Behaviorists suggest that language learning is the acquisition of sounds and words resulting from reinforcement. (Skinner, 1953) For instance,
A 2-year-old picked up a ball and said, "Baa." Mom smiled broadly and said, "Good boy! Ball." The little boy repeated, "Baa." Mom responded, "Very good." Mom's "Good boy! Ball." and "Very good." Reinforced the child's efforts and, over time, language developed. (Eggen, 2001)
Social cognitive theory emphasizes the role of modeling, the child's imitation of adult speech, adult reinforcement, and corrective feedback. (Bandura, 1977) An example of this is:
"Give Daddy some cookie."
"Cookie, Dad."
"Good. Giselle gives Daddy some cookie."
Here Giselle's father modeled an expression, she attempted to imitate it, and he praised her for her efforts. (Eggen, 2001)
Both behaviorism and social cognitive theory make intuitive sense. Children probably do learn certain aspects of language by observing and listening to others, trying it out themselves, and being reinforced. Scientists who study the development of language in different cultures, however, believe something else is occurring. (Eggen, 2001)
According to Noam Chomsky (1972), the father of nativist theory, the language acquisition device (LAD) is a genetic set of language-processing skills that enables children to understand the rules governing others' speech and to use these in their own speech. Nativist theory asserts that all humans are genetically "wired" to learn language and that exposure to language triggers this development. (Eggen, 2001)
Most developmental psychologists believe that language is learned through a combination of factors that include both an inborn predisposition, as Chomsky proposed, and environmental factors that shape the specific form of the language. (Eggen, 2001) All these in combination are supported by Vygotsky's constructivist theory.