This editorial suggests how the approaches of differential psychology and information processing psychology should be combined to study intelligence. Methods reviewed include factor analysis, componential analysis, and computer simulation. Guidelines for the specification of subtheories of intelligence, as well as future theories and methods for…

Analysis of the mental factors of seventh grade students indicates that numerical facility and perceptual speed are a single factor at this age level and that no purely verbal factor exists. Seven clearly differentiated factors are found for males and five for females. (Author/WY)