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Maturational Constraints on Language Development

Published online by Cambridge University Press:  07 November 2008

Michael H. Long
Michael H. Long
Affiliation:
University of Hawaii, Manoa
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Abstract

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This article reviews the second language research on age-related differences, as well as first language work needed to disambiguate some of the findings. Five conclusions are drawn, (a) Both the initial rate of acquisition and the ultimate level of attainment depend in part on the age at which learning begins. (b) There are sensitive periods governing language development, first or second, during which the acquisition of different linguistic abilities is successful and after which it is irregular and incomplete. (c) The age-related loss in ability is cumulative (not a catastrophic one-time event), affecting first one linguistic domain and then another, and is not limited to phonology, (d) The deterioration in some individuals begins as early as age 6—not at puberty as is often claimed. (e) Affective, input, and current cognitive explanations for the reduced ability are inadequate. The capacity for language development is maturationally constrained, and its decline probably reflects a progressive loss of neural plasticity, itself possibly associated with increasing myelination.

Type
State of the art
Information
Studies in Second Language Acquisition , Volume 12 , Issue 3 , September 1990 , pp. 251 - 285
Copyright
Copyright © Cambridge University Press 1990

References

REFERENCES

Adiv, E. (1980). An analysis of second language performance in two types of immersion programs. Unpublished PhD thesis, McGill University, Montreal.Google Scholar
Asher, J., & Garcia, R. (1969). The optimal age to learn a foreign language. Modern Language Journal, 53, 334–341.CrossRefGoogle Scholar
Asher, J., & Price, B. (1967). The learning strategy of total physical response: Some age differences. Child Development, 38, 1219–1227.CrossRefGoogle ScholarPubMed
Ausubel, D. P. (1968). Educational psychology: A cognitive view. New York: Holt, Rinehart and Winston.Google Scholar
Bateson, P. P. G. (1973). Internal influences on early learning in birds. In Hinde, R. A. & Stephenson-Hinde, (Eds.), Constraints on learning (pp. 77–102). New York: Academic.Google Scholar
Bellugi, U. (1967). The acquisition of negation. Unpublished PhD thesis, Harvard University, Cambridge, MA.Google Scholar
Bland, M., & Keislar, E. (1966). A self-controlled audio-lingual program for children. French Review, 40, 266–276.Google Scholar
Bley-Vroman, R. (in press). The logical problem of foreign language learning. Linguistic Analysis.Google Scholar
Brainerd, C. J. (1978). Learning research and Piagetian theory. In Siegel, L. S. & Brainerd, C. J. (Eds.), Alternatives to Piaget: Critical essays on the theory (pp. 69–109). New York: Academic.Google Scholar
Brown, H. D. (1979, February). A socioculturally determined critical period for second language acquisition. Paper presented at the 13th Annual TESOL Convention, Boston, MA.CrossRefGoogle Scholar
Burstall, C., Jamieson, M., Cohen, S., & Hargreaves, M. (1974). Primary French in the balance. Windsor, UK: National Foundation for Educational Research.Google Scholar
Clahsen, H., & Muysken, P. (1986). The availability of universal grammar to adult and child learners—A study of the acquisition of German word order. Second Language Research, 2, 93–119.Google Scholar
Cochrane, R. (1980). The acquisition of /r/ and /l/ by Japanese children and adults learning English as a second language. Journal of Multilingual and Multicultural Development, 1, 331–360.CrossRefGoogle Scholar
Collier, V. (1987). Age and rate of acquisition of second language for academic purposes. TESOL Quarterly, 21, 617–641.CrossRefGoogle Scholar
Colombo, J. (1982). The critical period concept: Research, methodology, and theoretical issues. Psychological Bulletin, 91, 260–275.CrossRefGoogle ScholarPubMed
Cook, V. (1988). Chomsky's universal grammar. Oxford: Blackwell.Google Scholar
