Chomsky focuses on the mind of the language learner or user and proposed that internal properties of the language faculty are closely linked to the physical biology of humans. He further introduced the idea of a Universal Grammar (UG) theorized to be inherent to all human beings. From the view of Biolinguistic approach, the process of language acquisition would be fast and smooth because humans naturally obtain the fundamental perceptions toward Universal Grammar, which is opposite to the usage-based approach. UG refers to the initial state of the faculty of language; a biologically innate organ that helps the learner make sense of the data and build up an internal grammar. The theory suggests that all human languages are subject to universal principles or parameters that allow for different choices (values). It also contends that humans possess generative grammar, which is hard-wired into the human brain in some ways and makes it possible for young children to do the rapid and universal acquisition of speech. Elements of linguistic variation then determine the growth of language in the individual, and variation is the result of experience, given the genetic endowment and independent principles reducing complexity. Chomsky's work is often recognized as the weak perspective of biolinguistics as it does not pull from other fields of study outside of linguistics.