Critical Period Hypothesis

The critical period hypothesis is the subject of a long-standing debate in linguistics and language acquisition over the extent to which the ability to acquire language is biologically linked to age. The hypothesis claims that there is an ideal "window" of time to acquire language in a linguistically rich environment, after which further language acquisition becomes much more difficult and effortful.

The critical period hypothesis states that the first few years of life is the crucial time in which an individual can acquire a first language if presented with adequate stimuli. If language input doesn't occur until after this time, the individual will never achieve a full command of language—especially grammatical systems.

The evidence for such a period is limited, and support stems largely from theoretical arguments and analogies to other critical periods in biology such as visual development, but nonetheless is widely accepted. The nature of this phenomenon, however, has been one of the most fiercely debated issues in psycholinguistics and cognitive science in general for decades. Some writers have suggested a "sensitive" or "optimal" period rather than a critical one; others dispute the causes (physical maturation, cognitive factors). The duration of the period also varies greatly in different accounts. In second-language acquisition, the strongest evidence for the critical period hypothesis is in the study of accent, where most older learners do not reach a native-like level. However, under certain conditions, native-like accent has been observed, suggesting that accent is affected by multiple factors, such as identity and motivation, rather than a critical period biological constraint (Moyer, 1999; Bongaerts et al., 1995; Young-Scholten, 2002).

Read more about Critical Period Hypothesis:  History, Second-language Acquisition, Experimental and Observational Studies

Famous quotes containing the words critical, period and/or hypothesis:

    Probably more than youngsters at any age, early adolescents expect the adults they care about to demonstrate the virtues they want demonstrated. They also tend to expect adults they admire to be absolutely perfect. When adults disappoint them, they can be critical and intolerant.
    —The Lions Clubs International and the Quest Nation. The Surprising Years, I, ch.4 (1985)

    Words convey the mental treasures of one period to the generations that follow; and laden with this, their precious freight, they sail safely across gulfs of time in which empires have suffered shipwreck and the languages of common life have sunk into oblivion.
    —Anonymous. Quoted in Richard Chevenix Trench, On the Study of Words, lecture 1 (1858)

    On pragmatistic principles, if the hypothesis of God works satisfactorily in the widest sense of the word, it is true.
    William James (1842–1910)