Coppieters, R. (1987). Competence differences between native and fluent non-native speakers. Language, 63, 544–573.CrossRefGoogle Scholar
Cummins, J. (1981). Age on arrival and immigrant second language learning in Canada. Applied Linguistics, 11, 132–149.CrossRefGoogle Scholar
Curtiss, S. R. (1977). Genie: A linguistic study of a modern day “wild child.” New York: Academic.Google Scholar
Curtiss, S. R. (1980). The critical period and feral children. UCLA Working Papers in Cognitive Linguistics, 2, 21–36.Google Scholar
Curtiss, S. R. (1982). Developmental dissociation of language and cognition. In Obler, L. K. & Menn, L. (Eds.), Exceptional languages and linguistics (pp. 285–312). New York: Academic.Google Scholar
Curtiss, S. R. (1988). Abnormal language acquisition and the modularity of language. In Newmeyer, F. J. (Ed.), Linguistics: The Cambridge Survey: Vol. 2. Linguistic theory: Extensions and implications (pp. 96–116). Cambridge: Cambridge University Press.Google Scholar
D'Anglejan, A., & Renaud, C. (1985). Learner characteristics and second language acquisition: A multivariate study of adult immigrants and some thoughts on methodology. Language Learning, 35, 1–19.CrossRefGoogle Scholar
David, S. (1985). The acquisition of the phonological features of a second dialect. Unpublished master's thesis, University of South Carolina, Columbia.Google Scholar
Diller, K. (1981). ‘Natural methods’ of foreign language teaching: Can they exist? What criteria must they meet? In Winnitz, H. (Ed.), Native language and foreign language acquisition. Annals of the New York Academy of Sciences, 379, 75–91.Google ScholarPubMed
Ekstrand, L. (1976). Age and length of residence as variables related to the adjustment of migrant children, with special reference to second language learning. In Nickel, G. (Ed.), Proceedings of the Fourth International Congress of Applied Linguistics (Vol. 3, pp. 179–198). Stuttgart: Hochschulverlag.Google Scholar
Ekstrand, L. (1978). English without a book revisited: The effect of age on second language acquisition in a formal setting. Didakometry, 60. Malmo, Sweden: Department of Educational and Psychological Research, School of Education, Malmo University.Google Scholar
Ellis, R. (1985). Understanding second language acquisition. Oxford: Oxford University Press.Google Scholar
Ervin-Tripp, S. M. (1974). Is second language learning like the first? TESOL Quarterly, 8, 111–127.CrossRefGoogle Scholar
Fathman, A. K. (1975). The relationship between age and second language learning ability. Language Learning, 25, 245–253.CrossRefGoogle Scholar
Fathman, A. K., & Precup, L. (1983). Influences of age and setting on second language oral proficiency. In Bailey, K. M., Long, M. H., & Peck, S. (Eds.), Second language acquisition studies (pp. 151–161). Rowley, MA: Newbury House.Google Scholar
Feldman, H., Goldin-Meadow, S., & Gleitman, L. R. (1978). Beyond Herodotus: The creation of language by linguistically deprived deaf children. In Locke, A. (Ed.), Action, gesture and symbol: The emergence of language (pp. 102–123). London: Academic.Google Scholar
Felix, S. W. (1981). On the (in)applicability of Piagetian thought to language learning. Studies in Second Language Acquisition, 3, 201–220.CrossRefGoogle Scholar
Felix, S. W. (1985). More evidence on competing cognitive systems. Second Language Research, 1, 47–72.Google Scholar
Fillmore, C. J., Kempler, D., & Wang, W. S-Y. (1979). Individual differences in language ability and language behavior. New York: Academic.Google Scholar
Flege, J. E. (1987). A critical period for learning to pronounce foreign languages? Applied Linguistics, 8, 162–177.CrossRefGoogle Scholar
Florander, J., & Jansen, M. (1969). Skoleforsog i engelsk 1959–1965. Unpublished manuscript, Denmark Institute of Education, Copenhagen.Google Scholar
Genesee, F. (1976). The role of intelligence in second language learning. Language Learning, 26, 267–280.CrossRefGoogle Scholar
Genesee, F. (1983). Bilingual education of majority language children: The immersion experiments in review. Applied Psycholinguistics, 4, 1–46.CrossRefGoogle Scholar
Genesee, F. (1988). Neuropsychology and second language acquisition. In Beebe, L. M. (Ed.), Issues in second language acquisition: Multiple perspectives (pp. 81–112). Cambridge, MA: Newbury House.Google Scholar
