What is "poverty of the stimulus"

n. (context linguistics English) The idea that human language cannot be learned by young children with what information they are given, unless they already have an innate knowledge of language or universal grammar.

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.