Psycho-social theory of development was propounded by :

CONCEPT: Erik Erikson's psychosocial theory of development proposes that personality develops across eight sequential stages spanning the entire lifespan, from infancy to old age. Each stage centers on a specific psychosocial crisis that arises from the individual's interaction with the social environment, and the way each crisis is resolved shapes personality growth. This theory extended earlier psychoanalytic ideas by shifting the focus from internal, biologically driven conflicts to social and cultural influences across the whole lifespan, not just early childhood.

APPLICATION: The question asks who propounded this stage-based, socially grounded theory of personality development. Erikson's eight stages include crises such as trust versus mistrust in infancy, autonomy versus shame and doubt in early childhood, identity versus role confusion in adolescence, and integrity versus despair in old age. Each stage builds on the previous one, and successful resolution of a crisis equips the individual to face the next stage of social and personal growth.

CROSS-CHECK: Comparing this against the other named psychologists confirms the identification. Thorndike is associated with connectionism and the laws of learning derived from trial-and-error experiments, not a stage theory of personality. Skinner is associated with operant conditioning and behaviour shaped by reinforcement, again unrelated to psychosocial stages. Hurlock is known for developmental-psychology textbooks synthesising research on childhood and adolescence rather than for originating a stage-based psychosocial theory. None of these three match the theory described in the question, confirming that the psychosocial theory of development is Erikson's original contribution.