The model of humor development presented here reflects my own integration of the research findings on children's humor over the past 40 years or so (as well as some in the 1930s). For each of the stages described below, keep in mind that the age norms listed are offered only as general guidelines. Some children enter a given stage much earlier than others, although the age norms indicated do reflect an average age of onset. Most children continue to show the previous stage of humor long after the new form of humor first appears. Many will continue to show a given level of humor long past the end point of the age norms shown here. The age ranges shown reflect the peak of humor associated with that stage.
Since an infant can't tell you when something is or is not funny, how do you decide? The most obvious indicator, of course, is laughter. The only problem is that you can't even make this assumption with adults or older children. We all laugh at times when we don't find anything funny. We display nervous laughter and polite social laughter, for example. Sometimes we (and especially children) laugh just because we're excited.
Since children and adults laugh for reasons having nothing to do with humor, infants may well do the same. In fact, research on infants suggests that anything that is physiologically arousing to them, in a familiar or non-threatening situation, can trigger laughter. All parents know that bouncing the infant on your knee, quickly lowering her, or tickling are reliable causes of laughter. Many forms of tactile stimulation yield laughter. When my son was four months old, I could almost always elicit laughter by running my fingers up his stomach to his neck, making a high-pitched repetitive sound ("boop, boop, boop") along the way. Blowing "raspberries" on his stomach also usually worked, along with the traditional tickling in just the right places.
If humor really does involve altering (in a playful frame of mind) one's knowledge of the world, these examples clearly do not qualify as humor even though there is laughter, and the child seems to be in a playful frame of mind. So when does the child acquire a firm enough mastery in her understanding of parts of the world to experience distortion of it as funny?
In my view, the earliest form of humor is reacted to, rather than created by the infant. The infant's parents (or other primary attachment figure) are the most important part of her life. And since the parents are always around, their faces and behavior are the best-learned features of the infant's new world. Parents are also emotionally important to the infant, and are associated with satisfying basic needs. So it's not surprising that the earliest form of humor experienced by infants involves things the parents do.
By the age of six or seven months, you can find infants laughing at any unusual behavior of the parent. This might include something like: waddling like a penguin, making silly faces, sticking half a banana out of the mouth, making exaggerated animal sounds (barking, mooing, etc.), opening eyes very wide and bulging them out, sucking on a baby bottle, and so forth. (Surely you've tried these yourself!)
These things are funny to the infant precisely because they are recognized as being something beyond the usual pattern of behavior the parents have always shown. If the child's parents had always walked like penguins or had bananas sticking out of their mouths for the first six months of the child's life, these would be normal behaviors--and would not be funny.
When my son was 7 months old, holding a (clean) diaper under my nose was always funny. At 9 months, doing an exaggerated "Aaaaachoo!" after his own sneeze made him laugh hard. After the second or third time, I only had to do the "Aaaaah" part to get a laugh.
One mother noticed that her baby seemed to be having trouble getting milk from her bottle. Guessing that the nipple was clogged, she just popped the bottle into her own mouth to check it out. The baby laughed as soon as she saw the bottle in her mother's mouth.
Some examples of infant laughter from six to twelve months seem very similar to the laughter shown in the first six months, making it very difficult to know whether the laughter is reflective of humor or not. For example, the game of peek-a-boo is a popular source of laughter in Stage 1-- especially when it's done in an animated way, with a changed voice, or with the parent's face popping up in an unexpected or surprising place. The physiological arousal generated by peek-a-boo in itself makes it seem more like the laughter in Stage 0. But when elements of surprise and deviation from the usual (the altered voice or face appearing in an unexpected place) creep in, the experience comes closer to qualifying as humor.
At 8 or 9 months, my son was accustomed to the usual tune of "Twinkle Twinkle Little Star." One day I changed it by singing it faster and "rougher" (with a rough, throaty voice) when I got to the "how I wonder what you are" part. This was a good trigger for laughter for several weeks. The fact that it was a distortion of the familiar song suggests that this laughter was indicative of humor.
By the beginning of the second year, infants begin to show a new and exciting behavior-- pretend. For the first time, they start treating objects as if they were some other object. Not all pretend at this or any other age is humor, but it is this capacity for pretend that paves the way for the earliest humor created by the child.
