In linguistics, the poverty of the stimulus (POS) is the assertion that natural language grammar is unlearnable given the relatively limited data available to children learning a language, and therefore that this knowledge is supplemented with some sort of innate linguistic capacity.
Nativists claim that humans are born with a specific representational adaptation for language that both funds and limits their competence to acquire specific types of natural languages over the course of their cognitive development and linguistic maturation. The argument is now generally used to support theories and hypotheses of generative grammar. The term "poverty of the stimulus" was coined by Noam Chomsky in his work Rules and Representations. The thesis emerged from several of Chomsky's writings on the issue of language acquisition. The argument has long been controversial within the field of linguistics, forming the backbone for the theory of universal grammar. Arguments in support of poverty of stimulus are not attempting to appeal to innate principles in exchange for learning appellates of universal grammar.
Although Chomsky officially coined the "poverty of the stimulus" theory in 1980, the concept is directly linked to another Chomskyan approach named Plato's Problem. He outlined this philosophical approach in the first chapter of the "Aspects of the Theory of Syntax" in 1965. Chomsky asserts that there is a physiological component in the brain that develops in children, and thus, they are able to acquire language universally. Plato's Problem traces back to "Meno", a Socratic Dialogue. In Meno, Socrates "undigs" mathematical knowledge of a servant who was never explicitly taught the geometry concepts. Plato's Problem directly parallels the idea of the innateness of language, universal grammar, and more specifically the poverty of the stimulus argument because Socrates discovered people's innate ability to fully understand foreign concepts that they are never exposed to. Chomsky illustrates that children are not exposed to all structures of language, yet they fully achieve the necessary linguistic knowledge at an early age.