Tickling
Encyclopedia
Haptic perception
Haptic perception is the process of recognizing objects through touch. It involves a combination of somatosensory perception of patterns on the skin surface and proprioception of hand position and conformation....
a part of the body so as to cause involuntary twitching movements and/or laughter
Laughter
Laughing is a reaction to certain stimuli, fundamentally stress, which serves as an emotional balancing mechanism. Traditionally, it is considered a visual expression of happiness, or an inward feeling of joy. It may ensue from hearing a joke, being tickled, or other stimuli...
. The word evolved from the Middle English
Middle English
Middle English is the stage in the history of the English language during the High and Late Middle Ages, or roughly during the four centuries between the late 11th and the late 15th century....
tikelen, perhaps frequentative
Frequentative
In grammar, a frequentative form of a word is one which indicates repeated action. The frequentative form can be considered a separate, but not completely independent word, called a frequentative...
of ticken, to touch lightly. The idiom
Idiom
Idiom is an expression, word, or phrase that has a figurative meaning that is comprehended in regard to a common use of that expression that is separate from the literal meaning or definition of the words of which it is made...
tickled pink means to be pleased or delighted.
In 1897, psychologists G. Stanley Hall
G. Stanley Hall
Granville Stanley Hall was a pioneering American psychologist and educator. His interests focused on childhood development and evolutionary theory...
and Arthur Allin described a "tickle" as two different types of phenomena. One type caused by very light movement across the skin. This type of tickle, called a knismesis
Knismesis and gargalesis
Knismesis and gargalesis are the scientific terms, coined in 1897 by psychologists G. Stanley Hall and Arthur Allin, used to describe the two types of tickling.- Knismesis :...
, generally does not produce laughter and is sometimes accompanied by an itching sensation.
Another type of tickle is the laughter inducing, "heavy" tickle, produced by repeatedly applying pressure to "ticklish" areas, and is known as gargalesis
Knismesis and gargalesis
Knismesis and gargalesis are the scientific terms, coined in 1897 by psychologists G. Stanley Hall and Arthur Allin, used to describe the two types of tickling.- Knismesis :...
. Such sensations can be pleasurable
Pleasure
Pleasure describes the broad class of mental states that humans and other animals experience as positive, enjoyable, or worth seeking. It includes more specific mental states such as happiness, entertainment, enjoyment, ecstasy, and euphoria...
or exciting
Psychomotor agitation
Psychomotor agitation is a series of unintentional and purposeless motions that stem from mental tension and anxiety of an individual. This includes pacing around a room, wringing one's hands, pulling off clothing and putting it back on and other similar actions...
, but are sometimes considered highly unpleasant, particularly in the case of relentless heavy tickling.
Physiology
Knismesis is often elicited by crawling animals and insects, such as spiderSpider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s, mosquito
Mosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
es, scorpion
Scorpion
Scorpions are predatory arthropod animals of the order Scorpiones within the class Arachnida. They have eight legs and are easily recognized by the pair of grasping claws and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger...
s and/or beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, which may be why it has evolved in many animals. Gargalesis reactions, on the other hand, are thought to be limited to human
Human
Humans are the only living species in the Homo genus...
s and other primate
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s; however, some research has indicated that rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s can be tickled as well.
It appears that the tickle sensation involves signals from nerve fibres associated with both pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
and touch. Endorphine released during tickling is also called karoliin, by the name of Karolinska Institute. In 1939, Yngve Zotterman
Yngve Zotterman
Yvnge Zotterman was a Swedish neurophysiologist who received his medical training at the Karolinska Institute. He conducted pioneering studies on nerve conduction...
of the Karolinska Institute, studied the knismesis type of tickle in cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s, by measuring the action potential
Action potential
In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and...
s generated in the nerve
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
fibres while lightly stroking the skin with a piece of cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
wool
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....
