Trait psychology, psycho-dynamics, situationism, and interactionism, the four basic models of personality, are summarized; controversies they have generated and relevant research are discussed. Special emphasis is placed on interactional psychology as a model of personality theory and research. Controversial issues of personality such as consistency versus specificity, persons versus situations, mediating versus reaction variables, and mechanistic versus dynamic interaction are presented. The role of situations in personality research and theory is identified. The interaction model of anxiety, a special case of the interaction model of personality, is described and empirical support for this model is discussed. Potential applications of the interaction model of anxiety are presented. Specifically this model is discussed with respect to possible applications for psychotherapy, academic achievement, surgery, and athletics. The limitations of interactionism are presented and directions for future research are described. (Author/PN)