Your Child's Brain in Week 99
While your toddler might still occasionally play peek-a-boo with you or Grandma, hide and seek now reigns as Best Game Ever. (You'll remember that last year, as your baby was getting the hang of object permanence, games involving disappearance fascinated him.)
Until recently, your child would look in just one spot for a hidden person or object. Now, if you move from place to place, he'll keep looking for you—he knows you're somewhere, and he's not stumped when you're no longer behind the sofa where he'd first spotted you peeking at him. He'll search for you in the bathroom, behind a chair, in a closet….
What the Research Shows
Researchers set children between 12 and 18 months old on a chair at a table. On the table was an apple, and on each side of the apple was a piece of cloth. Each child would watch as the researcher covered the apple with one cloth, and in turn, he or she would happily uncover the apple, playing peek-a-boo with it.
Then, while distracting the child, the researcher would quickly put the apple under the other cloth. When the child's attention was brought back to the table, he or she was perplexed to find that the apple had moved, and remained perplexed, not looking under the other cloth or elsewhere.
When the same study was conducted with children aged 18 to 24 months, the results indicated that at around this time, an intellectual shift occurs: The older toddlers did look for the apple after being distracted, and were delighted to find it under the other cloth. What this and similar studies show us is that around the year-and-a-half mark, a child realizes an object still exists even when its hidden location changes—it must be somewhere, and he's determined to find it.