The Robustness of Critical Period Effects in Second Language Acquisition (2000)
Robert M. DeKeyser (University of Pittsburgh, USA)Studies in Second Language Acquisition, 22(4), pp.499-533
One of the two hypotheses tested in DeKeyser’s study is the Critical Period hypothesis, which states that an individual beyond a particular age lacks the language learning skills a child has (DeKeyser, 2000, p.500). A topic of controversy within the field of linguistics, the Critical Period was conceived by Penfield and Roberts (1959) and later Lenneberg (1967). As there are critical periods in an individuals’ life for brain development, their concept states that there is a particular age range during which a language should be learnt in order to reach a native-like standard. The language learning ability of an individual gradually declines between after puberty, usually around the ages of 16 or 17 (Johnson and Newport, 1989).
A second hypothesis DeKeyser investigated in his study was the Fundamental Difference hypothesis. Popularised after its formulation by Bley-Vroman (1988), this hypothesis details that an adult is incapable of depending upon the innate mechanisms for language acquisition available to them as a child. Children can learn their native language without ease, though this is not the case for most adults. An adult therefore must form alternative problem-solving mechanisms in order to successfully acquire an additional language (DeKeyser, 2000, p.500-501).
1) Theoretical Foundation
The results from the study confirmed a strong negative correlation between the age of acquisition of English and the score on the grammaticality judgement test. The tests also showed that aptitude plays a pivotal role in an adult language learner, as analytical and problem-solving skills are key to successfully acquire an additional language successfully. As predicted, varying structures showed differing degrees of correlation with age ofarrival. There are four principal conclusions which can be drawn from DeKeyser (2000).1) Learners with high verbal ability are exempt from thecritical period effect as they have the ability to use explicit learningmechanisms in order to successfully acquire an additional language.2) The fundamental difference hypothesis is confirmed as noadult reached a native level without relying upon such explicit languagelearning mechanisms3) Aptitude is a predictor of ultimate attainment in L2 and theage an individual arrives in the US determines their verbal ability4) There is a critical period – at some point during childhood orpuberty, all people lose the mental capacity required in order to achieve anative standard in an additional language.
5) Results and Conclusion
Carroll, J. B., & Sapon, S., 1959. Modern Language Aptitude Test: FormA. New York: The Psychological Corporation.Bley-Vroman, R., 1988. The fundamental character of foreignlanguage learning. In W. Rutherford & M. Sharwood Smith (Eds.),Grammar and second language teaching: A book of readings (pp. 19– 30). Rowley,MA: Newbury House.Johnson, J. and Newport, E., 1989. Critical period effects in secondlanguage learning: The influence of maturational state on theacquisition of English as a second language. Cognitive Psychology, 21(1),pp.60-99.Lenneberg, E., 1967. Biological foundations of language. New York: Wiley.Ottó, I. (1996). Hungarian language aptitude test: Words in sentences.Unpublished manuscript, Department of English Applied Linguistics,Eötvös Loránd University, Budapest.Penfield, W. and Roberts, L., 1959. Speech and Brain Mechanisms.Princeton, New Jersey: Princeton University Press.Transparent. 2021. Take Hungarian Language Quizzes. [online] Availableat: <https://www.transparent.com/learn-hungarian/quizzes/lotw-quizzes/> [Accessed 8 April 2021].
The main purpose of DeKeyser’s study researching the Fundamental Difference hypothesis and the robustness of the Critical Period is to replicate the results of a study conducted by Johnson and Newport (1989). Their investigation proved the Fundamental Difference hypothesis correct, affirming the fact that the Critical Period does exist. In addition to this, DeKeyser recognised that not a single empirical study has been conducted which tests the Fundamental Difference hypothesis to test its various features (DeKeyser, 2000, p.500). The findings obtained from his study would therefore be instrumental to the second language acquisition research field. Through taking methodological criticisms into account highlighted in the subsequent years after Johnson and Newport’s study (1989),
De Keyser formed the following three hypotheses to investigate (DeKeyser, 2000, p.507-508).
1) Participants in this study will show a strong negative correlationbetween age of arrival and performance on a grammaticalityjudgement test, but with some overlap in range between child andadult acquirers2) Those adult acquirers who score within the range of childacquirers will all have high verbal aptitude, which may haveallowed them, at least in part, to learn the L2 grammar through explicitreflection on rules3) Different elements of grammar will show differentcorrelations with age of acquisition; not all structures are equallysensitive to the critical period effect
2) Rationale and Research Hypotheses
The participants in DeKeyser’s study were 57 native speakers of Hungarian (32 male and 25 female) from a 200-mile radius surrounding Pittsburgh, Pennsylvania. In order to obtain results from an unbiased and varied sample, the participants came from a wide range of ages and varying socioeconomic status levels. As an additional requirement for the study, the participants had to be living in the United States for at least ten years without having been significantly exposed to English until their migration to an English-speaking country.
DeKeyser employed three research instruments in order to test his hypotheses. Each participant was met with either individually in their own home or in a room on the University of Pittsburgh campus (DeKeyser, 2000, p.510). The first part of the study was a Background Questionnaire. It was two pages long and consisted of general questions about individual variables such as their language and educational background, their age of arrival in North America and age at time of test (DeKeyser, 2000, p.510).The second part of the study was the Grammaticality JudgementTest. Through using the framework from Johnson and Newport’s study(1989), the individual listened to 200 items which had been tape-recorded by a male native speaker of English. Each item had beenpaired with another, and the participant was required to identify odd andirregular pairs (DeKeyser, 2000, p.509-510). The test took around 55minutes to complete.The final part of the investigative procedure was the LanguageLearning Aptitude Test, modelled by that of Carroll and Sapon(1959) and amended into Hungarian by Ottó (1996). Overapproximately a 20-minute period, participants were required to readstimulus sentences from a sheet and elect the correct answers from amultiple-choice selection. The test consisted of 20 five-way multiplechoice items.
Student ID: XXXXX
Grammaticality Judgement Test Example
A snake bit she on the leg.*Susan is making some cookies for us.The baby bird was has fall from the oak tree. *The little boy was counting all his pennies last night.(DeKeyser, 2000, p.527)
Language Learning Aptitude Test ExampleInkább egy kétágyas [room] szeretnék fürdőszobávala) Szobát b) kettő c) szálloda
Megvan a [my ticket] a 492-es járatra?a) Elvámolnivalóim b) helyfoglalásom c) jegyem(Transparent, 2021)