Language Acquisition in Young Children

I just finished reading Michael Tomasello's book, The Cultural Origins of Human Cognition (1999), and I was quite interested in his views concerning language acquisition in young children. Tomasello describes the dynamics between a parent and a child and how learned behaviour, including language, is the result of the communicative relationships between them. He asserts that language acquisition depends on a child's exposure to cultural stimuli, so that the child can develop linguistic capacities such as imitation, joint attention, and discourse. This theory demonstrates that the acquisition of language depends on the acquisition of culture. This blog post follows Tomasello's argument and contrasts with linguist, Noam Chomsky, who asserts that language acquisition is innate.  The emerging question from my research is: "What happens to a child if she is deprived of culture during the formative years?"

Tomasello rejects Noam Chomsky's theory of innate language development. In his book, The Chomsky/Foucault Debate (2006), Noam Chomsky asserts that universal grammar is hard-wired into the brain and manifests without being taught.  He supports his theory by offering an analogy of a lamb who is taken away from its mother and raised in isolation. The result is that the lamb will not develop depth perception. Chomsky asserts that the mother does not teach the lamb depth perception, but that she somehow enables the lamb's visual system to work the way in which it is designed (p. 173). He suspects that language acquisition in the human brain works the same way (p. 179). 
 
In contrast, Tomasello argues that an infant's brain is genetically prepared versus hard-wired.  In his book, Constructing a Language (2003), Tomasello asserts that the genetic preparation cannot be too specific.  He states that children must be flexible enough to learn not only hundreds of thousands of individual words, expressions, constructions and conventional expressions of language, but also the different types of abstract constructional patterns that language has grammaticized historically (p. 1,2). 
 

Research in neuroscience tends to support Tomasello's theory.  In an article entitled, Building Baby's Brain: The Basics (1998), Dr Diane Bale describes the genetic preparation for the learning process. She describes how a baby's brain has more than one hundred billion brain cells. Bale says that most of the connections are done after the baby is born except connections needed for physical body functions such as heart beat and motor functions which develop in utero. However, through learning, the child's brain cells have made many more connections by the age of three.  The brain keeps track of connections that the baby uses most.  In time, the brain gets rid of the connections that it does not use regularly.

Human infants are born completely helpless. Their helplessness may be the reason they are social from birth; their very survival depends on it.  Tomasello describes that much of the initial engagements between a parent and child “involve looking, touching and vocalizing in ways that serve to express and share basic emotions” (Tomasello, 1999, p. 59). As infants develop, they learn through mimicking with basic “tongue protrusions, mouth openings, and head movements” (p 59). Then Tomasello refers to the “nine month revolution where infants begin to behave in ways to suggest that they understand their social worlds (p. 61). He refers to these behaviours as joint attentional behaviours that indicate an emergence of the self and others as distinct ( p. 62). At around eight months of age, infants begin to act with intention toward a goal which indicates a higher level of functioning (p. 73).

As a mother, I am especially interested in the discourse that takes place between a parent and infant and the resulting development of vocabulary and understanding of social contexts. Tomasello suggests that parents who spend time talking to their infants have infants who develop larger vocabularies (Tomasello, 1999, p. 110).  It is interesting to note that discourse surrounding an object that the infant is focused on is more beneficial to the infant's vocabulary than a parent who directs the infant's attention away from the object to something new (p. 110). As shared relationships continue through joint-attention, infants learn to internalize perspectives of themselves and perspectives of another other person. Around two years of age, children are able to think abstractly by using objects as symbols. “For example, a twenty-four-month-old year old might push a block along the floor and make noises such as 'Vroom!'” (p. 129). Tomasello proposes that “children learn to use objects as symbols in much the same way they learn to use linguistic symbols” (p. 129). Note that children's use of objects as symbols and their acquisition of linguistic symbols emerge around the same time (p. 129).

Tomasello's work has left me deeply curious about feral children and/or children who are otherwise isolated from social contact and culture. Not much credibility is given to accounts of feral children due to the lack of documentation and and sensational media stories which gives rise to hoaxes. I did however come across one heartbreaking story of abuse and neglect: Genie: A Scientific Tragedy (1993). Genie was kept isolated in a room from birth until her rescue at age 13. Most of her days were spent tied to a potty chair. When she was rescued, she could not speak and could hardly walk. She was subsequently subject to scientific trials, later coined "The Forbidden Experiment", to see if she could learn to speak after the critical period for language acquisition during the formative years. The scientists had some success and her vocabulary increased to approximately one hundred words. However, she had difficulty with pronunciation and did not have the ability to form a coherent sentence. She would say, “applesauce store buy” instead of, "buy applesauce at the store". Unfortunately, her story does not have a happy ending. Genie regressed after she was abused in a foster home. She never spoke again.

I recommend viewing the rest of Genie's story which is a six part video series.  There are a lot of unknown variables in terms of assessing Genie's ability or inability to acquire language.  For example, it is clear that she was exposed to language throughout her isolation although the words were likely minimal and negative.  Her personal history was so disastrous that it would not be at all clear why she had been unable to make progress.  According to Chomsky's theory, Genie did not progress because she would have surpassed the critical time to develop language.  According to Tomasello's theory, Genie did not progress because she was not exposed to cultural stimuli during the formative years.  There seems to be a general consensus among theorists that something happens in the brain at puberty that makes language acquisition at an older age very difficult.    

Overall, it is difficult to measure language acquisition in infants without a controlled environment deprived of cultural stimuli and that would be unethical, cruel and inhumane.  As in Genie's case, it would be a forbidden experiment.  In terms of theories, I tend to agree with Tomasello's theory on language acquisition: if an infant is exposed to the cultural stimuli which includes parents who are engaged with her, she will learn language.  Language is a web of complex linguistic symbols that serve to organize and express communicative thoughts.  Therefore, learned language is synonymous with cognitive development and it is a reflection of culture.