Final answer:
The idea that conflicts in early life need to be resolved for healthy development is related to the psychoanalytic theory, specifically Freud's psychosexual development theory and Erikson's psychosocial development theory.
Step-by-step explanation:
The idea that early conflicts must be resolved in order for healthy psychosocial development to take place is related to the psychoanalytic theory. Sigmund Freud's theory of psychosexual development and Erik Erikson's psychosocial development theory both emphasize that childhood experiences and stages are crucial to resolving conflicts that can affect an individual's personality and behavior as an adult. Freud examined how each stage centers around a certain erogenous zone and believed that if a person doesn't receive proper nurturance during a specific development phase, they may become fixated, leading to a range of adult personality and behavior issues. Meanwhile, Erikson expanded upon Freud's ideas and presented his psychosocial theory, focusing on the influence of social interaction on self-development across one's lifespan.