Gleitman, L. R. (1986). Biological programming for language learning. In Friedman, S. L., Klivington, K. A., & Peterson, R. W. (Eds.), The brain, cognition, and education (pp. 119–149). New York: Academic.CrossRefGoogle Scholar
Goldin-Meadow, S. (1982). The resilience of recursion: A study of a communication system developed without a conventional language model. In Wanner, E. & Gleitman, L. R. (Eds.), Language acquisition: State of the art (pp. 51–77). Cambridge: Cambridge University Press.Google Scholar
Gould, J., & Marler, P. (1987, 01). Learning by instinct. Scientific American, 256, 74–85.CrossRefGoogle Scholar
Gregg, K. R. (1984). Krashen's monitor and Occam's razor. Applied Linguistics, 5, 79–100.CrossRefGoogle Scholar
Grinder, R., Otomo, A., & Toyota, W. (1962). Comparisons between second, third and fourth grade children in the audio-lingual learning of Japanese as a second language. The Journal of Educational Research, 56, 463–469.CrossRefGoogle Scholar
Guiora, A., Ben-Hallahmi, B., Brannon, R., Dull, C, & Scovel, T. (1972). The effects of experimentally induced changes in ego states on pronunciation ability in a second language: An exploratory study. Comprehensive Psychiatry, 73, 421–428.CrossRefGoogle Scholar
Guiora, A., & Schonberger, R. (1989, May). Native pronunciation of bilinguals. Paper presented at the first annual JAAL conference, Aoyama Gakuin University, Tokyo.Google Scholar
Harley, B. (1982). Age-related differences in the acquisition of the French verb system by anglophone students in French immersion programs. Unpublished PhD thesis, University of Toronto.Google Scholar
Harley, B. (1986). Age in second language acquisition. Clevedon, UK: Multilingual matters.Google Scholar
Hatch, E. M. (1977). Optimal age or optimal learners? Workpapers in TESL, 11, 45–56.Google Scholar
Hatch, E. M. (1983). Psycholinguistics: A second language perspective. Rowley, MA: Newbury House.Google Scholar
Hinde, R. A. (1970). Animal behavior (2nd ed.). New York: McGraw-Hill.Google Scholar
Hyltenstam, K. (1977). Implicational patterns in interlanguage syntax variation. Language Learning, 27, 383–411.CrossRefGoogle Scholar
Immelmann, K., & Suomi, S. (1981). Sensitive phases in development. In Immelmann, K., Barlow, G., Petrinovich, L., & Main, L. (Eds.), Behavioral development: The Bielefeld Interdisciplinary Project. Cambridge: Cambridge University Press.Google Scholar
Ioup, G. (1984). Is there a structural foreign accent? A comparison of syntactic and phonological errors in second language acquisition. Language Learning, 34, 1–17.CrossRefGoogle Scholar
Jacobs, B. (1988). Neurobiological differentiation of primary and secondary language acquisition. Studies in Second Language Acquisition, 10, 303–337.CrossRefGoogle Scholar
James, S. L, & Kahn, L. M. L. (1982). Grammatical morpheme acquisition: An approximate invariant order? Journal of Psycholinguistic Research, 11, 381–388.CrossRefGoogle Scholar
Johnson, J. S., & Newport, E. L. (1989). Critical period effects in second language learning: The influence of maturational state on the acquisition of English as a second language. Cognitive Psychology, 21, 60–99.CrossRefGoogle ScholarPubMed
Jones, M., & Quigley, S. (1979). The acquisition of question formation in spoken Spanish and American Sign Language by two hearing children of deaf parents. Journal of Speech and Hearing Disorders, 44, 196–208.CrossRefGoogle Scholar
Kennedy, B. L. (1988). Adult versus child L2 acquisition: An information-processing approach. Language Learning, 38, 477–495.CrossRefGoogle Scholar
Krashen, S. D. (1973). Lateralization, language learning and the critical period: Some new evidence. Language Learning, 23, 63–74.CrossRefGoogle Scholar
Krashen, S. D. (1982). Accounting for child-adult differences in second language rate and attainment. In Krashen, S. D., Scarcella, R. C., & Long, M. H. (Eds.), Child-adult differences in second language acquisition (pp. 202–226). Rowley, MA: Newbury House.Google Scholar
Krashen, S. D., Long, M. H., & Scarcella, R. C. (1979). Age, rate, and eventual attainment in second language acquisition. TESOL Quarterly, 13, 573–582.CrossRefGoogle Scholar
