Background: There is a substantial base of literature studying the relationship between general intelligence and autism spectrum disorder (ASD). However, the study of this relationship has produced varied results, possibly due to the evolution of diagnostic criteria, measurement, and latent constructs within psychology. We aimed to assess the degree to which core ASD symptom severity relates to aspects of general intellectual functioning, and determine whether this relationship is sensitive to different versions of IQ tests. Method: We conducted a factor analysis on Wechsler Intelligence Scale for Children, fifth edition (WISC-V) (N=83) and Wechsler Intelligence Scale for Children, fourth edition (WISC-IV) (N=131) data in children with ASD and examined the relationship between factors and Autism Diagnostic Observational Schedule (ADOS) performance. Then, we compared the data-driven factor analysis with the manualized IQ indices. We also examined the WISC-IV in a typically developing (TD) cohort (N=209). Results: Results showed that the data-driven factor analysis in TDs was tightly correlated with the manual-derived indices, ADOS scores in children with ASD were poorly correlated with full-scale IQ and manualized indices in WISC-V but were more strongly correlated with IQ test results in the WISC-IV group, and there was weaker correlation between data-driven factors and manualized IQ index scores in the ASD group than in the TD group. Conclusions: While the most recent version of the WISC is less influenced by symptoms of ASD, index-level scores are impacted to the point that the structure of the hierarchy itself differs between groups, possibly due to working memory.
Autism Symptom Severity and the Structure of Intelligence
