Using self-discrepancy theory as a theoretical framework, this study examines the interactive effects of self-monitoring and type of self-guide (i.e., own vs. other standpoint) on the relationship between self-discrepancies and affective states. Over two sessions, 294 undergraduates completed the Self-Monitoring Scale, the Selves Questionnaire (either from the own or other standpoint), the Beck Depression Inventory, the Hopkins Symptom Checklist, and the Social Anxiety subscale of the Self-Consciousness Scale. For low self-monitors, depression and anxiety were predicted only by self-discrepancies from the own standpoint on the self. For high self-monitors, depression and anxiety were more strongly predicted by self-discrepancies from the other than the own standpoint on the self. The authors discuss the role of individual differences in understanding when self-discrepancies have implications for individuals' affective states.According to early self-theorists (e.g., Cooley, 1902Cooley, / 1964 James, 1890James, /1896Mead, 1934), individuals experience continuity of the self and at the same time possess many self-beliefs. At any point in time, however, only a limited number of self-beliefs can be actively processed. Those self-relevant beliefs that are accessible at any point in time have been defined as constituting the working self-concept (Markus & Kunda, 1986). Markus and Wurf (1987) argued that the information constituting the working self-concept can be influenced both by internal introspective processes and by the external context within which the self is situated. For example, the working self-concept can be based on a reflection of one's personal goals, needs, or values and/or be influenced by expectations and perceptions of important others.There are likely to be chronic individual differences in the extent to which people rely on internal versus external sources of information in constructing the working self-concept. We pursue the question of whether individual differences in personality regulate the strength of the relationship between the valence of one's self-related beliefs and emotional states such as anxiety and depression. For individuals who chronically construct their self-concepts on the basis of internal information, situationally salient internal self-relevant information should exert a greater influence on their emotional states than situationally salient external self-relevant information. In contrast, for people who chronically construct their self-concepts on the basis of external information, situationally salient external self-relevant information should exert a greater influence on their emotional states than would situationally