12.2: Theories of language development

Humans, especially children, have an amazing ability to learn language. Within the first year of life, children will have learned many of the necessary concepts to have functional language, although it will still take years for their capabilities to develop fully. As we just explained, some people learn two or more languages fluently and are bilingual or multilingual. Here is a recap of the theorists and theories that have been proposed to explain the development of language, and related brain structures, in children.

We are not born with language because computer learning models show that language like capacity can develop. So it is true that language and cognition are not separate. In general language development entails early neural networks, particularly in Broca’s area, becoming dedicated to language ability. However, Broca’s area is damaged at birth, other brain areas can compensate pretty easily. Language is cognition.

Language is embodied – for example researchers have found that brain areas representing the sensorimotor aspects of words get activated when a child is stimulated with the word (or another word taught to represent that activity). However, it could also be that that depends on the environment. The language that is merely symbolic might remain symbolic in the brain as well, whereas the part that is embodied becomes embodied in the brain. But there is no agreement about the connection between language, cognition and our sensorimotor systems.

There is also the thought that language influences cognition and how we think about space and navigation. In some cultures, language giving directions does not use personal orientation but rather only cardinal directions. Those languages force people to be better at knowing where they are in space etc.

The following two theories of language development represent two extremes in the level of interaction required for language to occur (Berk, 2007).

Chomsky and the Language Acquisition Device

The view known as nativism advocated by Noam Chomsky suggests that infants are equipped with a neurological construct referred to as the language acquisition device or LAD that makes infants ready for language. Language develops as long as the infant is exposed to it. No teaching, training, or reinforcement is required for language to develop.

Noam Chomsky’s work discusses the biological basis for language and claims that children have innate abilities to learn language. Chomsky terms this innate ability the “language acquisition device.” He believes children instinctively learn language without any formal instruction. He also believes children have a natural need to use language, and that in the absence of formal language children will develop a system of communication to meet their needs. He has observed that all children make the same type of language errors, regardless of the language they are taught. Chomsky also believes in the existence of a “universal grammar,” which posits that there are certain grammatical rules all human languages share. However, his research does not identify areas of the brain or a genetic basis that enables humans’ innate ability for language.

Skinner: Operant Conditioning

B.F. Skinner believed that children learn language through operant conditioning; in other words, children receive “rewards” for using language in a functional manner. For example, a child learns to say the word “drink” when she is thirsty; she receives something to drink, which reinforces her use of the word for getting a drink, and thus she will continue to do so. This follows the four-term contingency that Skinner believed was the basis of language development—motivating operations, discriminative stimuli, response, and reinforcing stimuli. Skinner also suggested that children learn language through imitation of others, prompting, and shaping.

Social Pragmatics

Another view emphasizes the child’s active engagement in learning language out of a need to communicate. The child seeks information, memorizes terms, imitates the speech heard from others and learns to conceptualize using words as language is acquired. Many would argue that all three of these dynamics foster the acquisition of language (Berger, 2004)[1].

Piaget: Assimilation and Accommodation

Jean Piaget’s theory of language development suggests that children use both assimilation and accommodation to learn language. Assimilation is the process of changing one’s environment to place information into an already-existing schema (or idea). Accommodation is the process of changing one’s schema to adapt to the new environment. Piaget believed children need to first develop mentally before language acquisition can occur. According to him, children first create mental structures within the mind (schemas) and from these schemas, language development happens.

Vygotsky: Zone of Proximal Development

Lev Vygotsky’s theory of language development focused on social learning and the zone of proximal development (ZPD). The ZPD is a level of development obtained when children engage in social interactions with others; it is the distance between a child’s potential to learn and the actual learning that takes place. Vygotsky’s theory also demonstrated that Piaget underestimated the importance of social interactions in the development of language.

Piaget’s and Vygotsky’s theories are often compared with each other, and both have been used successfully in the field of education.