Krashen, S. D., Scarcella, R. C., & Long, M. H. (Eds.). (1982). Child-adult differences in second language acquisition. Rowley, MA: Newbury House.Google Scholar
Lamendella, J. (1977). General principles of neurofunctional organization and their manifestation in primary and non-primary acquisition. Language Learning, 27, 155–196.CrossRefGoogle Scholar
Lecours, A. R. (1975). Myelogenetic correlates of the development of speech and language. In Lenneberg, E. H. & Lenneberg, E. (Eds.), Foundations of language development (Vol. 1). New York: Academic.Google Scholar
Lenneberg, E. H. (1967). Biological foundations of language. New York: Wiley.CrossRefGoogle Scholar
Lowenthal, K., & Bull, D. (1984). Imitation of foreign sounds: What is the effect of age? Language and Speech, 27, 95–97.CrossRefGoogle Scholar
Major, R. (1987). Foreign accent: Recent research and theory. International Review of Applied Linguistics, 15, 185–202.Google Scholar
Mason, M. (1942). Learning to speak after six and one half years of silence. Journal of Speech Disorders, 7, 295–304.CrossRefGoogle Scholar
Matsunobu, J. T. (1981). A sore thumb? Identifying the ESL writer. Unpublished paper, University of Pennsylvania, Philadelphia.Google Scholar
Maxwell, D. L. (1984). The neurology of learning and language disabilities: Developmental considerations. In Wallach, G. P. & Butler, K. G. (Eds.), Language learning disabilities in school-age children (pp. 35–59). London: Williams and Wilkins.Google Scholar
Mayberry, R., Fischer, S., & Hatfield, N. (1983). Sentence repetition in American Sign Language. In Kyle, J. & Woll, B. (Eds.), Language in sign: International perspectives on sign language (pp. 83–97). London: Croom Helm.Google Scholar
McKinney, V. (1983). First language learning in deaf persons beyond the critical period. Unpublished PhD thesis, Clairemont Graduate School, Clairemont, CA.Google Scholar
McLaughlin, B. (1984). Second-language acquisition in childhood: Volume 1. Preschool children (2nd ed.). Hillsdale, NJ: Erlbaum.Google Scholar
Mehler, J., Morton, J., & Jusczyk, P. (1984). On reducing language to biology. Cognitive Neuropsychology, 1, 83–116.CrossRefGoogle Scholar
Mimura, K. (1986). Development of visual pattern discrimination in the fly depends on light experience. Science, 232, 83–85.CrossRefGoogle ScholarPubMed
Morris, B. S. K., & Gerstman, L. J. (1986). Age contrasts in the learning of language-relevant materials: Some challenges to critical period hypotheses. Language Learning, 36, 311–352.CrossRefGoogle Scholar
Neufeld, G. (1977). Language learning ability in adults: A study on the acquisition of prosodic and articulatory features. Working Papers on Bilingualism, 12, 45–60.Google Scholar
Neufeld, G. (1978). On the acquisition of prosodic and articulatory features in adult language learning. Canadian Modern Language Review, 34, 163–174.CrossRefGoogle Scholar
Neufeld, G. (1979). Towards a theory of language learning ability. Language Learning, 29, 227–241.CrossRefGoogle Scholar
Newport, E. (1984). Constraints on learning: Studies in the acquisition of American Sign Language. Paper and Reports on Child Language Development, 23, 1–22.Google Scholar
Newport, E., & Supalla, T. (forthcoming). Critical period effects in the acquisition of a primary language.Google Scholar
Olson, L., & Samuels, S. J. (1973). The relationship between age and accuracy of foreign language pronunciation. Journal of Psycholinguistic Research, 66, 263–267.Google Scholar
Oyama, S. C. (1976). A sensitive period for the acquisition of a phonological system. Journal of Psycholinguistic Research, 5, 261–283.CrossRefGoogle Scholar
Oyama, S. C. (1978). The sensitive period and comprehension of speech. Working Papers on Bilingualism, 16, 1–17.Google Scholar
Oyama, S. C. (1979). The concept of the sensitive period in developmental studies. Merrill-Palmer Quarterly, 25, 83–103.Google Scholar
Patkowski, M. (1980a). The sensitive period for the acquisition of syntax in a secondary language. Unpublished PhD thesis, New York University, New York.Google Scholar
Patkowski, M. (1980b). The sensitive period for the acquisition of syntax in a second language. Language Learning, 30, 449–472.CrossRefGoogle Scholar
