Aptitude complexes and trait complexes

The origins and development of the concept of aptitude complexes are reviewed. Initial empirical success in demonstrating interactions between aptitude complexes and instructional complexes by Richard E. Snow and his students is followed by an inductive approach to finding broader trait complexes. Three empirical studies of college students and adults up to age 62 are described, where trait complexes were correlated with domain knowledge and ability measures. Differentiated profiles of trait complex-knowledge-ability correlations were found and replicated across the 3 studies. Evidence for trait complexes that are supportive or impeding for the development of domain knowledge is reviewed. The aptitude complex-trait complex approach is viewed as an important means toward researching and reevaluating the nature of aptitude-treatment interactions.