Cognition, Education, and Deafness: Directions for Research and Instruction

A Factor-Analytic Study of Intellectual Development in Deaf and Hearing Children

A Factor-Analytic Study of Intellectual Development in Deaf and Hearing Children Abraham Zwiebel Donna M. Mertens Two major schools of thought have attempted to explain cognitive functioning in the deaf: Myklebust's (1964) organismic shift hypothesis and Furth's (1971) view that no difference exists between deaf and hearing subjects in conceptual performance, at least up to concrete-operational thinking. The results of factor-analytic studies of the differential ability structure for deaf and hearing children (Bolton, 1978; Farrant, 1964; Holmberg, 1966; Juurmaa, 1963) have generally agreed with Myklebust's organismic shift hypothesis. Myklebust hypothesized that the deaf were quantitatively equal, but qualitatively inferior, to the hearing in that the deaf develop a more concrete, and, therefore, less abstract intelligence. Myklebust and Brutton (1953) stated that deafness "restricts the child functionally to a world of concrete objects and things" (p. 93). Bolton (1978) found little support in the factor-analytic studies for Furth's (1971) position that the deaf reach a plateau in their thinking. Furth (1964) labeled the deaf as "linguistically deficient" because they do not use "the living language as heard and spoken in our society" (p. 47). This linguistic deficiency supposedly restricts the cognitive development of deaf individuals to concrete-operational thinking. Furth emphasized that the use of verbal tests to assess deaf children's intelligence was not fair. The position in the present study was that neither the factor-analytic work that supports the Myklebust hypothesis nor Furth's conclusion concerning the plateau reached by the deaf are accurate representations of the nature of intelligence in a deaf population. The major problem with the factor-analytic work is that it has aggregated data across age groups and thus obscured differences in developmental progression. Even the most recent study by Bolton (1978) did not find any rationale for different factors in deaf and hearing populations using limited IQ stimuli such as performance scales. Many studies report that deaf children lag behind hearing children at early ages, but that the lags are often not observed in older children (Canabal, 1970; Hoemann & Briga, 1980). Available evidence suggests that the condition of deafness imposes no limitation on the cognitive capabilities of individuals (Moores, 1982; Ottem, 1980; Rittenhouse & Spiro, 1970). No evidence suggests that a deaf person thinks in more concrete ways than a hearing person. Previous findings of a plateau in the development of deaf intelligence seem to have been the result of using tests and instructions that were inappropriate to the deaf population . A fair test of the intelligence of deaf children must (a) ensure the ability of the experimenter to communicate the instructions to the deaf, (b) avoid the heavily verbal nature of many intelligence tests, and (c) cover the We offer a special note of thanks to Steve Wolk, Chair, Department of Educational Foundations and Research, Gallaudet College, for his guidance and support during the data analysis and reporting. 151 Measurement of Cognitive Potential in Hearing-Impaired Learners entire intellectual span, including evaluation of abstract thinking. The Snijders-Oomen Nonverbal Intelligence Test (SON) fits all of these criteria (Harris, 1982; Kearney, 1969; Kyle, 1980). The present study used factor-analytic techniques to examine the nature of cognitive development in deaf children. The factor analyses were done separately for younger and older groups in order to determine developmental differences; the SON was used as a measure of intelligence. This test is appropriate for assessing the intelligence of deaf children in that the items are restricted to the performance type that can be visually demonstrated and imitated. In addition, the subscales cover all the subareas of intelligence. Methodology Subjects The subjects included 251 deaf children ages 6 to 15 (approximately 25 children from each age level) who were randomly selected (stratified by age and sex) from the population of all Israeli deaf children in special education settings in 1975 and 1976. The deaf children were divided evenly by sex, 125 boys and 126 girls, with the same proportion (50%) at each age level. This sample represents 62% of the total population. Twelve percent of the sample were deaf children of deaf parents, most also had deaf siblings.Thirty percent of the deaf children of hearing parents also had at least one deaf sibling. The demographic data indicate a slightly greater representation from the lower socioeconomic level of the Israeli population. More than 85% of the subjects were profoundly deaf from birth. All the children attended oraloriented educational settings (the only system in Israel). Sixty percent of the deaf subjects were...