How Babies Learn Language

I watched this TED talk by Patricia Kuhl about a year ago, or sometime while I was pregnant with Ju. I remember being fascinated by what development psychologists were discovering about babies and how they learn language, particularly foreign languages.  Dr Kuhl gave a more in-depth lecture at the University of Washington, available for view on Youtube, but the TED talk summarises her research findings in a short couple of minutes.

The Golden Window

In a nutshell, the facts are pretty indisputable: babies are able to discern all the sounds of all languages in the word up till a certain age -- 10-12 months. Kuhl posits that between 8 and 10 months, all babies begin to take rapid statistics of adults' speech and these statistics are then used in later stages for their speech development. But get this, after 10 to 12 months of age, babies' ability to detect other languages other than the one they are most exposed to (the mother or native tongue) drops significantly. 

The science is simple: after the 8 to 10 month window when babies are rapidly taking statistics of the sounds they hear in adults' speech, the ones who are NOT exposed to more than one language start to tune out the foreign language sounds in order to focus on the native language sounds. Kuhl experimented with American babies at age 7-8 months, testing their ability to discern Chinese language sounds. All the babies could do so.  Then, one set of babies were exposed to 12 sessions of 35 minutes of Chinese (over 12 weeks) during the critical window and another group (the control group) were not.  The babies that were not exposed to any Chinese lost their ability to discern the Chinese sounds but the exposed group of babies were able to discern the sounds!

Kuhl argues that as native language acquisition begins at the 7 to 10 month stage (where babies start to actively take speech statistics), foreign language acquisition declines because all the babies are hearing are one language, their native tongue, unless of course, they are being raised bilingual or multilingual.  This also explains why adults have a horrible time picking up foreign languages, particularly after their teens. The OPTIMAL age span for learning language is from age 0 to 7. After that it decreases slightly and then dips at purberty. After that, it's just downhill.

Putting Science To Practice

I have always been a fan of science and experimentation. In fact, I've been testing Ju for a couple of weeks on his object permanence cognition. (Still negative, if you're wondering) Anyway, Dr Kuhl's research really stoked my excitement about language learning and how I can possibly help Ju in our multilingual project. To refresh your memory, here's the map of Ju's linguistic inputs. I've added in what I consider an assessment of the degree of exposure: High Exposure is where he hears the language passively as well as actively spoken to him on a daily basis. Medium High refers to daily exposure at a somewhat lesser degree, maybe 1 to 3 hours.

Ju has had this type and degree of exposure since birth.  If the research is valid, then this is the crucial period where Ju is taking statistics, absorbing German, Chinese and English. Dr Kuhl explains that it is through "motherese" (the universal way that people speak to their kids, in a high pitch, repetitive way) that the babies are able to take their statistics. When we speak "motherese", our speech becomes slower, vowel sounds are extended ("Hiiiii Babyyyy!" instead of "Hi Baby!") and as a result, we produce better acoustics, our articulation of words and sentences is clearer, and hence these form the “little nuggets” that map your baby's brain as he absorbs the sounds.

Newsflash for those who think popping in a DVD with Chinese songs in bright, fun animation is going to help your child pick up Chinese.  The study also measured the effect of audio and audio/visual input on the babies. Result? No result. The babies who heard or watched a videorecording of the very same Chinese lessons given to the "exposed" group had no significant improvement in their ability to discern Chinese sounds.

Learning is SOCIAL, i.e. the social part of our brains are responsible for language acquisition.  Not surprising, since it was during constant exposure to my in-laws or other people while I was in Germany that my German improved at the most tremendous rate.  They don't recommend "immersion" for nothing.
So don't be lazy and take heart!  Every child can learn multiple languages and the best way to do it is through interaction. Throw away the DVDs and shut off the television and computer. Your child is like a piggy-bank with a supercomputer, the more you speak, read and expose him/her to languages, the more likely that one fine day the supercomputer will start churning out the very things you hoped to hear.