Snyder's (1974) construct of self-monitoring in communication refers to the degree of self-observation and self-control, guided by situational cues to social appropriateness. To investigate the relationship of level of self-monitoring (high or low) to the ability to accurately discriminate varying levels of incongruent communication, 62 college students (31 males, 31 females) completed the Incongruency Discrimination Assessment (IDA), rating 12 videotaped scenes. The 12 scenes systematically reflected three levels of incongruence (highly congruent, mildly incongruent, highly incongruent), and two types of incongruence (context and affect). Subjects were classified as high or low self-monitors on the basis of their scores on Snyder's Personal Reaction Inventory. An analysis of the results showed that subjects rated levels of incongruence higher as the degree of incongruent behavior increased. A main effect for type of incongruence was also revealed, with the content mode consistently receiving higher incongruence ratings than the affective mode. There was no significant difference between high and low self-monitors on perceptions of incongruence. The findings fail to support the self-monitoring hypothesis. (BL)