Because cognitive categories associated with the evaluation of a working relationship are stable at times, yet dynamic under specific conditions, understanding leader-member exchange (LMX) and identifying cognitive correlates associated with exchange quality is perplexing (Foti, Knee & Backert, 2008). The purpose of this study was to investigate how congruence between a leader's and follower's leader and follower prototypes affects the quality of the leader-member exchange relationship as assessed by each partner in the dyadic pair. Leaders and followers in 68 dyadic pairs performed a series of tasks in a laboratory setting. Multiple assessments of liking and trust for each other, as well as LMX quality from their perspective were made. Congruence on leader prototypes significantly predicted follower assessed LMX; followers' liking and trust for leaders fully mediated this relationship. In addition, congruence on follower prototypes significantly predicted leader assessed LMX; leaders' liking for followers fully mediated this relationship. These results emphasize the reciprocal nature of LMX relationships. Practical implications of having high quality LMX include, but are not limited to, higher satisfaction and commitment, less conflict, and higher performance ratings. / Master of Science