The Studies Challenge a Decades-Old Hypothesis on Language Acquisition ~ Section 2

The following discussion addresses the disproof corresponding to the second of the six aspects of the perquisites for CPH to become a theory.

2. In support of the hypothesis on the critical period, there must be a clear and fixed critical period in the course of individual development.

Lenneberg (1967) found that patients with aphasia showed different degrees of recovery, and all these occurred before puberty. So he inferred that a critical period exists from infancy to puberty.

Johnson and Newport (1989) did not think that a critical period would occur that late. In their research, only people who migrated to the U.S. at the age of 3–7 could show language ability similar to those using the mother tongue. After 7 years old, the ability would begin to decline, showing that the age of 7 is the critical period.

Long (1990) used pronunciation as an experimental indicator for the study. His study showed that the ability to learn a second language declined at approximately 6 years old; therefore the critical period occurred before that.

There are researchers who considered the age of 10 (Curtiss, 1980) or before the age of 12 (Scovel, 1969) as the critical period.

So the exact age for the critical period is still controversial. From the above studies, we can see that even though there is a critical period phenomenon for the learning of a second language, there is no unanimous view as to the time of the critical period.

In fact, the critical periods obtained with the different measuring methods were different (Rosenzweig, 2003). Based on the prerequisite of CPH, there must exist a clear and fixed time point. However, the pieces of evidence obtained did not support the precise point in time, hence the hypothesis for the critical period is dubious (Hakuta et al., 2003).

References

Curtiss, S. (1980). The critical period and feral children. Cognitive Linguistics, 2, 21–36.

Hakuta, K., Bialystok, E. & Wiley, E. (2003). Critical evidence: a test of the critical period hypothesis for second language acquisition. Psychological Sciences, 14, 31–38.

Johnson, J.S. & Newport, E.L. (1991). Critical period effects on universal properties of language: the status of subjacency in the acquisition of a second language. Cognition, 39, 215–258.

Lenneberg, E.H. (1967). The Biological foundations of language. New York: John Wiley & Sons.

Long, M. (1990). Maturational constraints on language development. Studies in Second LanguageAcquisition, 12, 251–285.

Rosenzweig, M.R. (2003). Effects of differential experience on the brain and behavior. Developmental Neuropsychology, 24, 523–540.

Scovel, T. (1969). Foreign accents, language acquisition, and cerebral dominance. Language Learning, 19, 245–254.

Originally published at http://poeticmindfulness.wordpress.com on October 1, 2020.