A psychological and social concept that explains how romantic relationships and marriage choices develop from inception to final commitment. Introduced by social psychologist Bernard Murstein in the 1960s, the concept focuses on the process of getting to know a partner through three successive stages: stimulus, values, and role, emphasizing that relationships gradually develop from initial attraction to full compatibility in mutual goals, values, and roles in the marital relationship. An analytical concept that describes the process of choosing a romantic and marital partner through three successive stages: the stimulus stage, where the initial attraction is based on external characteristics; the stage of values, where compatibility in values and beliefs is assessed; and the role stage, where the ability of both partners to fulfill the expected roles in the marital relationship is tested in order to find a partner who is as compatible as possible both emotionally and socially.