Patkowski, M. (1982). The sensitive period for the acquisition of syntax in a second language. In Krashen, S. D., Scarcella, R. C., & Long, M. H. (Eds.), Child-adult differences in second language acquisition (pp. 52–63). Rowley, MA: Newbury House.Google Scholar
Patkowski, M. (1990). Age and accent in a second language: A reply to James Emil Flege. Applied Linguistics, 11, 73–89.CrossRefGoogle Scholar
Pavesi, M. (1986). Markedness, discoursal modes, and relative clause formation in a formal and an informal context. Studies in Second Language Acquisition, 8, 38–55.CrossRefGoogle Scholar
Payne, A. (1980). Factors controlling the acquisition of the Philadelphia dialect by out-of-state children. In Labov, W. (Ed.), Locating language in time and space (pp. 143–178). New York: Academic.Google Scholar
Penfield, W., & Roberts, L. (1959). Speech and brain mechanisms. New York: Atheneum.Google Scholar
Purcell, E. T., & Suter, R. W. (1980). Predictors of pronunciation accuracy: A reexamination. Language Learning, 30, 271–287.CrossRefGoogle Scholar
Ramirez, A. G., & Politzer, R. L. (1978). Comprehension and production in English as a second language by elementary school children and adolescents. In Hatch, E. M. (Ed.), Second language acquisition: A book of readings (pp. 313–332). Rowley, MA: Newbury House.Google Scholar
Ramsey, C. A., & Wright, E. N. (1974). Age and second language learning. The Journal of Social Psychology, 94, 115–121.CrossRefGoogle Scholar
Ritchie, W. C. (1978). The right roof constraint in an adult-acquired language. In Ritchie, W. C. (Ed.), Second language acquisition research (pp. 33–63). New York: Academic.Google Scholar
Rosansky, E. (1975). The critical period for the acquisition of language: Some cognitive developmental considerations. Working Papers on Bilingualism, 6, 10–23.Google Scholar
Sachs, J., Bard, B., & Johnson, M. L. (1981). Language learning with restricted input: Case studies of two hearing children of deaf parents. Applied Psycholinguistics, 2, 33–54.CrossRefGoogle Scholar
Scarcella, R. C. (1983). Discourse accent in second language performance. In Gass, S. & Selinker, L. (Eds.), Language transfer in language learning (pp. 306–322). Rowley, MA: Newbury House.Google Scholar
Scarcella, R. C., & Higa, C. A. (1982). Input and age differences in second language acquisition. In Krashen, S. D., Scarcella, R. C., & Long, M. H. (Eds.), Child-adult differences in second language acquisition (pp. 175–201). Rowley, MA: Newbury House.Google Scholar
Schiff, N. (1979). The influence of deviant maternal input on the development of language during the preschool years. Journal of Speech and Hearing Research, 22, 581–603.CrossRefGoogle ScholarPubMed
Schmid, E. (1986). A comparative study of children's and adults' acquisition of tone accents in English. Language Learning, 36, 185–210.CrossRefGoogle Scholar
Schmidt, R. W. (1981). Interaction, acculturation and the acquisition of communicative competence. University of Hawaii Working Papers in Linguistics, 13, 29–77.Google Scholar
Schumann, J. H. (1975). Affective factors and the problem of age in second language acquisition. Language Learning, 25, 209–235.CrossRefGoogle Scholar
Scovel, T. (1969). Foreign accents, language acquisition, and cerebral dominance. Language Learning, 19, 245–254.CrossRefGoogle Scholar
Scovel, T. (1981). The recognition of foreign accents in English and its implications of psycholinguistic theories of language acquisition. In Savard, J-G. & Laforge, L. (Eds.), Proceedings of the 5th Congress of AILA (pp. 389–401). Laval, Canada: University of Laval Press.Google Scholar
Scovel, T. (1988). A time to speak. A psycholinguistic inquiry into the critical period for human speech. Cambridge, MA: Newbury House.Google Scholar
Seliger, H. W. (1978). Implications of a multiple critical periods hypothesis for second language learning. In Ritchie, W. (Ed.), Second language acquisition research (pp. 11–19). New York: Academic.Google Scholar
Seliger, H. W., Krashen, S. D., & Ladefoged, P. (1975). Maturational constraints in the acquisition of second language accent. Language Sciences, 36, 20–22.Google Scholar
