Skip to main content Accessibility help

The relation of utterance length to grammatical complexity in normal and language-disordered groups

  • Hollis S. Scarborough (a1), Leslie Rescorla (a2), Helen Tager-Flusberg (a3), Anne E. Fowler (a4) and Vicki Sudhalter (a5)...


Mean length of utterance (MLU) in morphemes was examined as a predictor of the grammatical complexity of natural language corpora of normal preschoolers and of children and adolescents with delayed language, Fragile X syndrome, Down syndrome, and autism. The Index of Productive Syntax (IPSyn) served as the measure of syntactic and morphological proficiency. For all groups, a strong curvilinear association between measures was found across the MLU range from 1.0 to about 4.5. Correlations were weaker when MLU exceeded 3.0 than during earlier stages of language development, however, confirming previous suggestions that MLU becomes less closely associated with grammatical development as linguistic proficiency increases. For the language-disordered groups, moreover, the curves relating the two measures differed from the curves for the normal preschoolers because MLU frequently overestimated actual IPSyn scores. The results are discussed with respect to the use of MLU in conjunction with other measures of syntactic complexity in the study of atypical language development.


Corresponding author

H. Scarborough, Department of Psychology, Brooklyn College, CUNY, Brooklyn, NY 11210


Hide All
Baron-Cohen, S. (1989). Do autistic children have obsessions and compulsions? British Journal of Clinical Psychology, 28, 193200.
Bayley, N. (1969). Bayley Scales of Infant Development. New York: Psychological Corp.
Bloom, L. (1970). Language development: Form and function in emerging grammars. Cambridge, MA: MIT Press.
Bloom, L. (1973). One word at a time. The Hague: Mouton.
Bloom, L., Lightbown, P., & Hood, L. (1975). Structure and variation in child language. Monographs of the Society for Research in Child Development, 40(2).
Brown, R. (1973). A first language: The early stages. Cambridge, MA: Harvard University Press.
Cohen, D. J., Paul, R., & Volkmar, F. (1986). Issues in the classification of pervasive and other developmental disorders: Toward DSM-IV. Journal of the American Academy of Child Psychiatry, 25, 213220.
Cohen, D. J., Paul, R., & Volkmar, F. (1987). Issues in the classification of pervasive developmental disorders and associated conditions. In Cohen, D. J. & Donnellan, A. M. (Eds.), Handbook of autism and pervasive developmental disorders (pp. 2040). New York: Wiley.
Crystal, D. (1974). A review of Brown’s A first language. Journal of Child Language, 1, 289307.
Crystal, D., Fletcher, P., & Garman, M. (1976). The grammatical analysis of language disability: A procedure for assessment and remediation. New York: Elsevier.
Denckla, M. B. (1986). New diagnostic criteria for autism and related behavioral disorders: Guidelines for research protocols. Journal of the American Academy of Child Psychiatry, 25, 221224.
de Villiers, J. G., & de Villiers, P. A. (1973). A cross-sectional study of the acquisition of grammatical morphemes in child speech. Journal of Psycholinguistic Research, 2, 267278.
Fowler, A. E. (1985). Language acquisition in Down syndrome children: Production and comprehension (Doctoral dissertation, University of Pennsylvania, 1984). Dissertation Abstracts International, 46(1–B), 324.
Fowler, A. E. (1988). Determinants of rate of language growth in children with Down syndrome. In Nadel, L. (Ed.), The psychobiology of Down syndrome. Cambridge, MA: MIT/Bradford.
Fowler, A. E. (1990). Language abilities in children with Down syndrome: Evidence for a specific syntactic delay. In Cicchetti, D. & Beeghly, M. (Eds.), Down syndrome: The developmental perspective (pp. 302328). New York: Cambridge University Press.
Fowler, A., Gelman, R., & Gleitman, L. (1980, October). A comparison of normal and retardate language equated on MLU. Paper presented to the Boston University Conference on Child Language Development, Boston.
Hollingshead, A. B., & Redlich, F. C. (1958). Social class and mental illness. New York: Wiley.
Johnston, J., & Schery, T. (1976). The use of grammatical morphemes by children with communication disorders. In Morehead, D. & Morehead, A. (Eds.), Normal and deficient child language (pp. 239258). Baltimore: University Park Press.
