When the Deaf Child Babbles
A baby practicing manual babbling by reaching out and gesturing with their hand, illustrating the early stages of sign language development.
What were the first sounds your baby made? Goo goo, ga ga, dadada, or maybe mamamama? Parents hang on every sound and movement, ready to run a victory lap. What do these sounds really mean? At one time, it was believed that they held no meaning. They simply represented the maturing of the vocal cords, throat, tongue, etc. This is a bit of an oversimplification and not wholly accurate (Petitto and Marentette 1991).
More recent research suggests these sounds are akin to building blocks to language. Think of them as bricks or even the components of bricks, such as bits of sand and clay (I promise, I looked this up). The sounds themselves are just components that will be later joined together to make words (bricks), and those words will become sentences (walls) and will deepen in their meaning and execution (houses).
These language pieces or units are copied based on their exposure to the spoken word as family speaks to them or to each other. What about profoundly deaf children? They don’t have access to this spoken language. Do they produce the same linguistic units? Yes and no.
Petitto, Laura Ann and Paula F. Marentette established in their 1991 study that language does not necessarily originate in the mouth, throat, lungs, or, in the case of the Deaf child, the hands. It originates in the brain. The brain is where we first process language and begin to understand and then reciprocate and express the language.
As I mentioned, the profoundly Deaf child does not have access to spoken language, so what language is there to process? This is where it gets interesting. In this study deaf children of deaf parents did as their hearing counterparts and produced the units of the language to which they were exposed: sign language (Petitto and Marentette 1991). It's important to note here that although this study was relatively small, it set the stage for other later, and larger studies that confirmed these findings.
The Deaf children would produce the units. They produced movements, shapes, and positioning relative to the body that would later be used to form whole signs (Petitto and Marentette 1991). Deaf babies babbled! This was compared to the hand movements of the hearing children. The deaf children had far more distinct hand movements and markers that were later used to form signs than what was seen in the hearing children. This wasn’t the usual pointing at things because they want something or reaching for a parent to be picked up. These movements were excluded and not counted as the language parts (Petitto and Marentette 1991). This leads to other questions that I will discuss in later articles.
For example:
What about hearing children of deaf parents who rely on signed language?
What about deaf children of hearing parents that do not sign?
Are hearing children that learn sign language early in life hindered in their development of spoken language?
Some of these questions can be branched off into other topics that will let me touch on language deprivation of deaf children, the value of signed language for nonverbal children, and much more.
This article mostly focused on,
Petitto, Laura Ann and Paula F. Marentette. 1991. "Babbling in the Manual Mode: Evidence for the Ontogeny of Language." Science 251(5000):1493+.
Other articles that support the same conclusions and are interesting reads,
Petitto, Laura Ann, Darlene Holowka, Laraine E. Sergio, and David Ostry. 2004. "Baby Hands that Move to the Rhythm of Language: Hearing Babies Acquiring Sign Languages Babble Silently on the Hands." Cognition 93(1):43–73.
Meier, Richard P., and Raquel Willerman. 1995. "Prelinguistic Gesture in Deaf and Hearing Infants." Pp. 391–410 in Language, Gesture, and Space, edited by K. Emmorey and J. Reilly. Hillsdale, NJ: Lawrence Erlbaum Associates
