The Critical Period Recent research has suggested that we not only come specially pre-wired to learn language, but we also have a sort of biological language clock ticking away. As the clock counts closer and closer to a predetermined time, the difficulty with which we can pick up language increases. In regards to second languages, t is still possible for individuals to learn and become rather fluent in languages after the critical period, but they will probably never develop a comparable proficiency that a child who has been exposed to the language since age five or even age ten has obtained. Recently the discussion has shifted to reflect the hereditary influences that seem to be present in humans. Heredity builds the innate psychological mechanisms .
Environment provides input to the innate psychological mechanisms .
Using the new model, we can account for a universal grammar element that is innate in all of us, while still accounting for the variation of languages across cultures. The new presentation also allows for a scientific view of humans as more than automatons who have no basis for a willful self. I'll end with a statement by Pinker that may well become the standard approach to thinking about human behavior. Like language itself, it seems to be a matter of common sense. How the Mind Creates Language.