Conjoint Effects of Intelligence and Adaptive Behavior on Achievement in a Nonreferred Sample

Abstract

This study examined the conjoint effects of intelligence and adaptive behavior on subsequent achievement in a nonreferred sample. Scores from the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R) and the Vineland Adaptive Behavior Scale-Classroom Edition (VABS-CE) were collected for 51 kindergarten children. These kindergarten scores subsequently were compared with the children's second-grade achievement in reading, spelling, language, and math. Results indicated a moderate overall relationship between intelligence and adaptive behavior scores (r = .31, p < .05), which corroborates earlier evidence that these are separate, but related constructs. As in previous studies, achievement was predicted best by intelligence (r = .67, p < .001). However, in the areas of reading, language, and math achievement, adaptive behavior contributed significant additional predictive power (117% for total achievement), even after intelligence had been taken into account.