The relationship between severity of motor stereotypy and nonverbal IQ in autistic preschoolers

Abstract

This study investigates the relationship between severity of motor stereotypy and nonverbal IQ in autistic preschoolers. It was hypothesized that there is an inverse relationship between nonverbal IQ and severity of motor stereotypy (i.e. the lower the IQ, the more severe the stereotypies). Although it has been observed clinically that motor stereotypies differ in autistic spectrum disordered children with various IQ levels, there has not been previous empirical study of the relationship.;Subjects were 41 children, aged 3 through 7 years, selected from an overall parent study on language disorders. The children were videotaped in 50-minute play sessions for the parent project, prior to this research. IQ tests and the Autistic Disorders Checklist were also administered at the subject's entrance into the parent project. The subjects were rated on the Motor Stereotypy Checklist developed for this study. This checklist was designed in order to measure the frequency of motor stereotypies and the extent to which the stereotypies interfere with functioning. It consists of four sections: Movement Stereotypies, Body-Oriented Stereotypies, Stereotypic Behavior in Relation to Object/Toy (both Sensory and Ritualistic Manipulation of Object/Toy) and Fixity. Inter-rater reliability was obtained for this instrument.;Results conclude that a statistically significant inverse relationship was found between nonverbal IQ and severity of motor stereotypy. These results indicate that higher functioning autistic children, as determined by their IQ, exhibit fewer motor stereotypies. Similarly, lower functioning children, as determined by their IQ, display more severe and frequent stereotypies.;The findings are discussed in terms of providing school psychologists and research-clinicians for a rapid way in which to cognitively assess and efficiently plan effective educational interventions for preschool aged autistic youngsters.