Our article presents work on the development and validation of Influence Regulation and Deinfluentization Scale (DEI-beh). Reviewing concepts regarding its influence constitutes an introduction to the original deinfluentization concept coined by Barbara Kożusznik. The author’s theory has provided the basis for creating a diagnostic tool. The elaborated DEI-beh method consists in evaluating conditions which determine managerial effectiveness and shape reciprocal influences among team members. Our article describes this tool’s creation and its validation procedure. Positive relationships between DEI-beh’s individual dimensions and temperament characteristics, defined in Pavlov’s concept (1952), and selected personality traits, proposed in the Five-Factor Model Personality by Costa and McCrae (1992), confirm the tool’s external validity