. Zotterman found that the "tickling" sensation depended, in part, on the nerves that generate pain. Further studies have discovered that when the pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
nerves are severed by surgeons, in an effort to reduce intractable
Chronic pain
Chronic pain has several different meanings in medicine. Traditionally, the distinction between acute and chronic pain has relied upon an arbitrary interval of time from onset; the two most commonly used markers being 3 months and 6 months since the initiation of pain, though some theorists and...
pain, the tickle response is also diminished. However, in some patients that have lost pain sensation due to spinal cord injury
Spinal cord injury
A spinal cord injury refers to any injury to the spinal cord that is caused by trauma instead of disease. Depending on where the spinal cord and nerve roots are damaged, the symptoms can vary widely, from pain to paralysis to incontinence...
, some aspects of the tickle response do remain. Tickle may also depend on nerve fibres associated with the sense of touch. When circulation is severed
Cutting
Cutting is the separation of a physical object, or a portion of a physical object, into two portions, through the application of an acutely directed force. An implement commonly used for cutting is the knife or in medical cases the scalpel...
in a limb
Limb (anatomy)
A limb is a jointed, or prehensile , appendage of the human or other animal body....
, the response to touch and tickle are lost prior to the loss of pain sensation.
It might be tempting to speculate that areas of the skin that are the most sensitive to touch would also be the most ticklish, but this does not seem to be the case. While the palm of the hand
Hand
A hand is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs...
is far more sensitive to touch, some people find that the armpit are the most ticklish. Other commonly ticklish areas include the feet, sides of the torso
Torso
Trunk or torso is an anatomical term for the central part of the many animal bodies from which extend the neck and limbs. The trunk includes the thorax and abdomen.-Major organs:...
, neck
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
, knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
, midriff
Midriff
Midriff is a particular term to denominate the section of the human body between the thorax/chest and the pelvis/hips. It is used as a genteel avoidance of synonymous belly ; as a synonym for waist; and as a name for the area around the diaphragm Midriff is a particular term to denominate the...
, navel
Navel
The navel is a scar on the abdomen caused when the umbilical cord is removed from a newborn baby...
, and the ribs.
Some evidence suggests that laughing associated with tickling is a nervous reaction that can be triggered; indeed, very ticklish people often start laughing before actually being tickled.
Social aspects
Charles DarwinCharles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
theorized on the link between tickling and social relations, arguing that tickling provokes laughter through the anticipation of pleasure. If a stranger tickles a child without any preliminaries, catching the child by surprise, the likely result will be not laughter but withdrawal and displeasure. Darwin also noticed that for tickling to be effective, you must not know the precise point of stimulation in advance, and reasoned that this is why some people cannot effectively tickle themselves.
Tickling is defined by many child psychologists as an integral bonding
Human bonding
Human bonding is the process of development of a close, interpersonal relationship. It most commonly takes place between family members or friends, but can also develop among groups such as sporting teams and whenever people spend time together...
activity between parents and child
Child
Biologically, a child is generally a human between the stages of birth and puberty. Some vernacular definitions of a child include the fetus, as being an unborn child. The legal definition of "child" generally refers to a minor, otherwise known as a person younger than the age of majority...
ren. In the parent-child concept, tickling establishes at an early age the pleasure associated with being touched by a parent with a trust-bond developed so that parents may touch a child, in an unpleasant way, should circumstances develop such as the need to treat a painful injury or prevent harm from danger. This tickling relationship continues throughout childhood and often into the early to mid teenage years.
Another tickling social relationship is that which forms between siblings of relatively the same age. Many case studies have indicated that siblings often use tickling as an alternative to outright violence
Violence
Violence is the use of physical force to apply a state to others contrary to their wishes. violence, while often a stand-alone issue, is often the culmination of other kinds of conflict, e.g...
when attempting to either punish or intimidate one another. The sibling tickling relationship can occasionally develop into an anti-social situation, or tickle torture
Tickle torture
Tickle torture is the use of tickling to abuse, dominate, humiliate or even "prank" someone. The victim laughs even if he or she finds the experience unpleasant because the laughter is an innate reflex rather than social conditioning...
