A Factor Analysis Study of Intellectual Development in Deaf and Hearing Children

Explanations of cognitive functioning in the deaf have been marred by the use of inappropriate measurement instruments, comparisons based' on the average performance of deaf and hearing subjer.s, and failure to consider developmental changes across age levels. In the present study the Snijders-Oomen Nonverbal Intelligence Test (SON) was adminis.ered to 251 deaf children and 101 hearing children in Israel. The SON is appropriate for measuring cognitive functioning in the deaf because it requires.no verbal instruct:Ions or responses by the subject and it includes a measure of abstract thinking ability. Factor analysis was done separately for older and younger subjects to determine the developmental nature of the underlying structure of intelligence in the deaf and hearing. The four main findings were: (1) the factor structure for the total deaf group differs from the hearing group, (2) differences in cognitive structure are evident by age level for the deaf, (3) differences exist between the cognitive structures of hearing and deaf subjec,:s of the same age, and (4) a similar abstract thinking component is found for hearing and older deaf subjects. Thus, empirical support was provided for a shift from previous theories that the deaf are limited to concrete thinking to a position that the deaf use different coping mechanisms in performing cognitive tasks and that ae abstract thinking component of their intellectual structure 4pears later than that of their hearing peers. The findings of this study are discussed in terms of both their theoretical and methodological implications for reaching a better understanding of the cognitive development of deaf children.