The things that children find funny tell us a great deal about their level of development and what is on their minds. There is a connection between the 2-year-old who bursts into a fit of giggles upon hearing the nonsense phrase “bottle, battle, bittle” and the young adolescent who laughs at the bawdiness of an off-color joke.
The specific things children laugh at tell us which developmental tasks they are struggling with. That is a pattern that runs throughout childhood. It explains why 3-year-olds, who are often still mastering toilet training, are enthralled by “bathroom” humor while 7-year-olds, who no longer consider toilet-training an issue, think such jokes are just stupid.
Laughing and smiling are among the most human of behaviors. A twelve-hour-old infant will shape his mouth into what looks like a smile at the smell of a banana or other sweet food. Our nervous systems appear to be wired to make us smile. No learning or imitation is needed. True laughter, which is more complex, does not appear until a few months later.
Children learn some very complex things during their first dozen months, starting with the realization that they are separate individuals from their parents. Soon they begin to understand that objects and people exist, even when they are out of sight. This is a very profound realization. When Mom leaves the room, she is doing something else and will eventually return. A toy that is placed behind a cardboard barrier can be obtained if you reach around or over the barrier. By reaching for that toy, the child shows that he understands the concept that people and things have a physical existence even when they are not seen. (The first time I tried this test on my 6-month-old son he tried to eat the cardboard barrier!)
Few things elicit as much laughter from a 1-year-old child as a game of peekaboo. Yet a 6-month-old will barely respond to the game, and a 6-year-old will find it boring. Laughing at peekaboo is a marker for a certain level of intellectual development. The intensity of the 1-year-old’s laughter tells you that he or she “gets it”: That’s my mother behind those hands! It is a realization that would have eluded the child only a few weeks or months earlier.
The game of peekaboo still works if done in silence. Watching the mother’s face disappear behind her hands excites the child, who knows that the mother is back there and predicts that she will reappear. It is a tense situation. When the mother’s face comes back into view, the child is relieved and laughs with excitement. What was scary is now fun, for the child can predict the future. If the mother keeps her face hidden for too long, however, the child’s tension will turn to fear, and the child will cry.
Once children understand a concept, they take great joy in playing with it. Two-year-olds who are beginning to master the intricacies of language will giggle uncontrollably when they hear a combination of words and nonsense syllables. They understand that the nonsense syllables are different from the words. The sounds are out of place. They are funny.
Other things that are out of place will get the same laughter from 2-year-olds, for they are learning that there is an order to the world. Placing a sock on a foot is not funny. Placing it on an ear is hysterical to 2-year-olds because they realize that it does not belong there. They share their mastery of that knowledge through laughter.