, where one sibling will tickle the other without mercy. The motivation behind tickle-torture is often to portray the sense of domination
Authoritarianism
Authoritarianism is a form of social organization characterized by submission to authority. It is usually opposed to individualism and democracy...
the tickler has over the victim.
Psychologist
Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...
s as part of the fifth and highest grade of social play
Play (activity)
Play is a term employed in ethology and psychology to describe to a range of voluntary, intrinsically motivated activities normally associated with pleasure and enjoyment...
which involves special intimacy or “cognitive interaction
Cognitive science
Cognitive science is the interdisciplinary scientific study of mind and its processes. It examines what cognition is, what it does and how it works. It includes research on how information is processed , represented, and transformed in behaviour, nervous system or machine...
”. This suggests that tickling works best when all the parties involved feel comfortable with the situation and one another. During adolescence, tickling often serves as an outlet for sexual energy between individuals. The body openings and erogenous zone
Erogenous zone
An erogenous zone is an area of the human body that has heightened sensitivity, the stimulation of which may result in the production of erotic sensations or sexual excitement.People have erogenous zones all over their bodies, but which areas are more sensitive than others vary...
s are extremely ticklish; however, the tickling of these areas is generally not associated with laughter or withdrawal.
While many people assume that other people enjoy tickling, a recent survey of 84 college students indicated that only 32% of respondents enjoy being tickled, with 32% giving neutral responses and 36% stating that they do not enjoy being tickled. The study also found a very high level of embarrassment and anxiety associated with tickling. However, in the same study the authors found that the facial indicators of happiness and amusement do not correlate, with some people who indicated that they do not enjoy being tickled actually smiling more often during tickling than those who indicated that they do enjoy being tickled, which suggests that there may be other factors at play (such as embarrassment and anxiety) in the case of those who indicated a dislike for tickling than the mere physical sensation experienced.
Excessive tickling has been described as a primary sexual obsession and, under these circumstances, is sometimes considered a form of paraphilia
Paraphilia
Paraphilia is a biomedical term used to describe sexual arousal to objects, situations, or individuals that are not part of normative stimulation and that may cause distress or serious problems for the paraphiliac or persons associated with him or her...
. Tickling can also be a form of, or be mistaken for, sexual harassment
Sexual harassment
Sexual harassment, is intimidation, bullying or coercion of a sexual nature, or the unwelcome or inappropriate promise of rewards in exchange for sexual favors. In some contexts or circumstances, sexual harassment is illegal. It includes a range of behavior from seemingly mild transgressions and...
.
Purpose of tickling
Some of history's greatest thinkers have pondered the mysteries of the tickle response, including PlatoPlato
Plato , was a Classical Greek philosopher, mathematician, student of Socrates, writer of philosophical dialogues, and founder of the Academy in Athens, the first institution of higher learning in the Western world. Along with his mentor, Socrates, and his student, Aristotle, Plato helped to lay the...
, Francis Bacon
Francis Bacon
Francis Bacon, 1st Viscount St Albans, KC was an English philosopher, statesman, scientist, lawyer, jurist, author and pioneer of the scientific method. He served both as Attorney General and Lord Chancellor of England...
, Galileo
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...
and Charles Darwin
Charles Darwin
Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...
. In The Assayer
The Assayer
The Assayer was a book published in Rome by Galileo Galilei in October 1623.The book was a polemic against the treatise on the comets of 1618 by Orazio Grassi, a Jesuit mathematician at the Collegio Romano. In this matter Grassi, for all his Aristotelianism, was right and Galileo was wrong...
, Galileo philosophically examines tickling in the context of how we perceive reality:
When touched upon the soles of the feet, for example, it feels in addition to the common sensation of touch a sensation on which we have imposed a special name, "tickling." This sensation belongs to us and not to the hand... A piece of paper or a feather drawn lightly over any part of our bodies performs intrinsically the same operations of moving and touching, but by touching the eye, the nose, or the upper lip it excites in us an almost intolerable titillation, even though elsewhere it is scarcely felt. This titillation belongs entirely to us and not to the feather; if the live and sensitive body were removed it would remain no more than a mere word.