Figure \(\PageIndex{1}\): This park ranger is using the ZPD to increase these boys understanding.[2]

The support for Vygotsky’s theory about the importance of social interaction in cognitive development can be further supported by the data showing the effects of SES on language acquisition as illustrated by this section from Arduini-VanHoose’s work[3]

Psychologists Betty Hart and Todd Risley (2006) spent their careers looking at early language ability and progression of children in various income levels. In one longitudinal study, researchers found that although all the parents in the study engaged and interacted with their children, middle- and high-income parents interacted with their children differently than low-income parents. The researchers found that middle- and high-income parents talk to their children significantly more, starting when the children are infants. By age 3, high-income children knew almost double the number of words known by low-income children, and they heard about 30 million more words than the low-income counterparts (Hart & Risley, 2003). These gaps become more pronounced by kindergarten, with high- income children scoring 60% higher on achievement tests than their low-income peers (Lee & Burkam, 2002).

The achievement gap refers to the persistent difference in grades, test scores, and graduation rates that exist among students of different ethnicities, races, and—in certain subjects—sexes (Winerman, 2011). Research suggests that these achievement gaps are strongly influenced by differences in socioeconomic factors that exist among the families of these children. Low-income children perform significantly worse than their middle- and high-income peers on a number of educational variables: They have significantly lower standardized test scores, graduation rates, and college entrance rates, and they have much higher school dropout rates. Many of these problems start before the children even enter school.

There are solutions to this problem. Experts are working with low-income families to encourage them to speak more to their children and designing preschools in which students from diverse economic backgrounds are placed in the same classroom (Schechter & Byeb, 2007).

Critique of these theories

These different theories of language acquisition might seem disparate and irreconciliable, while on the other hand it is pretty clear that each of them are very correct in the claims that they make when we look at the fact that an overwhelming majority of people communicate using language. Patricia Kuhl (2007)[4] has conducted a lot of research on the neuroscience of language and suggests that infants’ brains are wired to recognize and produce language, but that those brain areas go through developmental stimulation where the wiring changes in response to the sounds that babies hear. So infants under 6 months old are able to hear and produce all of the phonemes (about 600 consonants and about 200 vowels) that all human languages use collectively. However, between 6-8 months of age, infants become better at recognizing the phonemes of the language/s that they are hearing around them (about 40 in most languages), and become worse at distinguishing between the sounds of other languages that are not being used in their environment. This falls in line with the idea of a critical or sensitive period for language acquisition. The idea is that neural networks are have a potential or are ripe for developing. Then depending on the auditory stimulation that the child receives, the networks “commit” to the language/s heard. But Kuhl also points out that it is not only auditory stimulation – such as heard through a television monitor, but rather a person interacting with the child that influences these networks to form and stabilize. She theorizes that this requirement of human interaction as a basis for language acquisition might be mediated by emotional arousal and motivation, in addition to the information gained by a live tutor who shares attention, points at objects and so on while providing the auditory stimulation necessary for language acquisition.

Much of the early research on this was done using sucking on pacifiers that were attached to computers recording the sucks, or noting when infants turned their heads in response to sensory discrimination (when the sound changed from ra to la for example). Current research can be done using EEG and ERP recordings, as well as MEG to note whether and which parts of the brain are responding to language. MEG studies have shown that in infants as young as 6 months, Broca’s area is activated in response to language sounds, perhaps in a mirror neuron type of response.

References:

[4] Kuhl, P. K. (2007). Cracking the speech code: How infants learn language. Acoustical Science and Technology, 28(2), 71-83. https://doi.org/10.1250/ast.28.71, https://www.jstage.jst.go.jp/article...ticle/-char/en

Attributions:

Child Growth and Development by Jennifer Paris, Antoinette Ricardo, and Dawn Rymond, 2019, is licensed under CC BY 4.0

[1] Children’s Development by Ana R. Leon is licensed under CC BY 4.0

[2] Image by the National Park Service is in the public domain

[3] Lifespan Development: A Topical approach by Arduini-van Hoose, 2022 licensed CC-BY-NC-SA 4.0