The Relation Between Adaptive Behavior and Intelligence: Testing Alternative Explanations

Adaptive behavior has become an increasingly important component of the assessment of children referred for learning and behavioral problems in educational settings. Yet the construct of adaptive behavior remains ill defined, and fundamental questions about the nature of adaptive behavior remain unanswered. As a result, measures of adaptive behavior are often problematic. Among the most important of these fundamental questions is the nature of the underlying relation between adaptive behavior and intelligence. The present study used confirmatory factor analysis and 556 schoolage children from the overlap of the standardization sample of the Vineland Adaptive Behavior Scale and the Kaufman Assessment Battery for Children to test three models of the relation between adaptive behavior and intelligence: as identical underlying construrts, as completely unrelated constructs, or as separate but related constructs. The model specifying adaptive behavior and intelligence as separate but related constructs proved significantly better than either competing model. Similar results were obtained for preschool children and low-ability school-age children, further suggesting that adaptive behavior and intelligence should be considered as separate but related constructs. Two plausible models to further explain the natwe of this relation are presented.