Journal of Autism and Developmental Disorders

, Volume 19, Issue 4, pp 483–499

The role of age at assessment, developmental level, and test in the stability of intelligence scores in young autistic children

  • Catherine Lord
  • Eric Schopler

DOI: 10.1007/BF02212853

Cite this article as:
Lord, C. & Schopler, E. J Autism Dev Disord (1989) 19: 483. doi:10.1007/BF02212853


Longitudinal comparisons were made of intelligence and developmental quotient (IQ/DQ) scores for three age groups of 70–72 autistic children aged 2 to 3, 4 to 5, and 6 to 7 years at initial assessment and reassessed at least 2 years later. Stability and predictability over a mean follow-up period of 5 years were related to age, developmental level, and test used at initial assessment. IQ/DQs during preschool years were quite stable and predictive of later IQ scores, except when early scores on the Bayley Scales of Mental Development were compared with later scores on performance or nonverbal tests. As for other populations, predictability for young autistic children was strongest when the same test was used at both assessments, and when children were 4 years or older at initial assessment.

Copyright information

© Plenum Publishing Corporation 1989

Authors and Affiliations

  • Catherine Lord
    • 1
  • Eric Schopler
    • 2
  1. 1.Department of PediatricsUniversity of Alberta and Glenrose Rehabilitation HospitalEdmontonCanada
  2. 2.Division TEACCH, Department of PsychiatryUniversity of North CarolinaUSA
  3. 3.Greensboro TEACCH ClinicGreensboro

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