Language acquisition device; Universal grammar.
Language is an innate faculty which humans are biologically prepared to develop in contrast to other species.
Naturalistic accounts of language acquisition, such as Chomsky’s linguistic nativism, claim that our capacity for producing and understanding verbal correspondence is coded into our brains from birth. On its conception, in his 1959 review of Skinner’s Verbal Learning, this type of explanation stood in contrast to the dominant empiricist views emphasizing learning and conditioning. Previously, researchers had explained linguistic development as a product of external variables, equating it to the vocalizations of other animals. A knowledge of grammar was then believed to be derived from domain general learning mechanisms, with individuals’ capacities for language originating from the conditions of their physical environment. The nativist perspective challenged a prevailing focus on simplistic causal explanations for linguistic development. Instead it addressed the complex organs that allow for language to be produced and comprehended. Accordingly, though the specifics of a language were learned, the human capacity for it was thought to be the product of at least one species specific, genetically endowed, unit. That suggestion marked a paradigm shift in how linguists regarded the internal processes that determine language production and comprehension, and is sometimes credited with spurring the cognitive revolution.
The nativist hypothesis reasons that language faculties emerge as organically as an ability to walk, with children’s brains calibrated to extract content from limited samples of communication. Dedicated linguistic modules are therefore considered a fundamental part of the human genome. Thus rather than thinking of infants as blank slates, nativists characterize them as information processors in possession of an internal knowledge of syntax i.e., the principles and processes which govern form. Ergo people’s capacity for organizing language is treated largely independent of that which they encounter in their surrounding worlds.
Chomksy (1980) notes that often a child’s knowledge of grammar greatly exceeds the inputs and reinforcement they are given. Moreover, their daily use of language will often comprise novel strings of words that have not been previously spoken by or to them. They will also achieve their creative expertise despite rarely encountering negative evidence i.e., information regarding which strings of utterances are not grammatical. These occurrences make it infeasible that their language capacity is learned through habituation. Instead, despite the relative poverty of their stimulus, their brains must have an inherent means to generatively order its limited vocabulary into, or respond to, a seemingly infinite variety of combinations. Hence they can identify Chomksy’s creation “colorless green ideas sleep furiously” as grammatically plausible despite it being semantically meaningless and the odds of them hearing it prior being improbable.
Chomsky (1980) labelled the chief tool, to this acquisition process, universal grammar. This term refers to a set of instinctive language-general principles of categories, mechanisms, and constraints including the ability to distinguish nouns from verbs, or function words from lexical words. One principle is syntax being dependent on structure rather than sequence. In English, a question form of the statement “Dean Robertson will cross the road” sees the third word shifted to before the first and second, to become “will Dean Robertson cross the road?” However, the same technique applied to “the slow chicken will cross the road” results in the ungrammatical form “chicken the slow will cross the road?” Inconsistencies such as this necessitate that speakers have a knowledge of structural components, rather than relying on linearity for clarity. In these examples, “Dean Robertson” and “the slow chicken” are both noun phrases, despite their variable forms. Whereas “will” is future-interrogative and so needs to be moved to the beginning in order to form a question.
Also included in universal grammar are parameters, referring to language-specific variations. For example, English is head-initial, with a noun of verb preceding compliments in the same phrase, while Japanese is head-final. It is these specifications that allow speakers to create syntactically correct sentences that elucidate the relationships between subjects. The continuity assumption (Pinker 1994) suggests these innate parameters are reliable throughout people’s lives meaning, once developed, young children’s syntactic competence matches that of adults. The amount and scope of principles and parameters are still subject to rigorous debate, with researchers estimating there being anything from tens to hundreds.
Chomsky draws a parallel between thought and language, conceptualizing the latter to be a means of externalizing the former. In doing so he reverses the Aristotelian view of speech as sound with meaning, by labelling it meaning with sound. Yet he stops short of analyzing its adaptive origins in terms of the specific demands it had to meet. Other researchers have attempted to tackle this issue, so as to align knowledge of why humans have language with how it works. Notably, Dunbar (1993) explored its origins as a means to allow for vocal grooming, or gossip, by permitting simultaneous interactions between multiple members of a social group. Pinker (1994) agrees with language being an instinct akin to spiders weaving webs or beavers constructing dams. Though he suggests its purpose was to meet the reliance on knowledge that would have been crucial to the continued survival of hunter-gatherer societies. What both of these theories have in common is they support the nativist model in suggesting that language acquisition is not a byproduct of general learning tools.
This is not to suggest language acquisition is inevitable under nativist accounts. Rather, it has been claimed that children require access to samples of a naturally occurring inputs to initially stimulate the process. Lenneberg (1967) speculated a salient role of biological age, anticipating a critical period for language acquisition between 18 months and early puberty most people. Similar phenomena have been seen in cross-species, with researchers determining the effects that the timing of relevant environmental inputs can have on how attuned an organism’s capacities are to the environment it has been exposed to e.g., imprinting in young animals. As per Chomsky’s nativism, this theory suggests language occurs through maturation instead of feedback. Lenneberg argued that this constraint is owed to a decrease in neural plasticity following hemispheric lateralization, where evidence for lateralization in language is robust.
