TABLE OF CONTENTS
2. The Critical Period Hypothesis.
3. The Critical Period Hypothesis and Second Language Acquisition
3.1 Is there a sensitive learning period for pronunciation?
3.2 Is there a sensitive learning period for grammar?
3.3 Is there a sensitive learning period for understanding semantic content?
3.4 The influence of emotion and interest in different age groups of learners
4. Useful learner characteristics for second language acquisition
When it comes to learning a language, there seems to be a certain period in which a child must acquire the basic competences in order to be able to understand and use language. This ´window of opportunity´ is also called ´critical period´ and has been the subject of much research over the last decades.
Especially for future language teachers, the question about the existence of such a critical period for second language acquisition as well arises.
This paper examines the actual research on critical period for second language acquisition and sheds light on the on-going academic discussion.
The paper proceeds as follows: section 2 provides a short description of the Critical Period Hypothesis and sheds light on biological and neurological aspects of language learning. In section 3 recent findings of research according to critical periods in second language acquisition are presented and discussed. Section 4 contains a list with personal characteristics and strategies having emerged out of different studies. These characteristics might help second language learners to gain more success in their goal to reach the status of native speakers. This of course can also be useful for language teachers who want to support their learners. Section 5 provides a short conclusion.
2. The Critical Period Hypothesis
Regarding the physical and psychological development of children, research knows several areas for which there exist specific time spans during which certain competences have to be acquired. Otherwise the children would suffer from severe difficulties to develop such competences at an older age or would even fail to develop them at all.
Given that the human brain ends to functionalize and specialize itself at the age of puberty, linguists have argued that there must also exist a critical period for language acquisition (Crystal 2003: 118).
Biologically, language acquisition is located in the left hemisphere of the brain (Yule 2006: 165). The process in which the brain specializes in two hemispheres is also called `lateralization`. Beginning with the early childhood after birth and lasting until puberty, the brain is said to be perfectly open to learn the mother tongue. This time-span is also known as the `critical period`. The existence of the critical period is well documented with research on children who had not had the chance to acquire language in the named time-span out of many reasons like accidents, abuse or else and showed severe difficulties in catching up afterwards. (Yule 2006: 166).
Lenneberg (1967, quoted in: Johnson and Newport 2010: 240) was the first to formulate the “Critical Period Hypothesis” for first language acquisition on the basis of biology and neurology mentioned above. He stated that learning the mother tongue only occurs at childhood and supported this claim by considering a neurologically founded change in brain plasticity according to age. (Johnson and Newport 2010: 241-242).
A wide range of studies have tried to validate or falsify the Critical Period Hypothesis since then. To name just one, Newport and Supalla (Newport and Supalla 1987) tested the hypothesis on deaf people and their mother tongue, which was the American Sign Language. The study provided proof of a certain “decline over age in the ability to acquire a first language”, but it was a “continuous linear decline in ability, instead of a sudden drop-off at puberty” (Johnson and Newport 2010: 242). In addition to that, the study showed that “while the postpubescent learners did not reach as high a level of proficiency as … early learners, language did not become totally unlearnable for them” (Johnson and Newport 2010: 243).
Until now, the Critical Period Hypothesis “has proved to be extremely difficult to test and remains controversial”, as Crystal (2003: 118) puts it