Seright, L. (1985). Age and aural comprehension achievement in francophone adults learning English. TESOL Quarterly, 79(3), 455–473.CrossRefGoogle Scholar
Singleton, D. (1989). Language acquisition. The age factor. Clevedon, UK: Multilingual matters.Google Scholar
Slobin, D. I. (1982). Universal and particular in the acquisition of language. In Wanner, E. & Gleitman, L. R. (Eds.), Language acquisition: State of the art (pp. 128–170). Cambridge: Cambridge University Press.Google Scholar
Snow, C. E. (1983). Age differences in second language acquisition: Research findings and folk psychology. In Bailey, K. M., Long, M. H., & Peck, S. (Eds.), Second language acquisition studies (pp. 141–150). Rowley, MA: Newbury House.Google Scholar
Snow, C. E. (1987). Relevance of the notion of a critical period to language acquisition. In Bernstein, M. (Ed.), Sensitive periods in development: An interdisciplinary perspective (pp. 183–209). Hillsdale, NJ: Erlbaum.Google Scholar
Snow, C. E., & Hoefnagel-Hohle, M. (1977). Age differences and the pronunciation of foreign sounds. Language and Speech, 20, 357–365.CrossRefGoogle ScholarPubMed
Snow, C. E., & Hoefnagel-Hohle, M. (1978). The critical period for language acquisition: Evidence from second language learning. Child Development, 49, 1114–1128.CrossRefGoogle Scholar
Strong, M. (1984). Integrative motivation: Cause or result of successful second language acquisition? Language Learning, 34, 1–14.CrossRefGoogle Scholar
Studdert-Kennedy, M. (1985). The beginnings of speech. In Immelman, K., Barlow, G., Petrinovich, L., & Main, L. (Eds.), Behavioral development: The Bielefeld Interdisciplinary Project (pp. 533–561). Cambridge: Cambridge University Press.Google Scholar
Swain, M. (1985). Communicative competence: Some roles of comprehensible input and comprehensible output in its development. In Gass, S. M. & Madden, C. G. (Eds.), Input in second language acquisition (pp. 235–253). Rowley, MA: Newbury House.Google Scholar
Tahta, S., Wood, M., & Lowenthal, K. (1981a). Age changes in the ability to replicate foreign pronunciation and intonation. Language and Speech, 24, 363–372.CrossRefGoogle Scholar
Tahta, S., Wood, M., & Lowenthal, K. (1981b). Foreign accents: Factors relating to transfer of accent from the first language to a second language. Language and Speech, 24, 265–272.CrossRefGoogle Scholar
Taylor, B. (1974). Toward a theory of language acquisition. Language Learning, 24, 23–36.CrossRefGoogle Scholar
Thogmartin, C. (1982). Age, individual differences in musical and verbal aptitude, and pronunciation achievement by elementary school children learning a foreign language. International Review of Applied Linguistics, 20, 66–72.Google Scholar
Toutaiolepo, V. J. (1984). Stalking the wild ESL writer. Unpublished paper, University of Hawaii, Honolulu.Google Scholar
Walberg, H., Hase, K., & Pinzur Rasher, S. (1978). English acquisition as a diminishing function of experience rather than age. TESOL Quarterly, 12, 427–437.CrossRefGoogle Scholar
Wald, B. (1986). Syntactic development after childhood: Beyond the vernacular? In Sankoff, D. (Ed.), Diversity and diachrony. Current issues in linguistic theory (Vol. 53, pp. 153–170). Amsterdam: John Benjamins.Google Scholar
Weber-Olsen, M., & Ruder, K. (1980). Acquisition and generalization of Japanese locatives by English speakers. Applied Psycholinguistics, 3, 127–198.Google Scholar
Whitaker, H., Bub, D., & Leventer, S. (1981). Neurolinguistic aspects of language acquisition and bilingualism. Annals of the New York Academy of Sciences, 379, 59–74.CrossRefGoogle ScholarPubMed
White, L. (1985). The “pro-drop” parameter in adult second language acquisition. Language Learning, 35, 47–62.CrossRefGoogle Scholar
Woodward, J. C. (1973). Some characteristics of pidgin sign English. Sign Language Studies, 3, 39–59.CrossRefGoogle Scholar
Yamada, J., Takatsuka, S., Kotabe, N., & Kuruse, J. (1980). On the optimum age for teaching foreign vocabulary to children. International Review of Applied Linguistics, 28, 245–247.Google Scholar
Young, R. (1981). Sign language acquisition in a deaf adult: A test of the critical period hypothesis. Unpublished PhD thesis, University of Georgia, Athens.Google Scholar