Abilities Structure of Congenitally Blind Persons: A Factor Analysis

Abstract

A principal component factor analysis with varimax rotation was performed for a sample of male adult congenitally blind persons. Seventeen variables were measured, including the six WAIS Verbal subtests, the six HISAB subtests, the Category Width Scale, the Repression-Sensitization Scale, the Rigidity Scale, a measure of sophistication of body concept, and vision. The analysis produced five factors, three of which are small specific factors. The first common factor, described as nonverbal ability, is of substantial magnitude and suggests that these measures clearly assess areas of intellectual functioning not tapped by verbal testing alone, and that level of useful vision is a highly important consideration in evaluating the test performance of this group. The second common factor is described as verbal intelligence, and it is proposed that much of the variance involved in tests of Information, Vocabulary, Similarities, and Comprehension can be attributed to verbal memory and that these four tests provide an adequate assessment of learning potential for this group. Standard regression coefficients for computing factor scores are provided. The validity data presented should facilitate the application of the cognitive style approach to further research with congenitally blind persons.