There was a time when we thought a baby's babbling was simply cute, but there might be more to it than that; Babbling on today's Moment of Science.
A friend of mine recently had a baby, and the whole experience has made her cuckoo. The baby opens its mouth and makes utterly meaningless sounds--you know, ga ga, goo goo--and my friend actually thinks that all that babbling nonsense is a precursor to language. At first, I thought it was total nonsense. But then I began to research the idea.
I found that other researchers have discovered one particular detail about infant babbling that suggests it may very well be a precursor to language. And that is that babies babble more out of the right side of their mouths than the left side.
When talking, adults just happen to open the right side of their mouths more too. Researchers think that this is because neural circuits controlling language are located on the left side of the brain, and each brain hemisphere usually operates the opposite side of the body.
It's only in linguistic activities that people open the right side of their mouths more. For nonlinguistic activities that involve the mouth people tend to open their mouths more symmetrically or on the left side. As a matter of fact, when I first read about this I started watching people when they talk; sure enough most opened the right side of the mouth more.