After reviewing classic and current conceptions of trait(as measured by questionnaires) and motive(as measured by the Thematic Apperception Test [TAT] or other imaginative verbal behavior), the authors suggest that these 2 concepts reflect 2 fundamentally different elements of personality—conceptually distinct and empirically unrelated. The authors propose that traits and motives interact in the prediction of behavior: Traits channel the behavioral expression of motives throughout the life course. The authors illustrate this interactive hypothesis in 2 longitudinal studies, focusing on the broad trait of extraversion and the 2 social motives of affiliation and power. In interaction with extraversion, both motives show predicted and replicated relations to independently measured life outcomes in the domains of relationships and careers. Extraversion facilitates unconflicted motive expression, whereas introversion deflects social motives away from their characteristic goals and creates difficulties in goal attainment.