Johnston, J. R., & Kamhi, A. (1984). The same can be less: Syntactic and semantic aspects of the utterances of language impaired children. Merrill-Palmer Quarterly, 30, 6586.
Klee, T., & Fitzgerald, M. D. (1985). The relation between grammatical development and mean length of utterance in morphemes. Journal of Child Language, 12, 251269.
Klima, E., & Bellugi, U. (1966). Syntactic regularities in the speech of children. In Lyons, J. & Wales, R. (Eds.), Psycholinguistic papers. Edinburgh: Edinburgh University Press.
Kramer, C. A., James, S. L., & Saxman, J. H. (1979). A comparison of language samples elicited at home and in the clinic. Journal of Speech and Hearing Disorders, 44, 321330.
MacWhinney, B., & Walter, J. (1987). CHAT manual. Transcript Analysis, 4, 152.
Miller, J. F., & Chapman, R. S. (1985). Systematic analysis of language transcripts: User’s guide. Madison: University of Wisconsin Language Analysis Laboratory.
Morehead, D., & Ingram, D. (1973). The development of base syntax in normal and linguistically deviant children. Journal of Speech and Hearing Research, 16, 330352.
Nelson, K. (1973). Structure and strategy in learning to talk. Monographs of the Society for Research in Child Development, 38 (Serial No. 149).
Newport, E. L., Gleitman, H., & Gleitman, L. (1977). Mother I’d rather do it myself: Some effects and non-effects of maternal speech style. In Snow, C. E. & Ferguson, C. A. (Eds.), Talking to children: Language input and acquisition. Cambridge: Cambridge University Press.
Rescorla, L. (1989). The language development survey: A screening tool for the identification of language delay in toddlers. Journal of Speech and Hearing Disorders, 54, 587599.
Rescorla, L., & Schwartz, E. (1990). Outcome of specific expressive language delay. Applied Psycholinguistics, 11, 393407.
Reynell, J. K. (1985). Reynell developmental language scales. Windsor, UK: NFER-Nelson.
Rondal, J. A. (1978). Developmental sentence scoring procedure and the delay-difference question in language development of Down’s syndrome children. Mental Retardation, 16, 169171.
Rondal, J. A., Ghiotto, M., Bredart, S., & Bachelet, J. (1987). Age-relation, reliability and grammatical validity of measures of utterance length. Journal of Child Language, 14, 433446.
Rutter, M. (1978). Diagnosis and definition. In Rutter, M. & Schopler, E. (Eds.), Autism: A reappraisal of concepts and treatment (pp. 125). New York: Plenum.
Scarborough, H. S. (1989). Prediction of reading disability from familial and individual differences. Journal of Educational Psychology, 81, 101108.
Scarborough, H. S. (1990). Index of Productive Syntax. Applied Psycholinguistics, 11, 122.
Scarborough, H. S., & Dobrich, W. (1985). Illusory recovery from early language delay. Proceedings of the Symposium on Research on Child Language Disorders, 6, 9099.
Scarborough, H. S., & Dobrich, W. (1990). Development of children with early language delay. Journal of Speech and Hearing Research, 33, 7083.
Shipley, E. F., Smith, C., & Gleitman, L. R. (1969). A study in the acquisition of language: Free responses to commands. Language, 45, 322342.
Sparrow, S. S., Balla, D. A., & Cicchetti, D. V. (1984). Vineland Adaptive Behavior Scales. Circle Pines, MN: American Guidance Co.
Sudhalter, V., Cohen, I. L., Silverman, W., & Wolf-Schein, E. G. (1990). Conversational analyses of males with Fragile X, Down syndrome, and autism: A comparison of the emergence of deviant language. American Journal on Mental Retardation, 94, 431441.
Tager-Flusberg, H., Calkins, S., Nolin, T., Baumberger, T., Anderson, M., & Chadwick-Dias, A. (1990). A longitudinal study of language acquisition in autistic and Down syndrome children. Journal of A utism and Developmental Disorders, 20, 121.
Terman, L. M., & Merrill, M. A. (1973). Stanford-Binet Intelligence Scale: 1972 norms edition. Boston: Houghton Mifflin.
Wells, G. (1985). Language development in the preschool years. Cambridge: Cambridge University Press.
Wiegel-Crump, C. A. (1981). The development of grammar in Down’s syndrome children between the MA’s of 2–0 and 6–11 years. Education and Training of the Mentally Retarded, 6, 2460.
Wolf-Schein, E. G., Sudhalter, V., Cohen, I. L., Fisch, G. S., Hanson, D., Pfadt, A. G., Hagerman, R., Jenkins, E. C., & Brown, W. T. (1987, 07). Speech-language and the Fragile X syndrome: Initial findings. American Speech-Language Hearing Association, 3538.


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed