Babbling

Like I said earlier, Hannah has been making a wide array of fascinating sounds. Luckily, the World’s Most Annoying Sound only lasted a day. Her babbles are mesmerizing, and the consonant sounds are getting clearer. Do they have meaning? The other night, as we were hanging out in her room Brian said to her “dadadadada.” She smiled and said back “dadadadadadada.” They had this proto-conversation at least half a dozen times. It brought tears to my eyes it was so sweet, and scientific skepticism be damned, I’m convinced it was her first truly vocal communication with us. And the next had better be “mamamamamamama.”

Turns out that babbling is not just meaningless vocalizations the province of newscasters, tour leaders, and lonely old women at the fabric store. Early babblings are universal in babies around the world, regardless of culture, or even whether the baby is deaf. Deaf children go through a gesturing phase that is just like vocal babblings in hearing babies. In fact, even songbird chicks also go through a babbling phase before becoming proficient singers. The extent to which this babbling phase is important in developing language was the subject of a 2002 paper in Science – “Left hemisphere cerebral specialization for babies while babbling” (Holowka and Petitto, 297: 1515). The take home message is simple: when babies babble, the right side of their mouths open more, when they smile, the left side opens more, and the mouth stays symmetrical when they are making non-language related sounds. In fact, we all speak like Jean Chretien to a certain extent, but as adults our brains have learned to make faces talking to us look symmetrical. Don’t believe me? Go look in a mirror, take a hand mirror to double your reflection like the hairdresser does, and talk. You might see it.

This reflects the fact that the left hemisphere is where language is processed. Does this mean that as humans we are hardwired for language? The extent to which language development is nature versus nurture is a huge argument that is still ongoing, but there are a couple other compelling reasons to think that language has a strong nature component. There is a genetic component to speech that is partly controlled by the gene FOXP2. The gene itself is ancient, with versions in mammals, birds, even insects. In songbirds, its expression in the brain coincides with the period of greatest song learning. The human version of the protein contains two amino acid differences from that of chimpanzees, our closest relative. Given that the gene is so highly conserved – or so similar – between species, the adoption of two amino acid differences during the evolution of humans from our ape ancestors suggests that these differences imparted a strong evolutionary advantage. Along with physiological changes in the larynx to make complex vocalization possible, changes in FOXP2 may be what make language possible.

So maybe Hannah, before my eyes, is showing me the most unique aspect of her emerging humanity, how she’s learning language.

On the left, my darling girl is smiling because Canada scored during the Olympic Gold Medal hockey game, and you can see that her mouth is slightly more open on the left side. On the right, my darling girl's wail is clearly saying take this stupid hat off me, and the larger opening on the right side of her face indicates to me that she really wishes she had the words to tell me how she really felt.