Do Young 2-Year-Olds Understand Object Permanence?

Current research has consistently shown that children substantially younger than 2 years of age understand object permanence; i.e. infants have realistic expectations of where hidden objects should reappear, and they react with increased looking time to experimenter-manipulated violations of object permanence. However, new research has revealed that 2-year-olds' understanding of object permanence does not seem to transfer to active search tasks. Although infants look longer when an object moves behind a screen and is subsequently shown to have "magically" passed through a solid barrier, 2-year-olds do not search correctly for an object that has moved behind a panel of four doors and stopped at a barrier that is visible above the correct door. However, 2-year-olds do search flawlessly on a warm-up task in which the experimenter hides a stationary object behind one of the doors. Due to these conflicting results, I designed three search tasks to test whether the method of hiding the object affects young 2-year-olds' ability to successfully search. I used a simplified three-door apparatus with stationary objects in which children were allowed to search only one door per trial. In the Hide-3 search task, the experimenter opened a door, placed a toy in the doorway, and closed the door. In the Reveal-3 search task, all doors opened and closed simultaneously without the experimenter touching one door, and a toy was revealed already in place in a doorway. In the Reveal-2 search task, the experimenter hid the toy identically as in Reveal-3, except a hand puppet opened an incorrect door immediately after the toy was hidden, leaving two remaining doors for the child to search. If infants' and 2-year-olds' knowledge of a hidden object's location is activated in previous looking time experiments, then the puppet's incorrect search in Reveal-2 should facilitate their search performance relative to Reveal-3 by activating this knowledge. My results suggest that young 2-year-olds are not using knowledge of the hidden object's location to guide search. Instead, their performance is best explained by a utilization of alternate search strategies including imitation of the adult and salience differentials between search options. These results call into question a fundamental tenet of modern child psychology, that by 2 years of age children use their knowledge of object permanence to guide search under a variety of hiding and disappearance conditions.