phenomenon. They asked for help from sign-language specialist Judy Shepard-Kegl, then of Northeastern University in Boston. Intrigued, she set out for Nicaragua to document and analyze the fledgling language. She boldly started out by directly interacting with deaf teenagers at a vocational school. There, she was able to figure out a handful of the more straightforward signs – such as “house” and “what’s up?” – but found herself confounded by the majority of the communication. Frustrated, Kegl moved on to a school for younger children.

The difference between the teenagers’ and the children’s language was striking. The younger speakers of ISN included many more subtleties – for example, verb agreement, in which the number, gender, and/or location of the subject(s) is indicated with verb inflection. It was obvious that the children were using their language at a substantially more fluent level than the teenagers, a finding which coincided with the theorized “critical period” for language acquisition. The idea holds that, in general, young children can rapidly absorb and master new languages until the age of six; the ability declines quickly until age twelve, and after that any acquisition of a new language requires substantially more effort.

In the case of ISN specifically, Kegl suggests that the gestures exchanged by the older students were interpreted by the younger ones as language input. The younger children learned the gestures and very naturally began to add to them, filling in any linguistic gaps encountered along the way. This was what allowed ISN to become a language, rather than a mere set of signs. At this point the older children learned ISN from their younger classmates; their less fluent usage was akin to any second-language acquisition in adulthood. Of course it is still possible that the language could change over time, but it has developed enough that the process would be no different from the gradual shifts of any language.

Kegl and her husband, James Shepard-Kegl, went on to found two experimental schools – the Escuelita de Bluefields and Escuelita de Condega – to teach and observe ISN directly. Teachers at the schools are careful not to introduce any elements of other sign-language systems; these could possibly contaminate the development of ISN. The language now has an estimated 900 to 1200 signers.

The implications of a spontaneously-created language are numerous. Prominent linguists such as Noam Chomsky and Steven Pinker have interpreted ISN’s birth as evidence supporting their respective theories that human beings possess an innate capacity for complex language. Obviously it would be unethical to perform an experiment to see whether a group of children left to grow up completely isolated will develop a language, but the circumstances under which ISN was born were similar.

Late prominent American Sign Language researcher William Stokoe, however, believed that the development of ISN may have been helped along by the children’s limited exposure to Spanish and to other forms of signing. Either way, it is incredible that such an elaborate language was improvised and refined by a group of children who had never truly read or heard a single word. ISN’s origins – along with the fact that it is still thriving after twenty years – stands as a testament to the human mind’s natural ambition to express complex ideas, even in the face of serious obstacles.