Final answer:
Self-development involves the process of developing a sense of self from infancy to adulthood, influenced by various psychological factors.
Step-by-step explanation:
Self-development, or the development of one's sense of self, occurs through various stages and processes. According to psychologists like Sigmund Freud and Erik Erikson, self-development begins in infancy and continues throughout adolescence and adulthood. In infancy, babies develop self-awareness and a sense of identity. In adolescence, individuals explore different identities and strive to form a solid sense of self. Finally, in adulthood, having a positive self-concept is essential for healthy development and the ability to form intimate relationships.