Humans have the innate inclination towards communication and language. In fact, when deprived of the appropriate language-learning environment, children will develop their own methods of functional communication so long as they are in groups and are not isolated from others with whom they can communicate. This explains the origin of Nicaraguan Sign Language. The deaf children who had previously been isolated from one another in the 1970s were placed in the same vocational school in the beginning of the 1980s where they came together to develop a very complex, well-defined language that follows the same rules as ancient languages that have been passed down through generations. Of course the language didn’t originate with said complexity, but over the years the younger speakers broke down gestures or signs representing larger concepts into their smaller counterparts. You can read more more about how Nicaraguan Sign Language has contributed to the ongoing debate about the influence of “nature” vs. “nurture” on language development, or watch a video illustrating the language’s evolution.
Baby Says More™ would like to clarify that teaching your baby to sign is in no way the same as being a fluent signer of a deaf sign language. Because American Sign Language (ASL) has been marketed for baby sign, which has been labeled ‘baby sign language’ in the past, parents are often under the false impression that their baby “speaks sign language.” On the contrary, having a baby sign repertoire of 10 to 20 signs does not mean that ASL is easy to acquire or that your baby uses sign language. In fact, “the vocabulary of ASL is both opaque and transparent” (Orlansky & Bonvillian, 1984, as cited by Seal, B., 2010), which means that some signs are easier to learn than others. Nonetheless, in general, a sign language, such as ASL, is incredibly difficult to learn at a conversational level.