The Implications of the Critical Period in Second Language Acquisition
Abstract: This thesis focuses on the discussion of the Critical Period for Second Language
Acquisition (SLA), and illustrates the role of the Critical Period in Second Language Acquisition. With the help of the analysis of various views and some typical examples of practice, the thesis discusses the effects of age and its reasons in SLA, points out the optimal age of learning English for children whose native language is Chinese.
Key Words: implication, language acquisition, lateralization
I. Introduction
With the development of international exchange and co-operation, one may get in touch with more than one language. At lease the can meet with another one besides his mother tongue. Experts have been doing research on how to acquire second language. There are plenty of theories on language acquisition and most of them are put into practice. But the Critical Period is the most important one in any language acquisition. Based on the role of the Critical Period in second language acquisition, this article discusses the optimal age of learning English for children in China.
II. The Role of Age in Second Language Acquisition (SLA)
Second language Acquisition is a complex process, involving many interrelated factors. Because of individual differences in the way learners learn a second language and the way they use second language knowledge, it’s probably accurate to say that no two learners learn a second language in exactly the same way. The learner factors that can affect the course of development are potentially infinite and very different to classify in a reliable manner. The research of SLA, however, has examined some general factors that contribute to individual learner differences in some depth, and age is one of these factors.
2.1 The Effects of Age
First, it’s very necessary to separate the effects of age on the route of SLA from the effects on the rate of SLA. Most of the investigations that have studied the role of age have been related to the latter. That is to say, experts have studied the level of relation between length of learning period and measures of proficiency achieved.
The useful evidence shows that age does not affect the route of acquisition. "Bailey et al. (1974) investigated order in which adults acquire the same set of grammatical morphemes studied by Dulay and Burt." (Ellis, 1985). They found an order very similar to that found in the morpheme studies of children. And Fathman’s study suggests that children (11 to 15 years) know better in morphology and syntax than those (6 to 10years). However, the method used in both of these investigations was to make accuracy and acquisition orders equal. So it is methodologically doubtful about the effectiveness of the results.
The age of the learner strongly affected the rate of SLA. If different learners at different ages are divided according to the amount of time they have spent on second language, it is the older who reaches higher levels of proficiency. However, this statement needs to be expounded in two important ways. First, as the study of Snow and Hoefnagel-Hohle(1978) shows , adolescents may progress most rapidly. The second discussion to the statement relates to the aspect of language that is being investigated. Here, Snow’s study is also relevant. They noticed that age was a factor only when it came to morphology and syntax. The differences on pronunciation were very small. But, where pronunciation is discussed, the common belief that children are superior was not argued.
Once the success of SLA is concerned, it’s not surprising to find that the longer the spending to the second language is, the more native-like second language proficiency becomes.
With the period of time, the length of the learning periods begins to be outweighted by the effects of the learner’s age. At least, it’s on listening and reading tests, but less clearly so on speaking and writing tests. This observation, which the effects of length of the learning period are most strongly felt in productive rather than receptive skill, is lent support by Ekstrand (1975).(Ellis,1985)
These results seem confusing and contradictory. But if route, rate and success are regarded as separated, if the differential effects of ages are suitably divided into pronunciation, vocabulary and grammar, and if the beginning age is not confused with the length of years’ exposure to the second language, there is a brief summary:
1) Beginning age does not affect the route of SLA distinctly. These are not the results of age though there may be different orders in the language acquisition. It’s possible to succeed in starting learning second language at any age.
2) Beginning age affects the rate of SLA distinctly. Where grammar, meaning and vocabulary are concerned, adolescent learners do better than either children or adults, as the length of learning period is fixed.
3) The length of years’ exposure affects the level of success of SLA. And the length of years’ exposure is closely related to the achievement of the learners’ capacities of overall communication, but the beginning age determines the levels of accuracy achieved, particularly in pronunciation.
2.2 Reasons for the Effects of Age
Various interconnected reasons have been offered to account for the effects of age on SLA. The first group contains reasons that are concerned with the development of the human brain. According to ’the Critical Period Hypothesis’, the optimal age for language acquisition is the first ten years of life. However, this plasticity begins to disappear with the onset of puberty. It’s suggested that the result is the lateralization of the language function in the left hemispheres of the brain. That’s to say, for most people, the neurological capacity for understanding and producing language is slowly concentrated in the left hemispheres.(Ellis,1985)
So the neurological basis of language was different in adults and children. In fact, Lenneberg assumed that it is easier for children in language acquisition. But it is just partially correct, because only where pronunciation is concerned is an early beginning an advantage, and even only in the success of SLA, not rate of acquisition. As previous parts have discussed, the process of language functions is a gradual one, carrying on over many years. Older second language learners have the left hemispheres of the brains available for language processing. In addition, their brains in general are less flexible. This makes it difficult for them to absorb new ideas and information. They are thus unable ever to reach the same overall lever of second language proficiency as those who begin to learn the second language during the critical period.
