Sullivan's theory suggests that the self-system, acquire through early childhood interactions, serves as a filter for interpersonal interactions, maintaining personal security and self-esteem. It evolves through identity formation and security operations like selective attention, denial, repression, rationalization, and dissociation. These mechanisms can be adaptive or maladaptive, depending on their impact on personal growth and relationships. the dynamic interaction between the self-system and security operations is crucial for emotional resilience.