Piaget - Stage 1 - Sensorimotor stage : Object Permanence NARRATOR 1: New babies aren't quite sure what happens to objects when they leave their site. Sky's mom keeps disappearing and reappearing. No wonder peek a boo is so much fun. During their first year however, infants will learn an important concept, object permanence. Everything has a life of its own, even if it is out of sight. NARRATOR 2: At Maya's age, babies know to look for the object, but they might not have everything else straight. 10-month-old Simon is about to make a classic mistake, known as the A not B error. Although he watched us place the toy plane under the white cloth, he'll look for it where he last found it, not where he watched us hide it. If a one-year-old can't find an object they want right away, they're likely to give up looking.