A second set of reasons involves difference resulting from the differing stages of cognitive development reached by child and adult learners. One obvious difference between young children and the adolescents or adults is that the latter’s ability of comprehending language is a formal system. Young children are not so liable to respond to language as form, and language is just a tool for expressing meaning for them. At the stage of cognitive development they relate to second language according to what it can do, not according to what it is. Their brains are not ready to begin the formal study of the language system. In contrast, older learners being cognitively more mature can learn language through studying the linguistic rules consciously, which they also can apply whenever they like. This difference explains the initially faster development of adults’ linguistic competence. Later though, older learners often find it difficult to move no to do things with the language knowledge they have. In Rosarskey’s (Ellis, 1985) view, the young children don’t know that they are acquiring the language, furthermore, they have not developed social attitudes towards the use of one language as opposed to another. But adults can’t learn a second language automatically and naturally.
The third group of reasons focuses on social-psychological factors. Brown (1980b) (Ellis, 1985) suggest that SLA is connected with stages of acculturation. Young children seem social-culturally resilient, because they are less culture-bound than adults. But Neufeld (1928) offers a more convincing reason of how social-psychological factors are related to age difference. He divides language into "primary" levels which include a large functionally vocabulary, basic mastery of pronunciation and grammatical rules, and "secondary" levels --- the ability to handle complex grammatical structures and different language styles (Ellis, 1985). However, young children are more likely to achieve secondary levels than adults because they are much more strongly motivated by the acceptable need of their peer groups.
So, Neufeld’s theory, added the previous two factors, can expound all the known facts about age differences in SLA.
2.3 The Insights
First, the critical period is an objective reality, though there are some disagreements on the concrete ages of the critical period or lateralized period from 2 to 13 years. The critical period of first language acquisition is more distinct than that of SLA, so it’s important and necessary to catch up the key period to achieve and teach greatly more.
Second, the critical period of SLA is not as important as that of first language acquisition. There is strong plasticity during the development of individuals’ psychology and behavior. When young children acquired their mother tongue, they can learn second language at any time. There will be some efforts that whether young children, adolescents, or adults begin to learn the second language, only with hard studying and correct methods.
Third, children (6 to 10 years) can do better in pronunciation than adolescents (12 to 15 years) and adults (over 15 years). Those adolescents can do best in both morphology and syntax among children and adults.
Fourth, English teaching should draw on the different age characteristics of different individuals in order to get more achievements.
Last, the length of years’ exposure to learn second language strongly affects the success of SLA. Particularly, there are close relations between the length of learning and the achievements of ability of communication. Generally, the long one spends in learning, the more be achieves.
III. The Optimal Age of Learning English for Children in China
With the development of national economy, and the policy of open-to-world, English learning is becoming more and more seriously attentioned to around China. Some primary schools have set up English lessons. Then, when is the best for children to begin second language learning? As to this question, foreign scholars have different view. The school of reason thinks that the critical period of second language learning is 14 or 15. Hamley’s (see王斌华，1996：P28) view points out the most idealistic age of second language learning is about 12. British linguist L.G. Alexander thinks that the age of 8 or 9 is the optimal age to start second language learning (see王斌华，1996：P28).
According to children’s competence of learning English the childhood can be divided into two periods --- 4 or 6 and 7 to 12. From the view of children’s psychological development, children aged 4 to 6 are in the period when their abilities of perception, concentration and memorization are developing comparatively rapidly and their power of consideration and imagination begins to sprout. The rapid development of language behavior is the most vivid character of that period. They continuously absorb and use language in order to develop and improve their own language. For example, they ask what this is or that is, ask adults to tell stories to them and talk with their companions without stop. Frequent use of language pushes forward the growth of children’s left hemisphere of brain. Due to the task division of the left and right hemispheres, the growth of the left hemispheres urges the development of children’s language competence in return, but suppresses the growth of the right hemisphere. The imbalance of the growth of these two hemispheres results in the imbalance of the development of children’s thinking. In this period, children’s concrete thinking systems are especially powerful while the abstract thinking system has not established. This psychological phenomenon determines their sense of object when they are perceiving objects and learning languages. For instance, when teaching children English, the teacher presents them a picture of horse and teaches them to say ’a horse’, or presents a picture of hen and teaches them ’a hen’. Then, they can associate the voice of /hɔ:s/ to a horse or /hen/ to a hen after they are taught like that for several times. However, if the teacher writes down ’horse’ and ‘hen’, teaches them to read and tell them ’horse’ is a horse and ’hen’ is a hen, it will be difficult for children to recognize such easy words as ’horse’ and ’hen’ regardless of the teacher’s great efforts. The reason is that alphabetical language does not resemble the forms of object. During the process of memorizing alphabetical language, children’s concrete thinking ability has not been fully applied and exerted. For the children whose nation language is Chinese, the alphabetical language appears abstract. Children’s (4 to 6 years) abstract thinking has been put off because of the slow growth of the right hemisphere of brain. So it’s inevitable to limit their abilities of learning the abstract alphabetical language.
