Individual differences <ul><li>This area studies the ways in which individual people differ in their behavior. </li></ul><ul><li>Each person has an individual profile of characteristics, abilities and challenges that result from learning and development. </li></ul>
AGE Younger L2 learner generally does better than older learners. Critical Period Hypothesis There is a fixed span of years during which language learning can take place naturally and effortlessly, and after which it is not possible to be completely successful. Widely Held Lay Belief
Penfield and Roberts (1959), Optimum period for language acquisition falls within the first ten years of life, when the brain retains its plasticity. Initially, this period was equated with the period taken for lateralization of the language function to the left side of the brain to be completed. Work on children and adults who had experienced brain injuries or operations indicated that damage to the left hemisphere caused few speech disorders and was rapidly repaired in the case of children but not adults (Lenneberg 1967).
Reason for the lack of consensus on the age issue Difficulty of comparing the results of studies Methods Performance Measures
Methods Longitudinal Cross Sectional Experimental Groups of learners Groups of learners 1. Same Starting Time Snow, Hoefnagel, Hohle (1978) 2. Different Starting times Burstall (1975) 1 Individuals Began L2 2. Number of Years Oyama (1976) Investigates the Effects of attempts to teach learners varying in age specific features of an L2. Neufeld (1978)
Performance Measures The studies have also varied in how they have measured learning. Performance measures based on samples of planned or unplanned language use have been used. Grammaticality judgments of learners of different ages have been examined. (Coppieters 1987 ) Native speakers have been asked to rate the performance of mixed groups of learners and native speakers in terms of how native their use of the language is. (Scovel 1981)
The result obtained by these studies fails to agree. As Larsen Freeman and Long (1991) The age issue remains an important one 1. For Theory building in SLA Research 2. For Educational policy making 3. For Language pedagogy
The younger learner do better that older learners The case for an early start in foreign language education is strengthened . Children learn in different ways to adults Language teachers will need to identify different approaches and techniques to suit the two kinds to learners.
In order to untangle the research results, it is helpful to consider a number of separate but related questions. <ul><li>What effect does age have on the rate of </li></ul><ul><li>L2 learning? </li></ul><ul><li>2. What effect does age have on learner’s </li></ul><ul><li>ability to achieve native speaker’s </li></ul><ul><li>level of proficiency? </li></ul><ul><li>3. What effect does age have on learner’s </li></ul><ul><li>levels of L2 achievement </li></ul><ul><li>(in those learners who do not </li></ul><ul><li>reach native speaker proficiency)? </li></ul><ul><li>What affect does age have on the process </li></ul><ul><li>Of L2 learning? </li></ul>
Effects of age according to learning context Naturalistic Instructed learning context
1. The effects of age on rate of second language learning. Krashen, Long, and Scarcella (1979) conclude that (1) adults are superior to children in rate of acquisitions (2) older children learn more rapidly than younger children. The study most often cited in support of these conclusions is Snow and Heofnaggle-Hohle (1978).
Grammar Syntax and Morphology Pronunciation Children GOOD Adolescents BETTER Adults BEST Children BEST Adults GOOD Adolescents BETTER
Adults outperform children in the short term. Oslen and Samuels (1973) Children outperform adults, This research supported to Krashen, Long and Scarcellas’. Cochrani (1980) EXPERIMENTAL STUDIES Controversy
The effect of age on the acquisition of native speaker proficiency. Effect of age on the achievement of native speaker level of proficiency is controversial point. .Comparisons have been made with the critical period hypothesis.
