Poverty of the Stimulus

Glossary of Grammatical and Rhetorical Terms

Linguistic Nativism and the Poverty of the Stimulus
Linguistic Nativism and the Poverty of the Stimulus by Alexander Clark and Shalom Lappin (Wiley-Blackwell, 2011). Wiley Blackwell

In language studies, poverty of the stimulus is the argument that the linguistic input received by young children is in itself insufficient to explain children's detailed knowledge of their first language. Also known as Argument From the Poverty of the Stimulus (APS), Logical Problem of Language Acquisition, Projection Problem, and Plato's Problem.

An influential advocate of this controversial theory has been linguist Noam Chomsky, who introduced the expression "poverty of the stimulus" in Rules and Representations (Columbia University Press, 1980).

The poverty-of-the-stimulus argument has been used to reinforce Chomsky's theory of a Universal Grammar. Here are some examples from famous works of literature and other texts:

Plato's Problem

"[H]ow comes it that human beings, whose contacts with the world are brief and personal and limited, are nevertheless able to know as much as they do know?" (Bertrand Russell, Human Knowledge: Its Scope and Limits. George Allen & Unwin, 1948)

Wired for Language?

"[H]ow is it that children . . . routinely succeed in learning their mother tongues? The input is patchy and defective: parental speech does not seem to provide a very satisfactory, neat and tidy model from which children could easily derive the underlying rules. . . .

Because of this apparent poverty of the stimulus--the fact that linguistic knowledge seems undetermined by the input available for learning--many linguists have claimed in recent years that some knowledge of language must be 'wired in.' We must, the argument goes, be born with a theory of language.

This hypothesized genetic endowment provides children with prior information about how languages are organized, so that, once exposed to linguistic input, they can immediately start fitting the details of their particular mother tongue into a ready-made framework, rather than cracking the code from scratch without guidance." (Michael Swan, Grammar.

Oxford University Press, 2005)

Chomsky's Position

"It is, for the present, impossible to formulate an assumption about initial, innate structure rich enough to account for the fact that grammatical knowledge is attained on the basis of the evidence available to the learner." (Noam Chomsky, Aspects of the Theory of Syntax. MIT, 1965)

Steps in the Poverty-of-the-Stimulation Argument

"There are four steps to the poverty-of-the-stimulation argument (Cook, 1991):

Step A: A native speaker of a particular language knows a particular aspect of syntax. . . .
Step B: This aspect of syntax could not have been acquired from the language input typically available to children. . . .
Step C: We conclude that this aspect of syntax is not learnt from outside. . . .
Step D: We deduce that this aspect of syntax is built in to the mind."​ (Vivian James Cook and Mark Newson, Chomsky's Universal Grammar: An Introduction, 3rd ed. Blackwell, 2007)

Linguistic Nativism

"Language acquisition presents some unusual characteristics . . .. First, languages are very complex and hard for adults to learn. Learning a second language as an adult requires a significant commitment of time, and the end result generally falls well short of native proficiency.

Second, children learn their first languages without explicit instruction, and with no apparent effort. Third, the information available to the child is fairly limited. He/she hears a random subset of short sentences. The putative difficulty of this learning task is one of the strongest intuitive arguments for linguistic nativism. It has become known as The Argument from the Poverty of the Stimulus (APS)." (Alexander Clark and Shalom Lappin, Linguistic Nativism and the Poverty of the Stimulus. Wiley-Blackwell, 2011)

Challenges to the Poverty-of-the-Stimulus Argument

"[O]pponents of Universal Grammar have argued that the child has much more evidence than Chomsky thinks: among other things, special modes of speech by parents ('Motherese') that make linguistic distinctions clearer to the child (Newport et al.

1977; Fernald 1984), understanding of context, including social context (Bruner 1974/5; Bates and MacWhinney 1982), and statistical distribution of phonemic transitions (Saffran et al. 1996) and of word occurrence (Plinkett and Marchman 1991). All these kinds of evidence are indeed available to the child, and they do help. Chomsky makes a telling slip here, when he says (1965: 35), 'Real progress in linguistics consists in the discovery that certain features of given languages can be reduced to universal properties of language, and explained in terms of these deeper aspects of linguistic form.' He neglects to observe that it is also real progress to show that there is evidence enough in the input for certain features of languages to be learned."
(Ray Jackendoff, Foundations of Language: Brain, Meaning, Grammar, Evolution. Oxford Univ. Press, 2002)