Nativist theorists hold that the amazing speed and relative ease with which children learn the grammatical rules of the language they hear around them, from a very limited and grammatically incorrect sample of language and without teaching, cannot be attributed to nurture (Chomsky, 2000). This is known as the ‘poverty of the stimulus’ hypothesis – which infers that the language to which children are exposed is poor and therefore cannot account for the acquisition of language. This, however, contradicts the ‘motherese hypothesis’, which holds that speech to children is in fact simpler and easy to understand. Though, clearly, adult-adult speech is likely to be marked by the flaws Chomsky points out.
Chomsky suggests that human beings are endowed with an innate system specifically designed for language learning, which he termed a ‘Language Acquisition Device’. However, he does acknowledge that the LAD needs input from the environment in order to mature, “We can think of the initial state as a ‘language acquisition device’ that takes experience as ‘input’ and gives the language as an ‘output'” (Chomsky 2000, p4). According to Chomsky, the LAD underlies children’s ability to produce utterances they have never heard before and accounts for the universal features of language, i.e. that every language is composed of nouns, verbs, subjects and objects. Indeed the assumption that all languages share the same properties – a ‘Universal Grammar’ and a ‘surface structure’ (organisation of words in an utterance) and ‘deep structure’ (the meaning) is central to the LAD.
He holds that a ‘Transformational Generative Grammar’, a set of rules applied to the deep structure to transform it to the surface structure, underpins the ‘creativity’ in language, i.e. the fact that we can produce an infinite number of utterances from a finite number of words. More recently he proposes a Principles and Parameters theory, the notion that language has universal principles, with parameters being set from language to language (Chomsky, 1986).
The notion that all languages have the same underlying properties, however, seems overly simplistic. All languages do have the same categories of grammar, but in many cases the differences become far more complex. For example, Bates (….) points out that Chinese has no grammatical inflections, whereas Eskimos are confronted with a language in which “an entire sentence consists of a single word with more than a dozen inflections” p16.
A large body of empirical evidence supports the theory that young children grasp grammatical rules and therefore that the ability to use language may be innate.. Furthermore, research findings indicate that children can infer the meaning of novel verbs and nouns from their structural knowledge, hypotheses respectively known as ‘syntactic bootstrapping’ (Gleitman 1999) and ‘semantic bootstrapping’ (Pinker, 1994). It is believed that children use this knowledge to guide their word learning (Brown, 1957). For example, in one study, three- and four-year-olds were shown a picture of a pair of hands sifting through a bowl of red confetti. When asked if they could see “sebbing” the children pointed to the pair of hands, and when asked if they could see the “seb” they pointed to the bowl (Brown 1957). However, it is possible that they are merely drawing short-term inferences, as this does not indicate whether the children actually store the word for subsequent use.
Further, nativists argue that language acquisition follows a predictable sequence of milestones throughout the world and liken it to other maturational occurrences such as walking (Lenneberg, 1967). For example, babbling occurs at around six to nine months – even in deaf children initially, which suggests that language follows a biologically-given pattern. Indeed, there is evidence to suggest that children can learn – and actually invent – a language if exposure to language is minimal or absent, as evidenced in the case of groups of deaf children who develop gestural systems to communicate with one another.
Goldin-Meadow and Feldman (1977) studied such a group of congenitally deaf children aged around three and found that the gestural system they developed shared many similarities with spoken language. Firstly, gestures were used in combinations that seemed to possess a grammatical structure, and secondly, the number of gestures the children were able to use seemed to increase at a similar rate as words in spoken language in hearing children.
Similarly, studies of creolisation, whereby a pidgin language is transformed into a Creole by virtue of being learned by children as a first language, strongly suggest that children impose universal properties on the language they learn. A pidgin is a rudimentary language with very little grammar and is developed by different language communities living together in order that they can communicate. While researching two groups of emigrants to Hawaii around the beginning of the 20th century, the first comprising people who emigrated during adulthood and learned the Hawaiian pidgin (HPE), and the second group comprising those who had emigrated as children and learned HPE while growing up, Bickerton (1981) observed that the children’s language – now known as Hawaiian Creole English (HCE) – possessed a grammar and was fluid, whereas the adult’s language remained inconsistent. Similar findings have emerged from studies into Nicaraguan Sign Language (NSL), which was also created initially as a pidgin language (Pinker 1994).
Nativists also see the evidence for a ‘critical period’ for language acquisition in humans – thought to be up to age 12 – as an indication of innateness. The most compelling evidence in this connection can be found in the case of ‘Genie’, an abused child who spent most of her childhood in a baby crib, deprived of human contact. When she escaped her ‘prison’ at the age of 13, she could not speak and had motor difficulties. Despite years of intensive training in learning how to speak, her vocabulary and cognitive abilities developed significantly, but her syntax never advanced beyond that of a very young child’s (Curtiss, 1977)
However, it has been suggested that Genie was retarded or that the extreme deprivation and abuse she suffered were a major contributory factor (Flanagan, 1996). In contrast, a child called ‘Isabelle’ who was similarly deprived of human contact, and found at the age of 7 with the cognitive abilities of that of a two-year-old child, managed to rapidly catch up with her peers and acquire normal grammar (Davis, 1947). The evidence above would support the hypothesis that language learning becomes almost impossible after the ‘critical period’ (Lenneberg 1967). Importantly, it also lends support to the theory that language is truly innate, an ability distinct from general intelligence (Pinker 1994). While these cases support the theory that we are biologically ‘pre-programmed’ to acquire language, they also illustrate the necessity of input from the environment to allow our genetic endowment to properly develop.
In conclusion, a significant body of empirical evidence into adult-child interaction and language stimulation indicates that the child’s environment is fundamental in the development of language, though not in the way originally perceived by behaviourists and learning theorists. Similarly, there is strong evidence to indicate that humans may be predisposed to learn language: language is confined to humans, the brain is specialised for language, there are universal milestones in language acquisition, language seems to have universal properties and there seems to be a critical period for language development. In reality, neither nature nor nurture in isolation can explain the emergence of language and the two seem inextricably linked.
Unlike the social interactionist approach, neither the traditional behaviourist approach nor the nativist approach acknowledges that the child in turn acts on his environment. It therefore seems that a combination of various aspects of nativism and various aspects of social interactionism would more adequately explain the relative contributions of nature and nurture in language development.
References
Bandura, A (1971) An analysis of modeling processes in A. Bandura (Ed)
Psychological Modeling New York: Lieber-Atheron
Berko, J. (1958) The Child’s learning of English Morphology. Word, 14 150-177
Bates, E; McNew, S; MacWhinney, B; deVescovi, A; and Smith, S (1982) Functional constraints on sentence processing: a cross-linguistic study Cognition 11. p245-299
Bickerton, D (1981) Roots of Language Ann Arbor, Michigan: Karoma
Braine, M.D.S. (1971) The acquisition of language in infant and child in C.E. Reed (Ed)
The Learning of Language New York: Appleton-Century-Crofts