Universal grammar is a controversial linguistic theory which states that there are certain characteristics shared by all languages and that humans are born knowing these characteristics. Some linguists try to identify these characteristics, while others study the differences between children and adult language learners to determine what information is innate and what is learned. The basic applications of universal grammar include the study of proposed linguistic universals and the search for a portion of the brain known as the Language Acquisition Device (LAD).
Although the best known proponent of universal grammar is Noam Chomsky, the theory was first talked about years before he was born. Roger Bacon wrote the first universal grammar theory in the thirteenth century, about seven centuries before Chomsky’s 1957 publication Syntactic Structures. Universal grammar is proposed primarily because of the similarities between languages and the poverty of stimulus argument, which states that children learn language almost automatically without receiving enough instruction.
Characteristics that all languages share are called linguistic universals. There two types of universals are absolute and statistical. Absolute universals are those that are true in all known cases, and very few exist. For example, “all languages have pronouns” is an absolute universal. Statistical universals are better known as tendencies because they are true only in the majority of cases, not all.
Linguist Joseph Greenberg developed forty-five universals from his study of approximately thirty languages, and almost all of them were implicational. This type of universal takes the form of an if-then statement, such as, “if a language is spoken, then it has consonants and vowels.” Non-implicational universals are straightforward declarative statements. For example, the sentence “all languages have nouns and verbs,” is a non-implicational universal.
Scientists also conduct cognitive studies based on universal grammar. One theory within universal grammar states that everyone is born with a Language Acquisition Device (LAD). The LAD is a portion of the brain which knows all linguistic universals automatically and enables children to quickly learn a language. Since language learning is more difficult for adults than children, the critical period hypothesis states that the LAD degenerates or becomes increasingly difficult to access as a child grows.
Both applications of universal grammar could greatly increase the ability and ease of learning languages. For example, someone who knows all linguistic universals would have a great advantage for learning every natural language. In addition, if scientists discovered an LAD and learned how to access it throughout life, elderly people might be able to learn languages with the ease of a preschooler.