Specific weaknesses of high-functioning autistic children on the Leiter-3 International Performance Scale

The assessments of non-verbal intelligence in individuals with Autism Spectrum Disorder (ASD) may be subject to biases. This study compared the scores obtained on the most recent version of the Leiter scale by 18 children with high-functioning ASD and 18 typically-developing controls, who were matched for age, sex, and IQ estimated using the Raven’s Coloured Matrices. ASD children performed worse than controls on all virtually subtests and areas of the Leiter-3, including non-verbal IQ, attention-related, and working memory ability. It is suggested that the high degree of social interaction required by the Leiter-3 makes its use problematic for ASD children.