Outside such a timetable, a child will be neither able to learn, nor meaningfully produce, language regardless of the inputs that follow. But provided this threshold is reached then they ought to learn it without a need for formal tuition. While the critical period has since been revised to a sensitive one, following some exceptional data, there appears to be a consensus that age is a key issue in learning a first language.
Evidence for Linguistic Nativism
The best evidence of linguistic nativism is in the seemingly streamlined process by which language, including sign, is acquired. From any other species, the most intelligent member would be unable to achieve that which we expect from any normally developing one of our own. Whether they are raised in a small mountain village, or a vast metropolis, children encounter equivalent milestones in the same order, despite often considerable variance among their inputs where Brown (1973). Their use will also be creative and not necessarily tied to a context, like the communication systems of other animals empiricists had thought analogous. It would be difficult to explain this humanity-wide mutual incidence, and the resultant grammatical consensuses, through nonbiological models. A uniform schedule, regardless of the quality of exposure, therefore hints at an innate underlying cause. Furthermore, to test the poverty of the stimulus argument Marcus (1993) explored the feedback that young speakers receive. In outlining the inadequate responses, that corrected meaning over grammar, he suggested internal factors and an innate knowledge must be crucial to constraining their generalizations e.g., past tense errors like “maked” or “goed.”
A biological premise for language is further supported by consistent patterns of specific linguistic faculties being deleteriously impacted, following damage to particular neurological regions, despite other cognitive capacities remaining intact (Hickok and Poeppel 2007). Modern imaging techniques, along with neuropsychological data, have revealed a network of regions specialized to comprehending language or articulation. Popular examples include the frontotemporal region, being localized to enunciation, the posterior temporal area being linked to understanding and the bridging tract to repetition. Combined these deficits reinforce language as a natural phenomenon, by highlighting a network of neurological substrates selectively dedicated to its function in the absence of obvious associations with other abilities.
Tragic childhood neglect stories suggest that the roles of these regions are subject to a sensitive period (discussed in Pinker 1994). Famously, Genie was rescued from prolonged isolation at age 13. While she regained some of her language capacities, including basic syntax and an ever-growing vocabulary, she was unable to apply or follow complex grammatical features. This deficit continued despite her being subject to a stimulus-rich environment which actively encouraged her to learn: something that would have nurtured her abilities according to empiricist accounts. In contrast, Isabelle was saved aged six and a half and was soon able to learn language and to use it as meaningfully as her peers. There are ambiguities surrounding the specific role of trauma, or the condition of each subject prior to their mistreatment. Even so, the stark difference in recovery between these examples advocates the existence of a time restricted window important for normal development.
A more routine illustration of the same phenomenon can be found in adults acquiring a second language, with some data showing a linear relationship between age of learning and subsequent struggles (Patkowski 1980). This line of research is considerably less conclusive than the case studies, with many notable instances of learners beginning in adulthood and still achieving fluency. Nevertheless, it is generally acknowledged that some aspects, such as picking up the native accent, are limited to children being raised with a second language and not adults gaining one. For that reason it may be the neuromuscular components, such as phonology and pronunciation, which are subject to a sensitive period versus the contents of speech per se (Singleton 1995). However, comparisons with the unguided character of first language acquisition are potentially limited since adults learning a second language will typically do so intentionally.
Chomsky’s seminal 1950s critique of empiricism provided a new layer of analysis for thinking about language, arguing that previous means had proven inadequate. Here, he extended a topic most frequently thought of through the lens of observable patterns and conditioning into an area ripe for interdisciplinary research. In particular, he called for a computational approach to linguistics that emphasized the species-exclusive nature of its bestowal. Universal grammar is a concrete theory that can be used to explain recurrent findings in the linguistics literature, including standardized procurement and selective dysfunction following lesions. That a young boy will learn to talk, in a way that his puppy never will, ties the aptitude to our unique biology. But prior to Chomsky, there was minimal consideration of its relative contribution or the mechanisms that may underlie it. Nativism changed this by adding modularity to the lexicon with which language, along with how other cognitive functions, was thought about. The details of this model, along with its evolutionary source and the comparative role of culture, are still hotly contested today. Nonetheless, the framework provides a means to better understand how humans are able to generate speech so effortlessly, be it for the most urgent or trivial matters.
- Chomsky, N. (1980). Rules and representations. New York: Columbia University Press.Google Scholar
- Lenneberg, E. H. (1967). Biological foundations of language. New York: Wiley.Google Scholar
- Singleton, D. (1995). A critical look at the critical period hypothesis in second language acquisition research. In D. Singleton & Z. Lengyel (Eds.), The age factor in second language acquisition: A critical look at the critical period hypothesis (pp. 1–29). Clevedon: Multilingual Matters.Google Scholar