Different studies done on the issue of native speaker level of proficiency <ul><li>Study1-Neufeld (1978) </li></ul><ul><li>This study is often cited by the people who want to refute the critical period hypothesis. </li></ul><ul><li>20 adult native English speakers were given 18 hours intensive instruction in the pronunciation of Chinese and Japanese. </li></ul><ul><li>To test the native ness of their pronunciation, learners were given an imitation test and their utterances were judged on a five point scale( from unmistakably native to heavily accented) by the native speakers of the two languages. </li></ul><ul><li>9 subjects were rated as native for Japanese and 8 were judged native for Chinese. </li></ul><ul><li>As a result this theory suggested that under right conditions, adults can achieve native ability in pronunciation( the most difficult area for the adults) </li></ul>
Criticism on Neufeld’s study <ul><li>Neufeld’s studies are strongly criticized by the supporters of the critical period hypothesis. </li></ul><ul><li>Long(1990) argued that his studies are doubtful because </li></ul><ul><li>A-His subjects were all elite. </li></ul><ul><li>B-The imitation test produced a rehearsed data, not a natural one. </li></ul><ul><li>C-The instruction given to the raters predisposed them to think that some of the subjects were native speakers. </li></ul><ul><li>Result of the study was however not refuted by this very critic that it is possible for adults to achieve native speakers level of proficiency in an L2. </li></ul>
Sudy2-Copieters(1987) <ul><li>21 highly proficient speakers of French and 20 native speakers were judged on grammaticality judgment test. </li></ul><ul><li>Result of the research was that it was not possible to distinguish b/w the two groups by the mistakes they made. (lexis, grammatical construction) And 6 subjects had no traces of foreign accent. </li></ul><ul><li>Despite the native like performance their grammatical competence was different. </li></ul>
Criticism on Copieter’studies <ul><li>Coppieters did not include a group of learners who had started to learn L2 French as children thus we can not be sure that the results he obtained reflect age as opposed to some other factor. </li></ul>
Study-3 Birdsong(1992) <ul><li>Birdsong administered a grammaticality judgment test. to 20 English speaking learners of L2 French. </li></ul><ul><li>This study was actually motivated by Long’s(1990) challenge to investigate whether the very best learners actually have the native like competence. </li></ul><ul><li>Contrary to Coppieters Birdsong found no differences in the judgment of native and non native speakers. </li></ul><ul><li>Birdsong could not find any difference in the think aloud data. </li></ul><ul><li>This study suggested that some of the learners who start learning L2 after puberty period achieve a level of competence indistinguishable from that of native speakers. </li></ul>
Study-4 Thompson(1991) <ul><li>Thompson study was to investigate the claim of critical period hypothesis that whether learners who start learning L2 as young children and enjoy favorable learning conditions succeed in reaching native level of proficiency. </li></ul><ul><li>He studied foreign accents in Russian immigrants in the USA. </li></ul><ul><li>He came to know that learners arriving before they were ten years old, had more English like accent than others. </li></ul>
. <ul><li>Two subjects who came to USA at an age of 4 were rated as having a slight accent. Thompson called it a problem of critical period hypothesis. It is called interlingual identification. </li></ul><ul><li>L1 maintenance and learners wish not to sound like native can be the two factors of it. </li></ul>
Study-5 Scovel(1981) <ul><li>A way to assess native level of proficiency in an L2 learner is to see whether they are able to recognize spoken or written accents like native speakers. </li></ul><ul><li>Scovel asked four groups of subjects to rate speech samples and written pieces. </li></ul><ul><li>He found that very advanced learners lack some of the linguistic abilities of the native speakers. </li></ul>
. <ul><li>To sum up about the experimental studies done that have investigated the effects of age on native speakers level of proficiency we can say that these studies have produced mixed results. </li></ul><ul><li>Birdsong’s designed study would suggest that some learners achieve native speaker’s level of grammatical knowledge. </li></ul><ul><li>Thompson study show that starting early is no guaranty that native speaker abilities will be achieved even in most favorable situations. </li></ul>
The Effects of Age on Learner’s Second Language Achievement <ul><li>The majority of L2 learner fail to reach native speaker level of ability. </li></ul><ul><li>Do the learners who begin learning as children reach higher levels of L2 ability than those who starts as adolescents/adults? </li></ul><ul><li>Different studies on foreign language acquisition in the primary school vs secondary school on the levels of attainment. </li></ul>
Researches on Second Language Achievement. <ul><li>Burstal(1975) Conducted Pilot study. </li></ul><ul><li>Secondary school starters outperformed than primary school starters. </li></ul><ul><li>Harley(1986) Research on level of attainment in children in French Bilingual Program in Canada. </li></ul><ul><li>Focus on the learner’s acquisition of the French verb system. </li></ul>
<ul><ul><li>Neither group had acquired full control of the verb system but old students show greater overall control. </li></ul></ul><ul><ul><li>Results from school based studies is not supportive of the claim that children's level of attainment is greater than adolescents/adults. </li></ul></ul><ul><ul><li>Singleton(1989)Formal learning environment do not provide learners with the amount of exposure needed for the age of advantage of young learner to emerge. </li></ul></ul>
Naturalistic Learning Situation <ul><li>Studies of learner in naturalistic learning situations provide the most convincing evidence that younger is better. </li></ul><ul><li>Learners who starts as children achieve a more native-like accent than who starts as adolescents/adults. </li></ul>
<ul><li>Oyama(1976) Investigates on 60 male immigrants, entered in United States. </li></ul><ul><li>Oyama results, very strong effect for ‘age of arrival’ but almost no effect for the ‘number of years’. </li></ul><ul><li>She found that the youngest arrivals performed at the same range as native speaker controls. </li></ul>
<ul><li>The effect of age on pronunciation support the younger-is-better in position. </li></ul><ul><li>Similar results have been obtained for the acquisition of grammar. </li></ul><ul><li>Patkowski(1980;1990) results, learner who entered in United States at the age of 15 were syntactically more proficient than who entered after 15. </li></ul>
