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A Fresh Look at the Infancy of Our Laughter

How our ever-changing sense of humor begins in the first few months of life.

Key points

  • The Mutual Vulnerability Theory, like all explanations for why we laugh, must be able to account for variations in our laugh response.
  • It suggests that our tendency to regard a trait as a “vulnerability” rather than “normal” or a “deficiency” will vary depending on experience.
  • Such evaluations begin to take shape in early infancy, influencing our sense of humor throughout childhood and beyond.
Keira Burton/Pexels
Source: Keira Burton/Pexels

There are few sounds as delightful and engaging as the laughter of an infant. In that place and at that moment, all is right with the world.

We know, however, that very young children cannot appreciate many of the things that will amuse them later in life. For those interested in understanding why people have varying responses to potentially amusing stimuli, it makes sense to begin with individual, age-related differences. So let’s begin with a look at what cultivates laughter in the first few months of life.

According to the Mutual Vulnerability Theory, the tendency to find certain traits or behaviors amusing requires our perceiving them as “vulnerabilities” as opposed to something we would consider either “normal” or seriously “deficient”. This requires an understanding of the goals being pursued, how they are best reached, and what actions are likely to result in significant delays or outright failure.

Obviously, our understanding of vulnerability, both our own and others’, changes significantly as we grow from infant to adult. Notions about how well we (or others) are maintaining our physical selves, managing emotions, perceiving and processing information, and communicating and interacting with cohorts are always colored by one’s own relative stage of cognitive development. In most healthy individuals, this strongly correlates with age.

Here are some personal observations that may help illustrate this concept.

The Laughter of Infancy

Newborns don’t express their amusement with adult-style laughter. Although most scholars agree that laughter is an innate behavior, the mature acoustic form is not available to the infant until the child has attained greater vocal chord development and diaphragm control. Because adult-like laughter doesn’t begin until around the third or fourth month of life, studies of amusement in infancy possess inherent limitations. That said, in these first few months, smiles, breathy or gurgling exhalations, and/or mild abdominal spasms are recognized by most as equivalent antecedents.

For young infants, an understanding of vulnerability seems to be restricted in two main ways. First, their awareness is initially confined to “first-person” events—they perceive their own vulnerability before that of other individuals. And second, they’re primarily concerned with physical vulnerabilities (e.g., tactile stimuli, body orientation and mobility, continuity of sensory input) or those which deal with basic emotions (e.g., disgust, joy, and excitement), their own and then others’, as revealed in the expressions and nonverbal vocalizations.

In this period, gently touching an infant’s more sensitive areas (sides, feet, neck, and back), raising them up in the air, blowing a puff of air in their face, or swinging them gently are common ways to solicit laughter. These and similar stimuli all play on infants’ innate understanding of their own physical vulnerability. Caretakers often accompany these tactics with smiles, breathy vocalizations, and laughter itself to signal a “play frame” (Gruner, 1997). Over time, these behaviors will become the cues children will use to distinguish mock attacks from true aggression—the reasons they will not scream in horror as caretakers threaten to “eat” them up or “drop” them from a precarious height. In turn, smiles and breathy exhalations on the child’s part let adults know they’re not feeling truly threatened but rather mildly vulnerable. Smiles, in effect, act as a nod of consent for continued (unforced) contact.

As the first couple of months pass, infants become increasingly familiar with the rules that govern their social, in addition to physical, environment. Games like “peek-a-boo” are perceived as short, playful acts of departure and arrival by the caretaker. Disappear for a few seconds and the child feels slightly threatened; a quick return is marked with smiles and perhaps self-lifting laughter. If the caretaker vanishes for a few minutes, on the other hand, the infant may feel threatened to the point of frustration.

From First Person to Second

During this stage, children begin to develop a rudimentary ability to recognize the vulnerabilities of familiar individuals. They are, for example, becoming sufficiently acquainted with facial expressions to distinguish “normal” ones from abnormal, “funny” ones. They’re better able to interpret the caretaker’s emotional state and manipulate others’ behaviors through their own.

As time goes on, infants gain an improved understanding of the “rules” that govern bodily movement. They are better at distinguishing normal from unusual locomotion in others. The same sense of amusement comes when a child’s physical progress is hampered or controlled as with short, playful restraint, being lifted over the caretaker’s head, or having their arms or legs manipulated by another individual.

Between the ages of three and six months, children begin to develop an understanding of the rules of social interaction—concepts of taking turns, sharing, and dominance. With progressively greater social experience, they attain an improved understanding of communication norms and, as such, the ability to recognize deviations. Adults can thus solicit lifting laughter from children using ill-timed or strange vocalizations (squeaks, whistles, grunts, lip smacks, and the like). Toys, pets, and musical instruments also produce various sounds that are novel and subject to interpretation.

Despite their cognitive limitations, infants clearly show the ability to recognize their own vulnerabilities, interpret (to a lesser extent) those of others, and communicate through smiles and laughter. They form bonds of affection and trust, learn the basic guidelines of social interplay, and form internal representations of what is normal and what is not. Laughter and humor help to define a zone of familiarity and comfort within which children are encouraged to explore, through trial and error, their physical and social worlds.

This YouTube video should put a smile on your face as it demonstrates some of the ideas presented here.

This post draws from my book, Why We Laugh: A New Understanding.

© John Charles Simon


Gruner, C. R. (1997). The Game of Humor: A Comprehensive Theory of Why We Laugh. New Brunswick, New Jersey: Transaction Publishers.

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