Once the first birthday is passed, you may begin to see any of the following: putting a bowl, diaper, washcloth, etc., on her (or your) head as a hat; using any small long object as a toothbrush; or holding a shoe (or spoon) to her ear saying, "hello daddy." At 26 months, my son, who did not want to cooperate with an imminent diaper change, said,
"Don't want diaper changed. Give tape a new diaper." He then put a videotape onto the new diaper and laughed. At 20 months, I put his pants on my head (like a hat) as I was getting him ready for bed. He laughed, and when I took them off, he quickly handed them back to me and said, "Again, again!" with a big grin on his face.
A classic example of Stage 2 humor occurred at 24 months, when he took his shoes and put them on his hands, saying, "Look, shoes on." While he did not laugh this time, he had a mischievous smile on his face that reflected obvious pride in his insight.
At 22 months, my wife was brushing my son's teeth. He looked up with a glint in his eye and said, "Brush nose?" After a good laugh at his own witty remark, he followed with, "Brush ear?" In this case, he was using the correct object, but applying it to the wrong object.
While humor based on using objects in "wrong" ways continues throughout the peak of pretend behavior during the preschool years, budding language skills generate new opportunities for humor. After age two, parents increasingly hear, "What's that? What's that?" Two-year-olds are very excited by the realization that everything has a name, and they are thirsty sponges for every name you can give them. Since they have built into them a strong drive to play with all new skills, it's just a matter of time before they begin playing with the names of things. So what do they do? They give you the wrong name!
Many parents first see this new form of humor in the "Show me your nose" game. Even if you've always played the game straight yourself, the day always arrives when you say, "Show me your nose," and your child gets a mischievous grin on her face and points to . . . her ear! She may or may not laugh, but there's no doubt that this is pretty funny to her.
Once this insight is achieved-- that it's hilarious to call something a name you know is wrong-- every object or person is fair game. Cats will be called dogs, mommy will be called daddy, daddy will be called the child's own name, and so on. It's all just too funny!
My son loved to screw up words in familiar songs. One day, at 26 months, he sang a new version of a song he had been singing the right way for months. He sang, "Head, shoulders, knees and mommy," and laughed. In subsequent days, "mommy" was replaced by "yogurt," "toast," Telletubbies," and more. At about the same time, the alphabet song was transformed to "A, B, C, D, E, F, alligator," again accompanied by great guffaws.
At 26 months, he also picked up a toy dog and said, "Here kitty, kitty." While he laughed at this, this was also the age at which he began giving answers he knew to be wrong-- without laughing. For example, one day his mom said, "Where'd the yogurt go? Into your mouth and down to your tummy." His immediate reaction was, "No, in the light!" Only a slight grin gave away the fact that he intentionally distorted the obvious. Was this the beginning of a dry sense of humor?
Many (but not all) children are especially drawn to a specific form of mislabeling objects and events-- giving the exact opposite of the word known to be correct. So a hat that's too big is said to be "too small." If you say a toy is upstairs, she says it's downstairs. If you say, "Be careful, that pan is hot!" she says, "No, it's cold!" If you say, "OK, it's time to go," she says, "No, it's time to stay."
In many cases, this quick reversal of whatever you say is just another variation of the negativity that toddlers show as part of their first step toward independence. In other cases, it's clearly designed to be funny. At 29 months, while playing "Ring Around the Rosie," my son sang, "Ashes, ashes, we all fall up!" His own laughter left no doubt that this was a joke.
Several new forms of humor emerge by the end of the third year. Simply calling things by the wrong name continues to be funny after age two, but a new way of playing with words appears around age three (as early is 2 _ in some children). Children become very attuned to the way words sound, and begin playing with the sounds themselves. This often takes the form of repeating variations of a familiar word over and over, such as "daddy, faddy, paddy," or "silly, dilly, willy, squilly."
Sound play may also show up by altering the sound of a single word in an otherwise normal sentence, such as "I want more tato-wato-chatos" for potatoes. Complete nonsense words may also appear, as in "Let's all spooty-dotty-ditty-bip." In the second half of his third year, my son enjoyed nonsense words so much that we often had verbal jousting sessions in which we would take turns hurling nonsense sounds at each other. This was great fun off and on for several months. The well-known cartoon character Sylvester the Cat utilizes this source of fun in young children with his familiar distortion of speech: "I taut I taw a putty tat."
In addition to playing with the sounds of words, most (but not all) three-year-olds also start putting real words together in nonsensical combinations known to be wrong. Their budding linguistic competence tells them that words are put together in certain combinations, but not others. So we would expect them to find great fun in simply putting words together in ways known to be silly or wrong. These combinations appear to simply be another way of distorting the known properties of objects, as described in stage 4c.
The following are typical of this kind of humor:
"I want more tree milk."
