A Study on the Peak-to-Valley Characteristics of Intellectual Structure in Low-Functioning Children With Autism Spectrum Disorder.

Autism Spectrum Disorder (ASD) is marked by a distinctive cognitive profile reflecting neurodiversity, yet whether this profile extends consistently across the functional spectrum remains uncertain. In this study, we examined the intellectual structure of children with low-functioning ASD (LF-ASD) and high-functioning ASD (HF-ASD), comparing their cognitive peak-valley profiles using the Chinese Wechsler Intelligence Scale for Children (C-WISC). Among 314 children aged 6-13 years-including 104 with LF-ASD, 122 with HF-ASD, and control groups with typical development (TD) or intellectual disabilities (ID)-both ASD subgroups displayed significantly greater discrepancies between verbal and performance IQ than controls, with pronounced strengths in visuospatial tasks and weaknesses in arithmetic reasoning. Notably, the Block Design and Object Assembly subtests emerged as cognitive peaks across both ASD groups, whereas the Arithmetic subtest constituted the most frequent trough. Although the mean peak-valley discrepancy was slightly reduced in LF-ASD compared to HF-ASD, both exceeded the 2 standard deviation (SD) threshold for neurodiversity, distinguishing them from the TD and ID groups. These profiles were positively associated with adaptive functioning and inversely related to ASD symptom severity. Our findings suggest that children with LF-ASD exhibit intellectual asymmetries comparable to those of HF-ASD, supporting the universality of neurodiversity within the autism spectrum and offering valuable insights for tailoring cognitive interventions.