Autistic children at risk of being underestimated: school-based pilot study of a strength-informed assessment

An important minority of school-aged autistic children, often characterized as 'nonverbal' or 'minimally verbal,' displays little or no spoken language. These children are at risk of being judged 'low-functioning' or 'untestable' via conventional cognitive testing practices. One neglected avenue for assessing autistic children so situated is to engage current knowledge of autistic cognitive strengths. Our aim was thus to pilot a strength-informed assessment of autistic children whose poor performance on conventional instruments suggests their cognitive potential is very limited.

Thirty autistic children (6 to 12 years) with little or no spoken language, attending specialized schools for autistic children with the highest levels of impairment, were assessed using Wechsler Intelligence Scale for Children (WISC-IV), Raven's Colored Progressive Matrices board form (RCPM), Children's Embedded Figures Test (CEFT), and a visual search task. An age-matched control group of 27 typical children was also assessed.

None of the autistic children could complete WISC-IV; only six completed any subtest. In contrast, 26 autistic children could complete RCPM, with 17 scoring between the 5th and 90th percentile. Twenty-seven autistic children completed the visual search task, while 26 completed CEFT, on which autistic children were faster than RCPM-matched typical children. Autistic performance on RCPM, CEFT, and visual search were correlated.

These results indicate that 'minimally verbal' or 'nonverbal' school-aged autistic children may be at risk of being underestimated: they may be wrongly regarded as having little cognitive potential. Our findings support the usefulness of strength-informed approaches to autism and have important implications for the assessment and education of autistic children.