Piaget proposed four stages of cognitive development. Which set lists them?

• A. Sensorimotor, Preoperational, Concrete Operational, Formal Operational
• B. Sensorimotor, Preconceptual, Concrete, Abstract
• C. Reflex, Primary Circular, Secondary Circular, Tertiary
• D. Birth to 2, 2-7, 7-11, 11+

Answer: (A)

Piaget's theory describes four major stages of thinking that unfold from infancy through adolescence, each bringing new ways of understanding the world. The set that lists them as sensorimotor, preoperational, concrete operational, and formal operational is the standard sequence Piaget described.

In the sensorimotor stage, thinking is rooted in direct sensory and motor experiences. Object permanence emerges here—the understanding that things continue to exist even when they can’t be seen. As children move to the preoperational stage, around ages 2 to 7, language and symbolic play flourish, but reasoning remains largely egocentric and tied to appearances; they struggle with concepts like conservation. Then comes the concrete operational stage, roughly ages 7 to 11, where children begin to think logically about concrete objects and events, understand conservation, and see multiple perspectives in concrete situations. Finally, in the formal operational stage, starting around age 11, they develop abstract and hypothetical-deductive reasoning, enabling more systematic problem solving and planning.

The other options mix nonstandard labels or age groupings that don’t align with Piaget’s four established stages, so they don’t fit the traditional framework.