Psychology Today | 12.10.2026 20:05
In Jean Piaget’s body of research on child development, the concept of “conservation” plays an important role. It refers to one’s ability to hold onto a critical but low-salience reality in the face of a high-salience, distorting event. The best example is probably Piaget’s experiment in which a child is shown two balls of clay and is asked to make sure they are exactly equal. Then one ball is transformed into a cigar shape, and the child is asked whether the ball has more clay, the cigar has more clay, or whether they are both the same. Until around age 5 or 6, a child will say the ball has more (because it is fatter) or the cigar has more (because it is longer), but typically not say that they are the same. Around age 6, when children reach the stage of “concrete operations,” they will say “the same.” They know that the shape looks different, but the mass is the same.
