A total of 78 mental health clients participating in therapy groups completed self-report measures corresponding to narcissistic personality defects derived from a self-psychology perspective and ratings of themselves on a checklist of interpersonal behavior. Also, pairs of group leaders were asked to rate clients on interpersonal behaviors. Results indicated a clear convergence of narcissistic needs and self-perceptions of interpersonal behaviors: Those with strong grandioseexhibitionistic needs viewed themselves as having both dominant and friendly behavior, whereas those with strong idealizing needs viewed themselves as being submissive and moderately hostile. Therapist ratings of interpersonal behaviors did not yield as many significant correlations with self-ratings of narcissistic needs: Those with grandiose-exhibitionistic needs were observed using dominant behavior and those with idealizing needs were observed using submissive behavior.The premise of this study is that the narcissistic needs of the self should be related to interpersonal behavior. Kohut (1971Kohut ( , 1977Kohut ( , 1984 constructed a comprehensive developmental theory called psychology of the self, in which narcissistic needs refer to the natural striving toward self-expression or self-promotion that is central to all personality development. From this perspective, self-expression and narcissism are parts of the same developmental process, in which the self increasingly relies on internal rather than external sources both to maintain a sense of permanence and well-being and to develop native talents and skills. Pathological narcissism is a result of faulty self-development and results in the maladaptive use of interpersonal relations to promote self-expression. Kohut (1971) theorized that the self is the initiating center of the personality and reflects basic narcissistic or self-expressive needs contained in two lines of development, the grandiose-exhibitionistic and the idealizing (a third line, the alter ego, was tentatively incorporated into the theory (Kohut, 1984) just prior to Kohut's death and is not used in this article). In the young child, the needs of the self are met through important others, who provide external sources of support and encouragement. Through phase-appropriate and nontraumatic lapses in parental empathy, the child begins to internally regulate a sense of stability and security and to use his or her native talents and skills. More specifically, in the grandiose-exhibitionistic sector, the immature self uses the admiration and approval of others to provide a sense of selfworth, whereas in the mature self, self-esteem and ambition are internally regulated. In the idealizing sector, the immature This project was funded in part by a biomedical grant-in-aid from Virginia Commonwealth University.We thank Donald J. Kiesler for assistance with the design and interpretation of this study and Stephen Herrick for help with the calculations of the intraclass correlation coefficients.