According to Jean Piaget's theory of cognitive development, the concept of 'conservation'—the understanding that changing an object's appearance, shape, or color does not alter its quantity, mass, or volume—is a primary characteristic of which stage?

According to Jean Piaget's theory of cognitive development, the development of the ability of 'conservation' is a key characteristic of the Concrete Operational Stage (approximately 7 to 11 years of age).

During this stage, a child understands that altering the shape of a substance (such as pouring liquid from a wide container into a tall one) changes its appearance, but its overall quantity or volume remains constant.

Key Features of this Stage:

• Conservation: Recognizing that quantity does not change with physical transformation.
• Decentration: The ability to focus on multiple aspects of a problem rather than just one.
• Reversibility: Understanding that actions can be reversed.