This research proposes a novel method to quantify the similarities among adjectives by utilizing the concept of Big Five model. This research verifies the proposed method through three types of group: social group, interpersonal group, and couple. The results reveal that ”openness to experience” is the indicator for the natural formation of an interpersonal group. Conscientiousness is the indicator for the formation of a task-oriented group. Couples mostly have at least one construct of similarity. In summary, result shows the cohesion of a group has various effects on particular constructs of Big Five model based on demands and environment.