According to Piaget, reversibility is mastered in which stage of development?

• A. Sensorimotor
• B. Preoperational
• C. Concrete Operational
• D. Formal Operational

Answer: (C)

Reversibility is about recognizing that a process can be undone to return to the starting state. In Piaget’s view, this ability shows up in the concrete operational stage, roughly ages 7 to 11. At this point children start to think logically about concrete transformations. They can imagine performing an action and then reversing it in their minds. For example, if you start with 7 cookies and give away 3, you have 4; if you then add 3 back, you’re back to 7. Or in math, they see that 7 minus 3 equals 4, and 4 plus 3 brings you back to 7. This ability helps with other logical skills like conservation and decentration, because they can consider relationships and changes in a reversible way. Earlier, in the sensorimotor and preoperational stages, reversibility isn’t yet mastered because actions aren’t mentally reversible. In the later formal operational stage, thinking expands to abstract and hypothetical ideas beyond concrete realities.