IQ discrepancy differentiates levels of fine motor skills and their relationship in children with autism spectrum disorders.

Purpose: We investigated 1) the impact of differences in intelligence quotient discrepancy (IQD) on motor skills of preschool-aged children with autism spectrum disorders (ASD); 2) the relationships between IQD and motor skills in preschool-aged children with ASD.
Methods: A total of 127 ASD preschool-aged children were divided into three groups according to the size of the IQD: IQD within 1 standard deviation (1SD; EVENIQ; n=81), discrepantly higher verbal intelligence quotient (VIQ; n=22; VIQ>performance intelligence quotient [PIQ] above 1SD [≥15 points]), and discrepantly higher PIQ (n=24; PIQ>VIQ above 1SD [≥15 points]). Children's IQD and motor skills were determined with the Wechsler Preschool and Primary Scale of Intelligence™ - Fourth Edition and the motor subtests of the Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT), respectively.
Results: One-way analysis of variance revealed significant group differences for the fine motor domain of the CDIIT and the visual-motor coordination subtest ( F =3.37-4.38, p <0.05). Children with discrepantly higher PIQ were associated with better fine motor skills than were children with even IQD and those with discrepantly higher VIQ, and vice versa. IQD (PIQ - VIQ) had significant positive correlations with the fine motor domain and fine motor subtests of the CDIIT ( r =0.18-0.29, p <0.05).
Conclusion: The IQD can identify different levels of fine motor skills in preschool-aged children with ASD. This study suggests important implications for clinicians, therapists, and researchers: discrepantly higher PIQ could be related to better visual-motor coordination, and discrepantly higher VIQ could be related to poor visual-motor coordination. Furthermore, the results support that when therapists are working with preschool-aged children with ASD who are developing fine motor skills or undertaking fine motor tasks related to visual-motor coordination, they may need to pay attention to the children's IQD.
Competing Interests: Disclosure The authors report no conflicts of interest in this work.