Post 89: The Critical Period Hypothesis

The Critical Period Hypothesis

The critical period hypothesis states that the first few years of life is the crucial time in which an individual can acquire a first language if presented with adequate stimuli. Language can only be acquired with native like proficiency and accent extending from early infancy to puberty. Unlike first language acquisition, second language acquisition is testable.

Babies acquire language naturally. Babies hear comprehensible input from their parents and when they gain enough linguistic input, they babble in whatever language they are exposed to. If a parent drops a baby in any country in the world, that baby will learn that language. Also, if a baby is exposed to more than one language, it will learn that language with a perfect pronunciation of that language.

Freeman believes that children can pick up language quicker because children have fewer responsibilities than adults whereas adults have to contend with jobs, paying bills, and other adult responsibilities that take adults away from learning a second language. 

Freeman also states that when the brain starts to move intellect usually into the left hemisphere and the right side of the brain begins to store more emotional information, then adults will have more difficulty learning a second language because adults will try to analyze that second language to see if it is similar to the first language. This neurological process where the brain starts assigning certain functions to the left and right hemisphere is called lateralization.  Researchers think that once the brain has lateralized information, adults can no longer learn a second language with a native like accent. Instead, after puberty, adults will speak a foreign language with an accent. 

Young children who have not reached  what Piaget calls, 'the formal operational stage' can still learn a second language with a native like accent. This is why if a baby is exposed to several languages, it will learn those languages with a native like pronunciation. 

Younger children who are still in the 'concrete operational stage' as Piaget puts it can still acquire a native like pronunciation because young children have not yet learned to analyze the structure of the second language.

Once you learn a second language after puberty as mentioned in my previous post on Interlanguage and Fossilization, certain kinds of errors will always persist in the speech of an adult second language learner. In my previous post, I gave the example of the transfer errors my Chinese father makes when he speaks English and that no matter how many times my mother corrects his English, my father always makes the same mistakes.

The Critical Period Hypothesis deals mainly with pronunciation. Adult learners can still learn a second language, but as I have mentioned earlier in this post, they will retain their accent.

I had a room mate with 3 sisters. One sister was 7 when she came to the US from China, another sister was 11 and my room mate came to this country at 13.  The youngest sister speaks English with no accent at all, the 11 year old sister spoke English with a slight Chinese accent and my roommate who came at 13 had a thicker Chinese accent. Curiously, they all had the same /similar sounding voice when they all talked on the phone. I could always tell which sister it was just by listening to how thick the Chinese accent was. If the sister who answers the phone had no accent, that was the youngest sister, medium accent, the middle sister, and the thickest accent was the oldest sister. They all learned to speak, read, write English fluently, just the older the sister was, the more they retained their Chinese accent. Did I mention they all looked alike too?

For parents, if you want your child to learn a language without an accent, then you should expose your child to another language at a young age. There are actually tutoring centers that offer language lessons for toddlers and many well educated parents would drop off their toddlers at these tutoring centers and the tutors would expose the kid to Chinese, French, Spanish, Russian, or whatever language the parent wants. These kids then go home speaking a curious interlanguage of whatever they are exposed to because kids at this age cannot distinguish one language from another yet. Before the brain goes through the lateralization stage, the human brain acts as a sponge and will enable that child to speak with nativelike pronunciation any language he/she is exposed to, thus Chomsky's theory that humans are all wired to learn language and that the ability to learn a language is innate. It is amazing what the human brain can do at a young age. Too bad the brain cannot stay that malleable for adults too!