PSYCHOLINGUISTICS
THE NATURE PROBLEM AND STRESS AT THE FIRST LANGUAGE ACQUISITION
These theories, championed by the likes of Noam Chomsky and others, include innatism and Psychological nativism, in which a child is born prepared in some manner with these capacities, as opposed to other theories in which language is simply learned as one learns to ride a bike. The conflict between the traits humans are born with and those that are a product of one's environment is often referred to as the "Nature vs. Nurture" debate. As is the case with many other human abilities and characteristics, it appears that there are some qualities of language acquisition that the human brain is automatically wired for (a "nature" component) and some that are shaped by the particular language environment in which a person is raised (a "nurture" component). Language acquisition is the process by which humans acquire the capacity to perceive and comprehend language, as well as to produce and use words to communicate. Language acquisition usually refers to first language aquisition, which studies infants' acquisition of their native language. A range of theories of language acquisition have been proposed in order to explain this apparent problem. Language acquisition is part of the overall development of children physically, socially, and cognitively. There is strong evidence that children may never acquire a language if they have not been exposed to a language before they reach the age of 6 or 7. Children between the ages of 2 and 6 acquire language so rapidly that by 6 they are competent language users. By the time children are of school-age, they have amazing language ability; it is a seemingly effortless.

Another supporter of the process of language acquisition that is nature is Derek Bickerton (Brown, 2000:35). He did some research on the provision that brought humans from birth (innateness) and get some significant evidence. The evidence reveals that humans actually have "biologically programmed" to switch from one stage of language to the next stage of language and the human hard-wired from birth to produce a specific linguistic properties at a certain developmental age as well (Brown, 2000:35). Thus language acquisition is not determined by the conditions given in children but is determined by a process running by itself since the child is born into the world along with knowledge of the language and the age of maturity of the child.
In this first lecture I look at two ways of accounting for how a child acquires its mother tongue. The first, drawn from the work of the linguist Noam Chomsky, sees language as a specific skill, its acquisition governed by an inborn programme, and requiring no direct intervention from parents or teachers. The second, advanced by Jerome Bruner and rooted in Lev Vygotsky's theories of development, sees the behaviour of the child's entourage as crucial.
Acquisition (as opposed to learning) depends on children receiving linguistic input during the critical period. The critical period is defined as the window of time, up to about the age of twelve or puberty, in which humans can acquire first languages.
Conclussion
First language acquisition differs from second language learning in that children acquire first languages innately and passively while adults learn second languages actively through explicit education and instruction. Older children and adults past the critical period can successfully learn second languages through language immersion. However, many language learning programs that promise language acquisition through immersion fail to take into account the differences between first language acquisition and second language learning as well as the necessary linguistic environment for authentic language immersion. Nonetheless, language immersion programs can reinforce the learning that language learners gained through explicit second language education and instruction.
Resource
http://www.stanford.edu/~inbalar/TA%20language%20acquisition/L240-syll-1.pdf
http://www.uky.edu/~tmclay/First%20Language%20Acquisition.ppt
http://addi-muhaemin.blogspot.com/