Which theorist proposed the theory of cognitive development?

• A. B.F. Skinner
• B. Lev Vygotsky
• C. Howard Gardner
• D. Jean Piaget

Answer: (D)

Jean Piaget is the theorist who proposed the theory of cognitive development. He proposed that children actively build their understanding of the world as they grow, and that thinking changes in distinct stages as they mature. The stages—sensorimotor, preoperational, concrete operational, and formal operational—map how children's reasoning evolves from basic actions driven by concrete experiences to more abstract, hypothetical thought. central to his idea are the mechanisms of assimilation and accommodation, which are the ways we adjust our mental schemes to fit new information, with equilibration guiding progress to higher levels of thinking. This perspective contrasts with other theories that focus on behavior (learning through consequences), social context, or different kinds of intelligences, which is why Piaget is associated specifically with the theory of cognitive development.