The Relationship between Spoken Language Ability and Intelligence Test Performance of Deaf Children and Adolescents

Abstract

For several decades the intellectual abilities of deaf children and adolescents, as measured by performance IQ, have been reported as comparable with those of hearing children and adolescents. Differences have been reported, however, on measures of verbal IQ, with deaf children and adolescents typically obtaining verbal IQ scores within the low average to well below average range. More recent studies of the intellectual abilities of deaf children and adolescents using the Wechsler scales, while supporting this finding, have not taken into consideration all subgroups within the deaf and adolescent population nor accounted for the degree of variability in their language abilities. The aim of this study was to investigate intelligence test performance for subgroups of deaf children and adolescents who communicate using spoken English and for whom language ability is known. To do this, two groups of participants were included in the study: those with age appropriate spoken language (AA) and those with a spoken language delay (LD). Results showed that the AA group scored significantly higher on all measures of performance and verbal IQ than the LD group. The performance and verbal IQs of the LD group were similar to those of previous studies of deaf children and adolescents. The results of this study extend and elaborate on current views of intelligence and deafness and the potential impact that spoken language ability has on intelligence test performance for different subgroups within the deaf child and adolescent population, particularly those who communicate using spoken language. Copyright © 2007 John Wiley & Sons, Ltd.