Factor Structure of the Wechsler Intelligence Scale for Children at Pre-School Level and after First Grade: A Longitudinal Analysis

Abstract

In order to determine the changes in mental factor structure with increasing age and educational maturity, two factor analytic studies were made. In 1961, 163 pre-school children were examined with the Wechsler Intelligence Scale for Children and 4 reference tests. One year later this test battery was repeated with 153 of the same children. The 10 standard WISC subtests, except coding, were split into 2, 3, or 4 parts to yield as many variables as possible. Kaiser's varimax rotation was applied to the 30 by 30 matrix. Evidence is presented supporting 8 statistically significant uncorrelated factors at the pre-school level and 10 factors after 1 yr. of school. At least 6 factors are readily identified by WISC subtests, or by combinations of WISC subtests. Our findings support Garrett's developmental theory of intelligence. By age 6 differential mental abilities are clearly discernible. Six factors extracted at pre-school level are stable and congruent with those found after 1 yr. of school.