History of Personality and Intelligence Theory and Research

Abstract

Personality theory has been aimed primarily at developing an inclusive description of persons, while intelligence theory has been aimed at a more specific question: What is a person's cognitive potential to adapt to environmental demands? Both subdisciplines developed within the context of individual-differences research, especially in their early history. Individual-differences research has been contrasted with studies in what often has been labeled experimental or hardcore psychology, characterized by controlled experiments with independent and dependent variables. Individual-differences research used primarily correlational procedures and descriptive statistics. It is obvious from a review of the history of psychology that the ``two psychologies'' differentiation (Cronbach, 1957) did not accurately characterize all of psychological research, although there was a fairly pervasive methodological split at one time. As personality theory evolves, it would be expected to increasingly integrate data from all branches of psychology and other disciplines into an inclusive scientific model of persons. This is the challenge that this chapter addresses.