the philosophy of tickling

"Aristotle famously defined man as the rational animal (zoon echon logon), and as the political animal (zoon politikon). But there are also passages in his work that indicate another less remarked upon, though no less profound, definition. In Parts of Animals, he writes: “When people are tickled, they quickly burst into laughter, and this is because the motion quickly penetrates to this part, and even though it is only gently warmed, still it produces a movement (independently of the will) in the intelligence which is recognizable. The fact that human beings only are susceptible to tickling is due (1) to the fineness of their skin and (2) to their being the only creatures that laugh." Perhaps this notion of the “ticklish animal” was further elaborated in the second book of the Poetics, the lost treatise on comedy; indeed, the relationship between ticklish laughter and comic laughter remains an open question. Should tickling be investigated under the heading of comedy or of touch? Touch, Aristotle argues, is the most primary sense, and human beings are uniquely privileged in possessing the sharpest sense of touch thanks to the delicate nature of their skin. Though other animals have more advanced smell or hearing, “man’s sense of touch … excels that of all other animals in fineness.” We might view tickling as a side effect of the hyper-sensitivity of human touch. Our peculiar vulnerability to tickling is the price to be paid for more sophisticated and discriminating access to the world.

Why do people laugh when tickled? Why can’t you tickle yourself? Why are certain parts of the body more ticklish than others? Why do some people enjoy tickling and others not? And what is tickling, after all? In fact, it is not so easy to pin down the phenomenon, as a number of scientific studies attest. Here’s one attempt at a precise description: “Tickle may thus be finally defined as an intensely vivid complex of unsteady, ill-localized and ill-analyzed sensation, with attention distributed over the immediate sensory contents and the concomitant sensations reflexly evoked.” Coming at the end of some fifty pages of scientific investigation, such a vague and “ill-analyzed” conclusion might well disappoint. But perhaps there is a lesson to be learned here: any definition of tickle must be able to account for its lack of definition, its equivocal and evasive dynamism. Another researcher, Thomas Mintz, tried to render tickle’s shifting character by highlighting precisely this wandering mobility: “tickle—the itch that moves.” As Mintz argues, tickle, itch, and pain are very closely related on a neurological level, yet are interpreted by the brain as distinct phenomenological states: whereas an itch is experienced as a well-localized sensation that is “on” the skin and may be reached by scratching, a tickle consists in a shifting stream of stimuli that is “outside” us, and against which we push in convulsions and spasms. Pain, on the other hand, is “inside” and thus cannot be escaped. In an article now considered a classic in tickle studies, psychologists G. Stanley Hall and Arthur Allin distinguish two types of tickling: the first, which they name knismesis, is caused by a light movement across the skin, the feather-type of tickle, while the second, gargalesis, is provoked by the stronger pressure of poking and other movements. If the latter is more commonly associated with play and laughter, the former contains tickling’s true mystery:

Why is it that contact with the finest hair, wool, or cobweb evokes sensations that are not only exceedingly intense, but also very widely irradiated, and also provokes reflex movements that may be convulsive in their intensity, but when the same pressure, it may be of the same object and upon the same spot, is slightly increased, only the localized and moderate impression of touch is produced, with proper or no motor reactions?

Does not tickling violate the basic mechanism of cause and effect, the principle that every action entails an equal and opposite reaction? The tiniest stroking produces a wildly explosive response, while a more vigorous rubbing may hardly elicit any reaction at all. On the most stupid bodily level, there is something miraculous in the activity of tickling that seems to contravene the everyday experience of causality, turning us into spontaneous philosophical skeptics. It is as if the lived body were split into two: a practical body governed by regular principles and interactions, and an oversensitive flesh that, with the slightest tingle, is apt to plunge all coordination and mastery into spasmodic helplessness.

While scientific research has refuted Aristotle’s claim that tickling is a uniquely human privilege—not only has tickling been observed in our primate cousins, but scientists have recorded laughter-like ultrasonic chirping in tickled rats—it has confirmed his intuition regarding the importance of this seemingly marginal and unserious phenomenon. (An additional note on animal tickling: the most famously ticklish beast is no doubt the trout, which falls into a trance-like state when its underbelly is lightly rubbed. This has been known for ages; in Shakespeare’s Twelfth Night, Maria says, while planning to trick Malvolio, “Lie thou there; for here comes the trout that must be caught with tickling.”) Far from being a meaningless spasm, tickling is intimately bound up with human development and the sense of self. Such is the argument expounded by neuroscientist Robert Provine, who sees in tickling an important form of pre-verbal communication and an element in the creation of the distinction between self and other. A primal, neurologically programmed mode of interaction, tickling creates intimacy through a benign and playful aggression. And the well-known inability to tickle oneself serves an important role in educating the infant about the limits of its own bodily experience, poignantly signaling the difference between self-affection and being affected by the other.

Let us focus on one detail of Provine’s theory, a rather extravagant speculation. Linking tickling not only with humorous laughter but also with the prehistoric birth of comedy, Provine writes: “I forge recklessly into the paleohumorology fray, proposing my candidate for the most ancient joke—the feigned tickle. (Real tickling is disqualified because of its reflexive nature.) The ‘I’m going to get you’ game of the threatened tickle is practiced by human beings worldwide and is the only joke that can be told equally well to a baby human and a chimpanzee. Both babies and chimps ‘get’ this joke and laugh exuberantly.” Here we should underline the subtlety of Provine’s argument: ticklish laughter is not yet properly comic because it is too much of an automatic or neurological reaction. The joke first enters the scene with a distancing from reflex, when the tickling play is itself played with and made into a spectacle, when the suspended, not the real, gesture gets a laugh. The Ur-joke, the zero-degree of comedy, the pretend tickle may also be seen as a primordial manifestation of culture as a virtual space detached from immediate reflex and natural instinct.

Arthur Koestler anticipated this hypothesis in his wide-ranging study The Act of Creation:

Thus tickling a child will call out a wriggling and squirming response. But the child will laugh only—and this is the crux of the matter—if an additional condition is fulfilled: it must perceive the tickling as a mock attack, a caress in a mildly aggressive disguise. This explains why people laugh only when tickled by others but not when they tickle themselves. …

The mechanism is essentially the same as in comic impersonation: the tickler impersonates an aggressor, but is simultaneously known not to be one. It is probably the first situation encountered in life which makes the infant live on two planes at once, the first delectable experience in bisociation—a foretaste of pleasures to come at the pantomime show, of becoming a willing victim to the illusions of the stage, of being tickled by the horror-thriller.

In other words, tickling stands as the momentous entry-point into the universe of pretense, fiction, and simulation, or to cite the Greek term, mimesis. As we shall see, the relationship between tickling and theater is a profound one."