Individual variation in second-language acquisition

There are two definitions that help explain individual difference variables. The first is predictive, language aptitude is related to a set of cognitive abilities. These cognitive abilities allow one to predict how well an individual can learn a foreign language. These abilities change under limited time and circumstances. The second definition is interactional. It views language aptitude as comprehension abilities during second language learning. Aptitude is or can be subject to change according to an environment. It highlights that no specific instruction works for all second language learners. Therefore, in order for an individual to grasp a second language, there must be an adaption. Where the learner’s abilities can flourish under different learning conditions.[1]

A meta-analysis brought to light that the importance of aptitude is an overestimate when it comes to grammatical capability. In specific conditions, language aptitude is a conscious construct which affects learning results. Language aptitude can be useful in predicting the beginning stages of second language learning, when it comes to grammatical competence, but it is not a reliable way to learning stages.[1]

Tests of language aptitude have proven extremely effective in predicting which learners will be successful in learning.[2] However, considerable controversy remains about whether language aptitude is properly regarded as a unitary concept, an organic property of the brain, or as a complex of factors including motivation and short-term memory. Research has generally shown that language aptitude is quite distinct from general aptitude or intelligence, as measured by various tests, and is itself fairly consistently measurable by different tests.

Language aptitude research is often criticized for being irrelevant to the problems of language learners, who must attempt to learn a language regardless of whether they are gifted for the task or not. This claim is reinforced by research findings that aptitude is largely unchangeable. In addition, traditional language aptitude measures such as the Modern Language Aptitude Test strongly favor decontextualized knowledge of the sort used in taking tests, rather than the sort used in conversation. For this reason little research is carried out on aptitude today. However, operators of selective language programs such as the United States Defense Language Institute continue to use language aptitude testing as part of applicant screening.

How children acquire native language (L1) and the relevance of this to foreign language (L2) learning has long been debated. Although evidence for L2 learning ability declining with age is controversial, a common notion is that children learn L2s easily and older learners rarely achieve fluency. This assumption stems from ‘critical period’ (CP) ideas. A CP was popularised by Eric Lenneberg in 1967 for L1 acquisition, but considerable interest now surrounds age effects on second-language acquisition (SLA).[3] SLA theories explain learning processes and suggest causal factors for a possible CP for SLA, mainly attempting to explain apparent differences in language aptitudes of children and adults by distinct learning routes, and clarifying them through psychological mechanisms. Research explores these ideas and hypotheses, but results are varied: some demonstrate pre-pubescent children acquire language easily, and some that older learners have the advantage, and yet others focus on existence of a CP for SLA. Recent studies have recognised that certain aspects of SLA may be affected by age, though others remain intact.[4]

In terms of specific ages, Steven Pinker and colleagues conducted a large-scale internet study aimed at measuring individual’s age, English proficiency, and amount of time spent practicing English. The findings suggest that the ability to learn a new language with fluency declines after age 18 and must begin by age 10. There are three main factors why our ability to acquire a new language declines after the age of 18. First, significant social changes usually occur at the age of 18. For example, during this period of time individuals may be heading off to college or entering the workforce. As a result, less time is dedicated towards learning a new language. Secondly, an individual’s primary language may impede the development of a newer language. The grammatical rules of our first language become more readily available in our minds as we are exposed to our first language in larger quantities. Lastly, our brains are still developing. In this case, learning becomes more difficult because the brain is undergoing significant changes during our late teenage years and early-20s.

The effective use of strategies has been shown to be critical to successful language learning, so much so that Canale and Swain (1980) included "strategic competence" among the four components of communicative competence.[5] Research here has also shown significant pedagogical effects. This has given rise to "strategies-based instruction."

Strategies are commonly divided into learning strategies and communicative strategies, although there are other ways of categorizing them. Learning strategies are techniques used to improve learning, such as mnemonics or using a dictionary. Learners (and native speakers) use communicative strategies to get meaning across even when they lack access to the correct language: for example, by using pro-forms like "thing", or non-spoken means such as mime. Communicative strategies may not have any direct bearing on learning, and some strategies such as avoidance (not using a form with which one is uncomfortable) may actually hinder learning.

Children use their own strategies of cross reference to learn second languages. A longitudinal study investigated preschool children in an environment where they were exposed to English as a second language.[6] What was noted was that the children applied the knowledge from their first language, using patterns to develop their phonology.[6] It was seen that mere immersion and rehearsal was an effective way for the children to increase their proficiency of their second language.

Learners from different cultures use strategies in different ways,[7] as a research tradition led by Rebecca Oxford has demonstrated. Related to this are differences in strategy use between male and female learners. Numerous studies have shown that female learners typically use strategies more widely and intensively than males; this may be related to the statistical advantage which female learners enjoy in language learning.

Different learning strategies have been evaluated and tested to determine the efficacy of their methods.

A strategy that was found effective with English speaking Chinese learners was the use of a virtual environment. A virtual environment consists of a digital world in which a person may experience whatever is programmed. A virtual environment was created using the online virtual world known as Second Life, where the users could interact with objects, learning the words and sounds simultaneously.[8] This learning strategy was found to be significantly more effective than traditional methods of displaying solely an image and sound.[8] A similar study was done immersing Chinese learners in a virtual environment and found visualization of the objects increased the learning proficiency and scores on the proficiency test.[9] The results of the two studies suggest an advantage when using a virtual environment juxtaposed to traditional methods among Chinese learners.

Affective factors relate to the learner's emotional state and attitude toward the target language. Research on affect in language learning is still strongly influenced by Bloom's taxonomy, which describes the affective levels of receiving, responding, valuing, organization, and self-characterization through one's value system. It has also been informed in recent years by research in neurobiology and neurolinguistics. A research study conducted by Ni (2012), was interested in the role that affective factors played in second-language acquisition (SLA).[10]Additionally, she wanted to know how to apply this knowledge to the context of an educational setting. For example, many instructors want to create lessons for students that facilitate the process of learning a new foreign language. The study Ni (2012) conducted sought to find what important skills students could implement in their SLA pursuits.[10] A 10-item questionnaire was administered to 50 students enrolled in the Foreign Language Department at Heze University in China. The questions collected data on participants’ English fluency, affective factors influence in their SLA, and the preferred method of feedback from their instructor. The main findings displayed how affective factors (e.g. motivation, self-confidence, and anxiety) may advance the acquisition of English as a second language.[10] By using this knowledge, teachers can strengthen their students’ emotional states and create a more welcoming class environment. In doing so, students may be able to acquire a second language more effectively.