Autistic features in school age children: IQ and gender effects in a population-based cohort

Level and characteristics of intellectual function (IQ) have been associated with symptom presentation in children with autism spectrum disorder. The present study examined associations between IQ and autistic features in a sample of school aged boys and girls selected from a population-based cohort. The study included detailed examinations of 325 children aged 8-12 years, selected from the sample of the Bergen Child Study. IQ was assessed using the third version of the Wechsler Intelligence Scale for Children (WISC-III) and autistic features by parent reports on the Autism Spectrum Screening Questionnaire (ASSQ). Boys obtained higher ASSQ scores than girls. Gender and FSIQ had main effects on ASSQ scores, with the ASSQ scores showing a gradual decline with higher FSIQ for both genders. Discrepancies between verbal and performance IQ were relatively unrelated to ASSQ scores. The findings emphasize the importance of conducting careful assessments of children before reaching conclusions about cognitive function and autistic features.