A general theory of second language acquisition needs to account for language acquisition by learners with a variety of characteristics in a variety of contexts. In this chapter we examine some of the theories that have been offered to account for second language developmental progress and final learning outcomes. We will look at how the behaviourist and innatist explanations for first language acquisition that we saw in Chapter 1 have been extended to account for second language acquisition. We will also look at some theories from cognitive psychology that have increasingly informed second language research in recent years. These theories emphasize the way the mind perceives, retains, organizes, and retrieves information. Finally, we will look at sociocultural theory, a perspective that places second language acquisition in a larger social context.
一个通用的第二语言习得理论需要能够解释具有不同特征的学习者在不同情境下的语言习得过程。在本章中，我们将探讨一些用以解释第二语言发展进程和最终学习结果的理论。我们将考察第一章中看到的行为主义和先天主义对第一语言习得的解释是如何被扩展用来解释第二语言习得的。我们还将考察一些近年来日益影响第二语言研究的认知心理学理论。这些理论强调心智感知、保留、组织和提取信息的方式。最后，我们将探讨社会文化理论，这是一种将第二语言习得置于更广阔的社会背景中的视角。
As we saw in Chapter 1, behaviourist theory explained learning in terms of imitation, practice, reinforcement (or feedback on success), and habit formation. Much of the early research within behaviourist theory was done with laboratory animals, but the learning process was hypothesized to be the same for humans.
正如我们在第一章中看到的，行为主义理论通过模仿、练习、强化（或对成功的反馈）和习惯养成来解释学习。行为主义理论的早期研究大多是在实验室动物身上进行的，但该理论假设人类的学习过程与动物相同。
Behaviourism had a powerful influence on second and foreign language teaching, especially in North America, from the 1940s to the 1970s. Nelson Brooks (1960) and Robert Lado (1964) were two proponents of this perspective. Their influence was felt directly in the development of widely used audiolingual teaching materials and in teacher training. Classroom activities emphasized mimicry and memorization, and students learned dialogues and sentence patterns by heart. Because language development was viewed as the formation of habits, it was assumed that a person learning a second language would start off with the habits formed in the first language and that these habits would interfere with the new ones needed for the second language. Thus, behaviourism was often linked to the contrastive analysis hypothesis. However, as we saw in Chapter 2, researchers found that many of the errors learners make are not predictable on the basis of their first language, nor do they always make the errors that would be predicted by a simple comparison of their first and second languages. This discovery led to the rejection of both the contrastive analysis hypothesis and behaviourism, leading to a period during which both the role of the first language and the role of practice in learning a second language received limited attention in both research and pedagogy.
从20世纪40年代到70年代，行为主义对第二语言和外语教学产生了巨大影响，尤其是在北美。纳尔逊·布鲁克斯（Nelson Brooks）（1960）和罗伯特·拉多（Robert Lado）（1964）是这一观点的两位支持者。他们的影响直接体现在广泛使用的“听说法”（audiolingual）教材的开发和教师培训中。课堂活动强调模仿和记忆，学生们要熟记对话和句型。由于语言发展被视为习惯的养成，因此人们假设，学习第二语言的人会从第一语言中形成的习惯开始，而这些习惯会干扰第二语言所需的新习惯。因此，行为主义经常与“对比分析假说”（Contrastive Analysis Hypothesis）相联系。然而，正如我们在第二章中看到的，研究人员发现学习者所犯的许多错误并不能基于他们的第一语言来预测，他们也并不总是犯那些通过简单对比第一语言和第二语言就能预测出来的错误。这一发现导致了对比分析假说和行为主义均被摒弃，并带来了一段时期，在研究和教学中，第一语言的作用和练习在第二语言学习中的作用都很少受到关注。
In Chapter 2, we saw ample evidence that second language learners draw on what they already know-including previously learned languages. However, we also saw that they are sometimes reluctant to transfer certain first language patterns, even when the translation equivalent would be correct. And we saw that first language influence may become more apparent as more is learned about the second language, leading learners to see similarities that they had not perceived at an earlier stage. All this suggests that the influence of the learner’s first language may not simply be a matter of habits, but a more subtle and complex process of identifying points of similarity, weighing the evidence in support of some particular feature, and even reflecting (though not necessarily consciously) about whether a certain feature seems to ‘belong’ in the target language.
在第二章中，我们看到了充分的证据，表明第二语言学习者会利用他们已经知道的知识——包括以前学过的语言。然而，我们也看到，他们有时不愿意迁移某些第一语言模式，即使翻译上对等的表达是正确的。我们还看到，随着对第二语言了解的增多，第一语言的影响可能会变得更加明显，导致学习者看到了他们在早期阶段未曾察觉到的相似之处。所有这些都表明，学习者第一语言的影响可能不仅仅是习惯问题，而是一个更微妙、更复杂的过程，涉及识别相似点、权衡支持某一特定特征的证据，甚至（尽管不一定是有意识地）思考某一特征是否似乎“属于”目标语言。
By the 1970s, many researchers were convinced that behaviourism and the contrastive analysis hypothesis were inadequate explanations for second language acquisition. As we shall see, however, as research on second language acquisition has evolved, the explanations offered by behaviourism and the contrastive analysis hypothesis have been revisited and understood in terms of new learning theories.
到了20世纪70年代，许多研究人员相信，行为主义和对比分析假说不足以解释第二语言习得。然而，正如我们将看到的，随着第二语言习得研究的发展，行为主义和对比分析假说所提供的解释已在新的学习理论框架下被重新审视和理解。
As we saw in Chapter 1, the rejection of behaviourism as an explanation for first language acquisition was partly triggered by Chomsky’s critique of it. Chomsky argued that innate knowledge of the principles of Universal Grammar permits all children to acquire the language of their environment during a critical period of their development. While Chomsky did not make specific claims about the implications of his theory for second language learning, Lydia White (2003) and other linguists have argued that Universal Grammar offers the best perspective from which to understand second language acquisition. Others, for example Robert Bley-Vroman (1990) and Jacquelyn Schachter (1990) have suggested that, although UG may be an appropriate framework for understanding first language acquisition, it does not offer a good explanation for the acquisition of a second language, especially by learners who have passed the critical period. In their view, this means that second language acquisition has to be explained by some other theory, perhaps one of the more general psychological theories described below.
正如我们在第一章中看到的，乔姆斯基（Chomsky）对行为主义的批判在一定程度上引发了人们对行为主义作为第一语言习得解释的摒弃。乔姆斯基认为，儿童正是凭借对“普遍语法”（Universal Grammar）原则的先天认识，才得以在发展的关键期习得他们环境中的语言。虽然乔姆斯基没有具体说明他的理论对第二语言学习的意义，但莉迪亚·怀特（Lydia White）（2003）和其他语言学家认为，普遍语法为理解第二语言习得提供了最佳视角。其他人，例如罗伯特·布莱-弗罗曼（Robert Bley-Vroman）（1990）和杰奎琳·沙赫特（Jacquelyn Schachter）（1990）则提出，尽管普遍语法（UG）可能是理解第一语言习得的合适框架，但它并不能很好地解释第二语言的习得，特别是对那些已经过了关键期的学习者而言。在他们看来，这意味着第二语言习得必须由其他理论来解释，也许是下文描述的更具普遍性的心理学理论之一。