Prior to 1977, when a special-education school opened in Managua, Nicaragua had no sign language, official or otherwise. In order to communicate with friends and family, deaf children and adults made do with the hodgepodge system of gestures known as “home-sign.” Each home-sign system was essentially created to meet the needs of an individual and his or her caregivers. And because deaf people interacted with one another so infrequently, these systems naturally differed from each other and were rarely, if ever, transmitted. But when the school’s opening brought a number of deaf children in regular contact with one another, the students—without any assistance from their teachers or administrators—began to create their own common language. Decades later, this language, known as Nicaraguan Sign Language, or Idioma de Señas de Nicaragua (ISL), has more than 800 fluent signers.
So what does a newborn sign language look like? According to a 2004 Science paper published by researchers Ann Senghas, Sotaro Kita, and Asli Özyürek, ISL began as a system of iconic gestures, the sort we might use intuitively to illustrate an event. A complex movement, such as rolling down a hill, was acted out all at once: a single, fluid, downward spiral. In other words, as the researchers point out, “patterns in the representation correspond, part for part, to patterns in the things represented.”
But mature languages, whether spoken or sign, are never this iconic. Instead, they are said to be combinatorial. That is, in place of fixed, holistic representations, full-fledged languages possess a finite set of linguistic units that can be stacked, swapped, and structured like Lincoln Logs.
Eventually, the young signers began to segment their gestures. When researchers compared the signs from an early cohort of students (those who arrived at the school before 1984) to those from later cohorts, they found that the later cohorts were far more likely to break complex actions into components (e.g., produce separate signs for rolling and for down). Over time, the students also converged upon regular syntactic and morphological rules. Where did these rules come from? Certainly not from the Spanish spoken around them. No, they came from the children themselves. Each year, new students enrolled, quickly adopted the emerging system as a native language, and, in doing so, brought increasing sophistication and regularity. As with the artificial language described last week, with each subsequent batch of learners, the language became more of a language.
In constructed languages such as Esperanta, these essential properties spring up fully formed, like Athena from the head of Zeus (or, for some constructed languages, a committee of Zeuses). Natural languages, however, must develop such properties the old-fashioned way, one generation at a time. Thankfully, as Jeff Goldblum might say if he ever played a linguist, languages (and their learners) find a way.
