The purpose of this research is to identify the interrelation among the three capabilities of self-talk, self-complexity, and interpersonal communication. We predicted that self-reflection and analysis through self-talk will affect cognitive development. Self-complexity, the skill that makes one`s perception of his or her role more complex, is estimated to help understanding one`s own role as well as relationships with others through interpersonal communication. This paper aims to look at the interrelation among the three capabilities and confirm the routes of the relationship among the three. A survey was created and conducted on 151 university students. These questionnaires were used to grant uniformity to the survey methods because they are self-reflecting questions. Considering the role of oneself and others within interpersonal relationships, self-talk standards and self-complexity questionnaires that recognize one`s own role have been used. Results showed an interrelation among the three capabilities and confirmed that self-talk directly affects interpersonal communication and also has an indirect effect through self-complexity. Thus, this paper confirmed the routes among the three capabilities of self-talk, self-complexity, and interpersonal communication.