Language Abilities are Associated with Both Verbal and Nonverbal Intelligence in Children on the Autism Spectrum

ABSTRACT

Intellectual abilities factor into levels of functioning used to characterize autism. Language difficulties are highly prevalent in autism and may impact performance on measures of intellectual abilities. As such, nonverbal tests are often prioritized in classifying intelligence in those with language difficulties and autism. However, the relationship between language abilities and intellectual performance is not well characterized, and the superiority of tests with nonverbal instructions is not well established. The current study evaluates verbal and nonverbal intellectual abilities in the context of language abilities in autism and the potential benefit of tests with nonverbal instructions. Participants were 55 children and adolescents on the autism spectrum who underwent a neuropsychological evaluation as part of a study examining language functioning in autism. Correlation analyses were performed to examine relations between expressive and receptive language abilities. Language abilities (CELF−4) were significantly correlated with all measures of both verbal (WISC-IV VCI) and nonverbal intelligence scores (WISC-IV PRI and Leiter-R). There were no significant differences between nonverbal intelligence measures with verbal or nonverbal instructions. We further discuss the role of assessment of language abilities in interpreting results of intelligence testing in populations with higher prevalence of language difficulties

KEYWORDS:

• language abilities
• verbal intelligence
• nonverbal intelligence
• IQ
• autism

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by grants from NIH awarded to JDL (R01 HD051747; R41 DC013197) and CD (K23 DC016637; R01 DC019167) and from Autism Speaks awarded to CD (11637).