Final answer:
Early intervention in language development is vital due to the critical periods for development when the brain is most receptive to learning language. Children have a biological predisposition for language acquisition, and if not exposed to language during these critical periods, fluency and grammatical mastery may be compromised.
Step-by-step explanation:
Early intervention is important for language development because of critical periods for development. Language acquisition is an area that has consistently shown that there are optimal periods during early childhood when the brain is especially receptive to language learning. This concept, sometimes referred to as a critical period, suggests that acquiring language is easiest within this early window of life. After this period, learning new languages becomes more difficult, and the ability to become completely fluent may diminish.
Children naturally begin to learn language from an early age and do so through a systematic progression of stages. Babies come prepared with a biological predisposition for language acquisition, as theorized by Noam Chomsky. By being exposed to language, they start to recognize voices, discriminate between different languages, gesture, and eventually form words and sentences. This process tends to peak between nine months and three years of age, a time when children's brains are most malleable and capable of absorbing new information rapidly.
The case of Genie, a child who was deprived of language exposure during her critical developmental years, illustrates the struggles and limitations faced when language learning is attempted after the critical period has passed. While Genie was able to build a substantial vocabulary, her mastery of grammar remained deficient, highlighting the importance of timely language exposure during early childhood.