<ul><li>Marked difference between scores based on 5 point scale. </li></ul><ul><li>Singleton(1989)writes; </li></ul><ul><li>Concerning the hypothesis that those who begin learning a second language in childhood in the long run generally achieve higher levels of proficiency than those who begin in later life, one can say that there is some good supportive evidence and there is no actual counter evidence. </li></ul>
The Effect of Age on the Process of second Language Acquisition <ul><li>There have been few studies of the effects of age on the process of L2 acquisition. </li></ul><ul><li>The Morpheme Studies: Order of acquisition of a group of English morphemes was the same for children and adults. (Bailey,Madden,Krashen1974) </li></ul>
<ul><li>Transitional Structures: </li></ul><ul><li>studies which have investigated the sequence of acquisition in transitional structures such as negative and interrogative. </li></ul><ul><li>Cancino et al.(1978) Adults go through the same stages of acquisition as children. </li></ul>
<ul><li>Harley’s(1986) investigation of early and late immersion programmes. </li></ul><ul><li>Unmarked French verb forms more accurately than the marked forms. </li></ul><ul><li>Riney(1990) collected data from Vietnamese learners of English. Age has no effect on the final deletion of consonants, it did have a marked effect on epenthesis. </li></ul>
<ul><li>It is premature to conclude that age has no effect on the process of acquisition. </li></ul><ul><li>The research suggest that the effect may be a minimal one in case of grammar, but possibly more significant in the case of pronunciation. </li></ul>
SOME GENERAL CONCLUSIONS. The research that has addressed the age issue is quite enormous. Not surprisingly, commentators have arrived at different conclusions, but despite this some common ground is emerging. 1. Adult learners have an initial advantage where rate of learning is concerned, particularly in grammar. They will eventually be overtaken by child learners who receive enough exposure to the L2. This is less likely to happen in instructional than in naturalistic settings because the critical amount of exposure is usually not available in the former.
2. Only child learners are capable of acquiring a native accent in informal learning contexts. Long (1990a) puts the critical age at 6 years, but Scovel argues that there is no evidence to support this and argues for a pre puberty start. Singleton (1989) points out those children will only acquire a native accent if they receive massive exposure to the L2. However, some children who receive this exposure still do not achieve a native like accent, possibly because they strive to maintain active use of their L1. Adult learners may be able to acquire a native accent with the assistance of instruction, but further research is needed to substantive this claim.
3.Children may be more likely to acquire a native grammatical competence. The critical period for grammar may be later than for pronunciation (around 15 years.) Some adult learners, however, may succeed in acquiring native level of grammatical accuracy in speech and writing and even full linguistic competence, 4. Irrespective of whether native speaker proficiency is achieved, children are more likely to reach higher level of attainment in both pronunciation and grammar than adults.
<ul><li>The process of acquiring and L2 grammar is not substantially affected by age, but that of acquiring pronunciation may be. </li></ul>
Explaining the role of age in second language acquisition These general conclusions provide substantial support for the existence of at least a sensitive period for L2 acquisition. A number of explanations have been advanced to account for the existence of a critical or sensitive period. These have been admirably reviewed in Singleton (1989) and Long (19904, and are summarized in Table.
One of the major points of controversy is whether the differences between child and adult learners are to be explained as primarily the result of environmental factors or of changes in the mental and neurological mechanisms responsible for language learning. Muhlhauser (1986), after an extensive study of the developmental stages of Pidgin languages and their similarities to language acquisition, concludes that adults and children appear to behave very much in the same manner which indicates that ‘activation of certain linguistic developments is dependent on the presence of specific environmental factors, rather than on different cognitive abilities of children and adults’ (198& 265—s). Long, on the other hand, concludes that a neurological explanation is best and proposes the attractive-sounding ‘ mental muscle model’
Long’s ‘mental muscle model’, therefore may not provide a satisfactory explanation where L2 phonology is concerned, but seems to offer a convincing account of why child and adult learners do not differ in the process of acquiring an L2 grammar.
CONCLUSION To conclude, it is not yet possible to reach an> definite decisions on such key issues as whether adults have continued access to a language-specific acquisition device such as Universal Grammar. One tentative conclusion suggested by the research is that the acquisition of phonology (which appears to be particularly sensitive to age) proceeds somewhat differently from the acquisition of grammar (which appears much less sensitive).
There are changes in the neurological structure of the brain at certain ages which affect learner’s abilities to acquire L2 pronunciation and grammar. Various accounts of the nature of these changes have been proposed to account for the loss of plasticity that occurs with age (e.g. lateralization and cerebral maturation). Neurological the language learning capacity of adults is impaired by deterioration in their ability to perceive and segment sound in an L2. Sensory acuity
Adult learner on general inductive learning abilities to learning abilities to learn and L2 while children use their language acquisition device. Cognitive factors Child learners are more strongly motivated to communicate with native speakers and to integrate culturally. Also child learners are less conscious and therefore suffer less from anxiety about communicating in an L2. Affective Motivational factors.
Children store L1 and L2 information separately (i.e. become coordinate bilinguals) adults store L1 and L2 knowledge together (i.e. become compound bilinguals.) Storage of L2 information The language input received by children is superior to that received by adults. However, adults may experience more negotiation of meaning Input