ABSTRACT
The idea that children have a special talent for languages that is rarely, if ever, available to older learners is one that has much popular support. Among second language researchers, however, the related hypothesis of a maturationally delimited critical period for language acquisition has been a constant source of controversy. Not everyone accepts the view that young children have an inborn advantage over older learners, and even among those who take this position, debate continues as to what the causes of this advantage are, what the relevant age limits are, what aspects of language development it applies to, and what sort of empirical data provide a crucial test of the critical period hypothesis. In this chapter, we review relevant research findings and consider various proposed explanations of age-related differences in (second) language acquisition. We argue that, despite a number of unresolved problems and even some apparent counterevidence, the critical period concept, as it has evolved, continues to have considerable heuristic value in investigating the language development of learners whose exposure to a new language begins at different ages.
