Piaget’s Cognitive Development Theory – Children go through 4 stages: sensorimotor (0–2), preoperational (2–7), concrete operational (7–11), and formal operational (12+). Each stage shows how thinking evolves from basic to abstract.Erikson’s Psychosocial Development Theory – 8 stages focused on social and emotional development, like trust vs. mistrust (infancy) and identity vs. role confusion (teen years).Vygotsky’s Sociocultural Theory – Emphasizes the role of social interaction and language in learning. Introduced the “Zone of Proximal Development.”Skinner’s Behaviorism – Learning is shaped by reinforcement and punishment (stimulus-response).Bandura’s Social Learning Theory – Children learn through observation, imitation, and modeling (e.g., doll experiment).