Cognitive and verbal abilities of 24- to 36-month-old siblings of children with autism

J Autism Dev Disord. 2007 Feb;37(2):218-29. doi: 10.1007/s10803-006-0163-5.


The cognitive and language skills of 30 siblings of children with autism (SIBS-A) and 30 siblings of typically developing children (SIBS-TD) were compared. Non-significant group differences emerged for cognition at both ages. At 24 months, significantly more SIBS-A demonstrated language scores one or two standard deviations below the mean compared to SIBS-TD. At 36 months, the groups differed significantly in receptive language, and more SIBS-A displayed receptive and expressive difficulties compared to SIBS-TD. Six SIBS-A (including one diagnosed with autism) revealed language scores more than two standard deviations below the mean at both ages, a pattern not seen in the SIBS-TD. Results are discussed in reference to language difficulties in autism spectrum disorders and the genetic liability for autism.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Autistic Disorder / epidemiology*
  • Child Development
  • Child, Preschool
  • Cognition Disorders / diagnosis
  • Cognition Disorders / epidemiology*
  • Female
  • Humans
  • Infant
  • Language Development Disorders / diagnosis
  • Language Development Disorders / epidemiology
  • Male
  • Severity of Illness Index
  • Siblings*
  • Surveys and Questionnaires
  • Verbal Behavior*