"I have a mail box flower."
"I want more potato (dirt, guitar, etc.) juice."
"I want a peanut butter chair."
My wife and I were especially delighted the day he changed a familiar game we played. My wife or I would sing, "peanut, peanut butter" and he would chime in, "and jelly." Sometimes he would start out, and we would say "and jelly." We would repeat this 5-10 times before he was ready to move on to something else. One day, at 28 months, instead of saying, "and jelly," he said, "and refrigerator" (and laughed). In the days that followed, we heard "and light," "and daddy," "and tree," etc. Anything that he happened to see at the moment was fair game.
We also sang (to the same tune) "maca, macaroni," and his part was to say, "and cheese." Again, sometimes he would start and sometimes we would. Within a few days of the first occurrence of the above example, he said, "and shoes," "and bib," "and TV," instead of "and cheese," again with beaming eyes. Most kids show this great delight when they create something they know to be at odds with reality.
By age three, children go beyond knowing that things have names to an understanding that these names apply to classes or categories of objects that share certain key features. Jean Piaget referred to this as the onset of conceptual thinking. Even though the child has been using the word "dog" correctly in referring to many different dogs, this is the first point at which "dog" is thought of as a category of animals with certain shared features. This includes barking (vs. meowing or mooing), a certain range of differences in size, color, hair length, tail length, etc., four feet, no hands, two ears, etc. A new form of humor, then, can be expected to involve a violation of any of these features that define "dog" in the child's mind.
Stage 3 humor still occurs at this point, but most children find it much funnier to distort some aspect of their new conceptual understanding of objects than to simply call them by the wrong name. The examples below illustrate the most common forms of humor at this stage, although they are not exhaustive of the types that appear:
Adding features that don't belong
1) A dog's head on a man's body.
2) A tree with cakes growing on it.
3) Cats and dogs coming from clouds, instead of rain.
Removing features that do belong
1) A cat with no tail or legs.
2) A car with no wheels.
3) A person with no nose or ears.
Changing the shape, size, location, color, length, etc. of familiar things
1) A person with a square head, polka dot ears, or eyes in the wrong place.
2) Exaggerated features, such as a long neck, big ears, enormous or very pointy nose, etc.
3) Eyes and ears in reversed places. (Try it with Mr. Potato Head.)
4) Wrong proportions (e.g., real long arms and short legs, a large man with a tiny hat (or vice versa), enormous clown feet, etc.
Incongruous or impossible behavior (as in Far Side cartoons)
1) A cow on roller skates or sitting in a tree whistling like a bird.
2) A baby pushing a carriage containing an adult in diapers, sucking on a bottle.
3) A dog playing a piano and singing.
Even though children laugh at these things, either created by themselves, seen on TV, or read in books, the firmness of their level of confidence in what is and is not possible is often seen in their questions to parents. "Daddy, pigs can't really fly, can they?" "Lions don't read books, do they?" "Cars can't drive themselves, can they?" Many children enjoy pretending to think that you may also be confused by what's possible, so they tell you, "It's just pretend daddy. Trains can't jump." If you're like many parents, you will feign confusion about just what animals, trains, etc. can and cannot do-- to the child's great delight.
By age five (and sometimes earlier), most children become interested in the verbal humor shared by older children around them. They hear other kids ask puzzling questions and then give what appear to be very arbitrary answers that are followed by laughter. So they simply imitate what they hear other kids doing. This can trick you into thinking the riddles they tell are understood, because they are told correctly. But all parents have also heard their kindergartners tell such riddles or knock-knock jokes as:
What did the cat say to the mouse? I'm gonna eat you up!
Knock-knock. Who's there? Nobody's home!
Knock-knock. Who's there? Piece of bread. Piece of bread who?
Piece of bread . . . Want another piece of bread?
When five- and six-year-olds tell these riddles and jokes, they typically laugh as soon as they tell them. Parents can genuinely share this laughter--but for a very different reason. Children's off-the-wall answers to their own riddles are very funny, because they make no sense at all. Kids don't really understand the riddles at this age, so their answers seem just as good as those older kids give. By the age of 6 or 7, they begin to understand the double meanings involved in puns (because of the onset of concrete operational thinking, as described by Piaget), and these "off-the-wall" answers gradually disappear.
The fact that children still have occasional accidents in bowel and bladder control at this age makes this theme emotionally salient. So you can also expect to hear such riddles as this: Knock-knock. Who's there? Pee. Pee who? Pee-pee in your pants! (Ha, ha, ha!)