A proposed model of intelligence and its implications for children with Autism Spectrum Disorder

Thesis (Ph. D.)--University of Rochester. Department of Clinical and Social Sciences in Psychology, 2016.Although research indicates that IQ tests are reliable and valid measures of cognition when administered to individuals with autism spectrum disorder (ASD), it also reveals that such tests have unusual psychometric properties in this population, notably low intercorrelation among subtests, distinctive patterns of strengths and weaknesses, and overprediction of everyday functioning. A comprehensive explanation for these differences has yet to be offered. This study evaluates a new model of the structure of intelligence in the ASD population that, if confirmed, would help account for the differences. A threedomain model is proposed, consisting of language ability, perceptual ability, and social ability, with each ability further broken down into a fluid reasoning component and crystalized knowledge component. Fifty-three children with ASD, ages 6-12, with full scale IQ scores above 50, were assessed on a standardized IQ test (Stanford-Binet Intelligence Test, 5th Edition), a test of social skills (NEPSY-II), and parent-rated adaptive behavior (Vineland Adaptive Behavior Scales II), social skills (Social Skills Improvement System – Rating Scales), and executive functioning (BRIEF). Factor scores were estimated from 6 items (Verbal Knowledge, Verbal Fluid Reasoning, Nonverbal Knowledge, and Nonverbal Fluid Reasoning from the SB-5; Affect Recognition and Theory of Mind from the NEPSY-II), and a path analysis was conducted to test the fit of a model relating these factors to (1) constructs representing cognitive abilities and adaptive abilities, (2) constructs representing the components of the new model proposed in this study (language abilities, perceptual abilities, and social abilities), and (3) constructs representing the impact of executive functioning on the new model. On the whole, results supported the use of the SB-5 with school-age children with ASD. The proposed model was partially supported with the inclusions of social skills and only 4 subtests of the SB-5 predicting adaptive behavior as well as the full IQ test. The inclusion of executive functioning in the model as an additional construct of cognition was not supported