Woodcock -Johnson Tests of Cognitive Abilities -Third Edition and Universal Nonverbal Intelligence Test IQ scores: Does autism diagnosis make a difference?

The primary purpose of this study was to investigate intellectual assessment of individuals with an Autism Spectrum Disorder (ASD). Specifically, the study attempted to determine if there were significant differences among two intellectual assessments, the Woodcock-Johnson Tests of Cognitive Abilities- Third Edition (WJ IV COG) and the Universal Nonverbal Intelligence Test (UNIT), between three ASD including highfunctioning autism (HFA), Asperger Syndrome (AS), and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS). Sixty-five participants were recruited through notices placed in local newspapers to find children ages 8 to 18 years of age with an ASD diagnosis from a physician, licensed psychologist, or pediatric neurologist. Results showed that there were no significant differences between HFA and AS on any of the intellectual measures including WJ III COG GIA, UNIT Full Scale, as well as other scores from these tests. However, children with AS had significantly higher scores than POD-NOS children on the UNIT Reasoning Quotient and the WJ III COG Verbal Comprehension subtest. Implications of the results of this study were discussed.