User:Aapplegate22/Individual variation in second-language acquisition

Age Effects in Second-Language Acquisition
It is fairly undisputed that child learners of a second language have an advantage over adult learners. What remains an area of intense discussion is how to characterize this age effect, and what is the underlying cause.

Critical Period
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 popularized by Eric Lenneberg in 1967 for L1 acquisition, but considerable interest now surrounds age effects on second-language acquisition (SLA). 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 recognized that certain aspects of SLA may be affected by age, though others remain intact.

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.