A researcher hides a 10-month-old infant's toy under cloth A repeatedly. When the toy is then visibly placed under cloth B, the infant searches under cloth A again. According to Piaget, this behavior demonstrates:

• A Complete object permanence, placing the infant in the preoperational stage
• B Egocentrism, characteristic of the formal operational stage
• C Lack of deferred imitation, typical of the concrete operational stage
• D The A-not-B error, showing object permanence is still incompletely developed ✓

Explanation

Searching where the object was previously found despite seeing it moved elsewhere is the classic A-not-D error of Piaget's sensorimotor stage, seen around 8 to 12 months. It shows the infant has partial object permanence but has not yet attained the full concept, which matures by about 18 months. Egocentrism belongs to the preoperational stage and logical operations to concrete operations, so the other options misplace both the error and the stage.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.