Human language is a complex communication system with developed grammatical organization and unlimited meaningful combination of phonemes. Even though the system is complex, every normal developing child learns all aspect of language in a short amount of time (grammar, vocabulary etc.).

Researchers are investigating the underlying reason of language acquisition in children for decades. This led to different set of arguments and the two common ones are nativist and social interactionist perspective. The main purpose of this article is to express and compare two different perspectives.

Nativist Theories

According to nativist theories, language acquisition is a modular ability and all humans are born with the same capacity to learn the language. From this perspective, there is less emphasis on the role of social interaction and cultural variability. Noam Chumsky is a leading theorist in this perspective, and he claims that there is an innate system called language acquisition device (LAD) that leads to formulate words grammatically to sentences as soon as children master some vocabulary (Pulgram, 1971). LAD is a domain-specific module in the brain independent of general cognitive abilities, which leads children to abstractly formulate rules in his native language without any influence of present environmental cues.

Neuroimaging studies also support this view that there are some specialized areas in human brain, located mostly in the left hemisphere. These areas are specialized for language comprehension and production (Berk, 2006). Impairments in these areas lead to some linguistic problems, as inability to understand speech. These sentences are produced in grammatical rules however these impairments do not affect performing non-verbal IQ tasks (Gopnik and Crago, 1993 cited in Pinker, 1995). Moreover, there is an area in the brain called left IFG and studies demonstrate that it is specialized for grammatical processing where neural activation is strengthened when a person is advanced in grammatical knowledge when learning a second language (Sakai, 2005).

All these findings support Chumsky’s theory of innate “universal grammar” that these areas may be specialized internalizing grammatical structure, and it leads to acquisition of language. If there are modularities in the brain, very young children should master the grammatical rules is a short duration of time. Research shows that very young children use verbs in correct grammatical rule even on words that are unknown to them, for instance pseudowords (Pinker, 1995). Moreover, small children tend to apply these rules to irregular words such as “win – winned” (Marcus, 1996). This is called over-regularization, this ability of children gives an important hint on initial language development stages.

Over-regularization supports and innate language development system because if language production is derived from interactions with external environment, children should use verbs with right irregular forms because they hear the correct version of words from adults. According to Rule-and-Memory Model, there is a default version which is always dependent on, however as people grow up they tend to less over-regularize because the correct form is stored in their memory (Marcus, 1996). 

According to another nativist perspective, language acquisition is not acquired via grammatical structure but via speech segmentation ability (Kuhl, 2000). This is called categorical perception that infants can segment all sorts of speech as they come to their first age, then they start to lose this ability and perceive sound in categories (Kuhl, 2000). Thus, children create sort of cognitive maps in the brain that detects speech and tries to match it with possible sound and candidate words. To achieve this, environmental factors and learning ability is important as well as native skills.

Even though nativist perspective is supported by many empirical studies, it is inadequate to explain the underlying reason of language acquisition. There is too much emphasis on language acquisition yet not lots of emphasis on other aspects such as semantics and pragmatics. Furthermore, Chumsky mentions that a child innately formulates grammatical rules as soon as vocabulary is gained, yet there is not a clear explanation on how vocabulary is gained. There is also a weakness in Rule-and-Memory model that there are differences across languages. For instance, Spanish has 16 different verbs with many irregulars compared to English that would take much longer to acquire the correct version of the verbs. However, normal developing children master on language approximately the same time (Berk, 2006).

Social Interaction Theories

Lev Vygotsky is one of the most influential theorists who support social interaction perspective. According to him, Zone of Proximal Development (ZPD) is the core of language acquisition. ZPD refers to the notion that children learn a certain level of information by themselves and beyond that level “expert intervention” occurs, which is social interaction with caregivers or adults (Berk, 2006). There are some empirical studies that support ZPD. For instance, in a study mother’s attitude to 2-year-old and 10-year-old children were compared, and it was found that mothers use more simplified language when talking to toddlers, so they create a proper learning environment for children (Snow, 1972).