Children aged 4 to 6, in one hand, have many advantages in language learning such as strong imitation ability, memorizing ability (especially unconscious memorizing ability) and acceptance ability, because native language in their brains has not been systematized and sorted out, and has not a fixed model. The exclusive ability in second language learning is weaker in young children then in older children and adults. Besides, their brains are in the period of growing when new brain cells seem pieces of ’blank paper’ where you can draw any ’picture’. Therefore, they possess great plasticity. In the other hand, their articulatory organs are not physiologically sane, especially oral cavity muscles and teeth. What’s more, children in this period are so eager to move that they are almost impossible to settle down to study for a long time as older children and adults do. Because of the limitation of age, they do not possess the ability of studying by themselves and have not a definite aim of learning. So their English teaching is not active and conscious but passive and unconscious.
In one word, children in the age period of 4 to 6 should learn English not in way of teaching and studying in the classroom but in the way of combining ’learning’ with ’acquisition’. Here are some examples, such as teaching a child to learn English, when he is four. One year later, the child had been able to take short conversations in English, call names of objects, persons, animals and plants around him in English, count the numbers in English, recite the children’s ballads in English, sing many children’s English songs, make short speeches in English according to pictures and make reactions to adults’ English directions. For instance, if one said to him ’Go to wash your hands.’ before dinner, he knew that he was told to wash his hands. If one said to him ’Go to bed’ at night and he did not want to sleep that time, he would make bargain with adults after hearing that. When a pear and an apple were in front of him, and one asked him ’Do you want a pear or an apple?’, he would answer ’an apple’ according to his own favorite. Thus those children (4 to 6 years) have great potentiality in learning oral English under the method of combining learning with acquisition if condition permits that.
Let’s see the condition of children in the age of 7 to 12. Children’s brains in that period of age are developing rapidly. As far as some experts concerned, weight of children’s brain in twelve have reached the level of adults, and the half time of brains’ whole development lies between 7 and 12. The rapid development of children’s brain pushes forward their cognitive ability with a large step. At the moment, the development of the left hemispheres and right ones gradually grows to balance day by day. Children’s thinking system also changes from the simple concrete thinking into the combination of concrete thinking and abstract thinking. As to the aspect of concentration and memorizing ability, they are changed from unconsciousness to consciousness. Besides, children in this period of age get certain power of self-restraint. Take an instance, they will not optionally take and leave their seats during class time. They can settle to study for a comparatively long time. Furthermore they have had perceptual knowledge about alphabetic writing. The study and frequent use of Chinese phonetic alphabets provide large convenience for them to recognize and memorize English words. It’s easy to find that children at the age of 7 to 12 memorize and spell English words far more rapidly than the adults who seldom meet phonetic alphabets during the process of teaching them. Most of the words can be directly spelt by them as they conform to the spelling rules. Based on the phonetic alphabets, English handwriting is no longer a burden to them.
So children in this period of age, besides that they have the advantages of the last period (such as strong ability of imitation, memorizing and plasticity), are more mature than children in the last period in the aspect of either psychology or physiology. They have had a little idea about the aim of English learning (They certainly should be directed by their teachers and parents.) and have possessed learning competence. What’s more, they have had certain competence of analyzing and integrating, which provides them condition for English syntactic rules and grammar learning.
As a result, the optimal age for children whose native language is Chinese to start English earning should be 7 to 12, because children at that age have obtained not only the ability of learning oral English but also some primary ability of learning written English.
Bibliography
1. Ellis, Rod. The Study of Second Language Acquisition. New York: Oxford University Press, 1985.
2. Klein, Wolgang. Second Language Acquisition. Cambridge: Cambridge University Press, 1986.
3. Brown, H.Donglas. Principle of Language Learning and Teaching. 2nd ed. N.J.: Prentico Hall,1987.
4. Yin Li Min. "Motivation in Second Language Acquisition. Teaching English in China". The Cultural and Education Section of the British Embassy. ELT Newsletter 22, May 1991.
5. 章兼中，俞红珍，《英语教育心理学》，警官教育出版社，1998。
6. 王斌华，《中小学英语教学与研究》，华东师范大学出版社，1996，第5期28-30页。
