Which theorist is known for a stage-based theory of cognitive development that includes stages such as sensorimotor and formal operational?

• A. Constructivism
• B. Jean Piaget
• C. Behaviorism
• D. Social development

Answer: (B)

This question checks your knowledge of a stage-based view of how thinking develops, with clearly named stages. Jean Piaget is the thinker who proposed that children's cognitive abilities unfold through distinct, qualitative stages. In the sensorimotor stage, from birth to about two years old, infants learn through action and perception and develop object permanence. In the later formal operational stage, typically starting in adolescence, individuals begin to think abstractly and reason about hypothetical situations. Between these are the preoperational and concrete operational stages, each representing different ways of understanding and manipulating the world. Piaget also described how children move from one stage to the next through processes like assimilation and accommodation as they adjust to new experiences.

This makes him the best answer because the prompt points to a stage-based theory with specific stage names, which is uniquely associated with Piaget. Other options describe broader theories or approaches—behaviorism centers on observable behavior and conditioning, social development (Vygotsky) emphasizes social and cultural influences without a fixed stage sequence, and constructivism is a general learning philosophy rather than the specific stage framework Piaget created.