B.F. Skinner is another social interaction theorist who claims that language is acquired via instrumental conditioning (Berk, 2006). According to him, social interaction plays a role in language acquisition by providing positive reinforcement and feedback. Thus, social interaction provides positive reinforcement and feedback. An empirical work that supports this theory comes from Moet that he conducted a longitudinal study on male and female infants while they were interacting with their mother. According to results, there were nine teaching techniques of mothers and thirty-seven learning strategies of infants.

Michael Tomasello is another social interactionist theorist who claims that human cognition has been evolved to understand intentionality of other agents (Tomasello & Rakoczy, 2003; Tomasello et al., 2003). According to this theory, humans go through two important developmental phases: at age one and at age four. At age one joint attention develops and at age four theory of mind. These two phases lead to emerge of linguistic abilities.

• Joint attention: Infants begin to acknowledge others as intentional agents.
• Theory of mind: Children begins to realize that other people have thoughts, and it is different from              their own.

Tomasello’s theory could be contrasted with Chomsky’s theory that he finds LAD innately acquired, however Tomasello’s theory is the result of other social-cognitive abilities. On this point, an important question may arise that “Why is language unique to humans according to Tomasello's theory?” Autism studies support Tomasello’s theory that people with autism lack joint attention, and they cannot acquire language completely as normal people do  (Baron-Cohen, 1995). Unlike normal infant language development, there is no babbling or gesturing at the age of 12 months old autistic infant (Baron-Cohen, 1995). Therefore, it could be concluded that the deficiency in joint attention and theory of mind capabilities in autistic lead to impaired acquisition of language, follows the same pattern Tomasello’s theory.

There are certain criticism toward social interaction theories. Animal studies show that chimps raised in home environments that have the same condition as humans in caregiving learn limited when compared with human infant (Atherton, 1974). Despite some efforts are given, chimps learn limited when compared with human infants (Atherton, 1974). Additionally, there are huge amounts of cultural and environmental differences between humans however all children start babbling when they are 6 months old, say their first word at age 1, start combining words at age 2, and they start using language with all the complex rules (Berk, 2006). Finally, it takes 5 years for a child to acquire cognitive abilities and age 5 is late for a child to master the language as Tomasello’s theory claim. Language should be before other cognitive abilities because to think abstractly it must have gained semantic knowledge and can categorize objects in a meaningful way. Thus, language should be before other cognitive abilities, even the social ones.

Conclusion

This article explained and compared two common perspectives on language development that are innate and social interactionist theories. Nativist theories argue that there are innate modules for formulating grammatical context of language. On the contrary, social interactionist cues assume that language skills are acquired after birth and developed through interactions with the environment. There are both valid points and weakness of each points. To sum up, nature versus nurture should not be argued as opposite of each other. Rather, they are complementary.

 

References

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Berk, L. A. (2006). Child Development. USA: Pearson Education, Inc.

Kuhl, P. K. (2000). A new view of language acquisition. Proceedings of the National Academy of        Sciences 97[22], 11850-11857.  National Acad Sciences.

Marcus, G. F. (1996). Why Do Children Say" Breaked"? Current directions in psychological science, 5, 81-85.

Pinker, S. (1995). Language acquisition. An invitation to cognitive science, 1, 135-182.

Pulgram, E. (/11). Review: [untitled]. The Modern Language Journal, 55, 474-480.

Sakai, K. L. (2005). Language acquisition and brain development. Science 310[5749], 815-819.        American Association for the Advancement of Science.

Snow, C. E. (1972). Mothers'speech to children learning language. Child development, 549-565.

Tomasello, M., Call, J., & Hare, B. (2003). Chimpanzees understand psychological statesûthe question          is which ones and to what extent. Trends in Cognitive Sciences, 7, 153-156.

Tomasello, M. & Rakoczy, H. (2003). What makes human cognition unique? From individual to shared to collective intentionality. Mind & Language, 18, 121-147.

 

Acknowledgement: The doll illustration in the visualization is adapted from flaticon website.