There are many ways to play peek-a-boo. The classic version is to cover your face with your hands for a few seconds and then open your hands and cry, "Peek-a-boo!" The full-body version involves hiding from a baby (by ducking under her crib or behind the door) and then popping out and yelling, "Peek-a-boo!" Our favorite peek-a-boo game involves my husband clucking like a chicken and flapping his "wings" wildly on one side of the high chair. As he goes around to the back of the chair and out of sight he starts clucking much more quietly. Then he leaps out on the other side yelling, "Pauk pauk pauk!" (Guaranteed to crack up any baby.)
Babies love peek-a-boo for a variety of reasons. First, who wouldn't like seeing a grown-up act so smiley, energetic, and ridiculous? The peek-a-boo-playing adult turns his whole attention to a baby, and all babies love receiving undivided attention. Babies are also naturally attracted to human faces, and peek-a-boo puts your face close to his. Babies also love smiles, which are a large part of the game, and babies love the sound of a grown-up's voice. That sing-song "peek-a-boo" is fun for them to hear. Additionally, peek-a-boo is fun because of the element of surprise. A baby doesn't know exactly where or when a beloved face will peek through closed fingers. There is something positively thrilling to a baby about being surprised in this way.
Along with being fun, peek-a-boo also teaches babies the concept of object permanence, which occurs somewhere between the ages of 4 and 12 months. A baby learns that even if something is out of sight, it still exists.
Finally, a baby will quickly learn to play peek-a-boo back at you, covering his face with his hands or his head with a shirt. When he reveals himself and giggles he is making a joke — you thought I was gone but here I am! Ta-dah!
Adapted with permission from "Why Babies Do That: Baffling Baby Behavior Explained," by Jennifer Margulis, published by Willow Creek Press. 2005 by Jennifer Margulis. All rights reserved.