9.2 Factors affecting SLA

　 Second language acquisition is a complex process which involves various factors. The factors can be put into two categories: social factors and learner factors (some scholars prefer the terms external and internal factors). Each category includes a number of factors. This chapter will survey the key factors that affect the outcome of the process.

　 Social contexts strongly influence second language acquisition. The language policy of the government and the attitude of the public sector toward a language other than the mother tongue directly affect the learners of the language. Whether a language is learned is preconditioned by the social recognition of the value of that language in meeting the socio-economic needs of the society. The social demand for personnel able to use a second language is the starting point of and the impetus to second language learning. This has been proved by international and national surveys. For example, the International Association for the Evaluation of Educational Achievement surveyed the outcomes of the learning of English as a second language in ten countries. The co-authors of the report found a direct relation between the proportion of students learning English and the amount of trade of the country with the English-speaking world (Lewis and Massel 1975). In 1975, the Committee on Foreign Languages of Australia Academy of the Humanities reported that from the mid 1960s to the mid 1970s enrolments in Latin, French and other European languages dropped by 58.3%, while enrolments in Asian languages increased rapidly. The enrolments in Japanese rose by 500% in the period, due to the increase of trade between Australia and Japan.

　 With the trend of globalization of the world economy, it is widely accepted among educators and national leaders that proficiency in another language is an indispensable quality of educated people. Educators in many monolingual countries have pointed out that in the present world monolingualism is a serious handicap. The study of at least one other language as a way of increasing the individual's power of communication ought to be an indispensable part of every school curriculum. This international milieu has given rise to an upsurge of second language learning in the last three decades of the twentieth century.

　 Learner factors are many. Researchers have examined individual differences in attempting to answer the question “Why some learners are more successful than others in learning a second language within the same social context?” Different researchers have identified different learner variables as important in influencing learning outcomes. Among the variables the more frequently discussed are motivation, age, and learning strategies.

　 Motivation is unanimously acknowledged by researchers and language teachers as an important factor. Learning is often seen as preconditioned by motivation. A pioneering study in motivation for second language acquisition was reported in Gardener and Lambert (1972). The starting point of their study is this question: how is it that some people learn a second or foreign language so successfully while others find it almost impossible, given the same opportunities to learn? Based on their investigations in Canada they put forward a socio-psychological interpretation of the cause of success or failure. They drew a distinction of instrumental motivation and integrative motivation and suggested that learners who are integratively motivated are more likely to be successful, because they are psychologically prepared to adopt various aspects of the behavior which characterizes members of another linguistic-cultural group, or even eventually to become a member of that group.

　 There have been many studies following Gardener and Lambert's dichotomy of motivation (See Ellis 1994 for a survey). A limitation of Gardener and Lambert's interpretation is that the relation between motivation and success is unidirectional. It can hardly account for the motivation of young children learning a second/foreign language, who may not be truly aware why they have to learn it. In this situation, the dichotomy is found not only theoretically inadequate but also practically not instructive. English teachers in Chinese schools find it hardly effective to motivate their pupils by telling them why they must learn English. Some studies suggest that learners' motivation is strongly affected by their achievement. Savignon (1972) reported that students' desire to learn French increased with gains in French proficiency. Hermann (1980) and Strong (1984) also suggested that it is success that contributes to motivation rather than vice-versa. Even if we acknowledge instrumental or integrative motivation as an initial inner urge of the learner that drives him/her to start to learn, there is indeed a question whether the motivation can be sustained. Then it is logical that the practice based on the assumption that “children learn a second language now, use it later” needs reconsidering. The idea that the learners have a sense of achievement as long as they learn is of vital importance. This kind of motivation may be termed cognitive motivation (also termed resultant motivation by some scholars).

　 Age is another learner factor that has been an issue in second language acquisition research. In the late 1950s and early 1960s age was seen as a factor that determines success. The critical period hypothesis states that there is a period when language acquisition takes place naturally and effectively. It was believed that the optimal age falls within the first ten years. The hypothesis was based on two assumptions: 1) the neurological basis of language in children is different from that in adults; 2) children outperform adults in all aspects of second language acquisition. Whether the former is valid remains an issue, but the validity of the latter has been challenged by later studies.

　 The results of research in the 1970s and 1980s show that age does not change the route of acquisition. It is found that adults acquired a set of grammatical morphemes in an order similar to that of children's acquisition of those morphemes (e.g. the plural -s is acquired earlier than the third person singular -s ). In terms of success, children only do better in pronunciation, but they are outperformed by adolescents and adults in mastering morphology and syntax within the same length of time. These findings suggest that children and adults have their respective advantages and disadvantages. Adults are advantageous in cognitive capabilities. Children are better learners in pronunciation. There have been physical, cognitive and affective explanations for children's better performance in acquiring the phonological system of a second language but it remains inconclusive what accounts for the correlation between age and pronunciation.

　 Learning strategy is still another factor recognized by applied linguists. Learning strategies are the particular approaches or techniques that learners employ to try to learn a second language, especially in solving specific problems they encounter. O’Malley et al. (1985) designed a study to identify the type and frequency of learning strategies used by beginning and intermediate students of English as a second language. They make a distinction between cognitive strategies, such as inferring or guessing meaning from context, and metacognitive strategies, such as directing attention to the learning task, monitoring and evaluating learning.

　 Studies have been conducted to investigate whether learning strategies are correlated with learning outcome. The findings have shown that successful learners use more strategies than unsuccessful learners. Successful learners pay attention to both form and function. They are more active and selective in using strategies. However, the correlation between learning outcome and learning strategy awaits further research. The question remains open: Does successful learning result from appropriate use of strategies or does success in learning enable learners to use strategies appropriately? Is the relation reciprocal between learning outcome and learning strategies?

　 In this section we have surveyed social factors and leaner factors affecting SLA. For groups or individuals all the factors are variables of the process of second language acquisition. They function concurrently in the complex process. To understand the role of one variable researchers have to control others, holding them as constant. But learner factors such as motivation, age, learning strategies (and others such as personality, aptitude, etc) are also mutually related. It is therefore important that language teachers observe their students as a group and as individuals to see what factors should be given special attention.