Continuity theory is a concept used in various disciplines including psychology, sociology, and anthropology that suggests that individuals maintain their personalities and behavior patterns throughout their lives. There are several synonyms that are used to refer to continuity theory, such as life-course theory and developmental trajectory theory. Another synonym is the "stability change theory," which posits that changes occur in development throughout the lifespan, but some parts of individuals' personality or behavior patterns remain stable. Additionally, the term "persistence theory" explores how individuals continue to exhibit certain behaviors in the face of changing circumstances. All these terms aim to describe the same basic idea, which is that individuals maintain a level of continuity in their behavior across different contexts.