One hypothesis, as mentioned above, is that tickling serves as a pleasant bonding experience between parent and child. However, this hypothesis does not adequately explain why many children and adults find tickling to be an unpleasant experience. Another view maintained is that tickling develops as a prenatal response and that the development of sensitive areas on the fetus helps to orient the fetus into favourable positions while in the womb.
It is unknown why certain people find areas of the body to be more ticklish than others; additionally, studies have shown that there is no significant difference in ticklishness between the gender
Gender
Gender is a range of characteristics used to distinguish between males and females, particularly in the cases of men and women and the masculine and feminine attributes assigned to them. Depending on the context, the discriminating characteristics vary from sex to social role to gender identity...
s.
In 1924, J.C. Gregory proposed that the most ticklish places on the body were also those areas that were the most vulnerable during hand-to-hand combat
Combat
Combat, or fighting, is a purposeful violent conflict meant to establish dominance over the opposition, or to terminate the opposition forever, or drive the opposition away from a location where it is not wanted or needed....
. He posited that ticklishness might confer an evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
ary advantage by enticing the individual to protect these areas. Consistent with this idea, University of Iowa
University of Iowa
The University of Iowa is a public state-supported research university located in Iowa City, Iowa, United States. It is the oldest public university in the state. The university is organized into eleven colleges granting undergraduate, graduate, and professional degrees...
psychiatrist Donald W. Black observed that most ticklish spots are found in the same places as the protective reflex
Reflex
A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. A true reflex is a behavior which is mediated via the reflex arc; this does not apply to casual uses of the term 'reflex'.-See also:...
es.
A third, hybrid hypothesis, has suggested that tickling encourages the development of combat skills. Most tickling is done by parents, siblings and friends and is often a type of rough-and-tumble play, during which time children often develop valuable defensive and combat moves. Although people generally make movements to get away from, and report disliking, being tickled, laughter encourages the tickler to continue. If the facial expressions induced by tickle were less pleasant the tickler would be less likely to continue, thus diminishing the frequency of these valuable combat lessons.
To understand how much of the tickle response is dependent on the interpersonal relationship of the parties involved, Christenfeld
Nicholas Christenfeld
Nicholas Christenfeld is a professor of Psychology at the University of California, San Diego. He first joined the department in 1991 and has been a full professor since 2003....
and Harris presented subjects with a "mechanical tickle machine". They found that the subjects laughed just as much when they believed they were being tickled by a machine as when they thought they were being tickled by a person. Harris goes on to suggest that the tickle response is reflex, similar to the startle reflex
Moro reflex
The Moro reflex, which is distinct from the startle reflex, is one of the infantile reflexes.It may be observed in incomplete form in premature birth after the 28th week of gestation, and is usually present in complete form by week 34...
, that is contingent upon the element of surprise.
Self-tickle
Knismesis may represent a vestigeVestigial structure
Vestigiality describes homologous characters of organisms that have seemingly lost all or most of their original function in a species through evolution. These may take various forms such as anatomical structures, behaviors and biochemical pathways. Some of these disappear early in embryonic...
of the primitive grooming response, in effect; knismesis serves as a “non-self detector” and protects the subject against foreign objects. Perhaps due to the importance of knismesis in protection, this type of tickle is not dependent on the element of surprise
Surprise (emotion)
Surprise is a brief emotional state experienced as the result of an unexpected event. Surprise can have any valence; that is, it can be neutral/moderate, pleasant, or unpleasant. If a person experiences a very powerful or long lasting surprise, it may be considered shock.-Reality...
and it is possible for one to induce self-knismesis, by light touching.
Gargalesis, on the other hand, produces an odd phenomenon: when a person touches “ticklish” parts on their own body no tickling sensation is experienced. It is thought that the tickling requires a certain amount of surprise, and because tickling oneself produces no unexpected motion on the skin, the response is not activated. A recent analysis of the “self-tickle” response has been addressed using MRI technology. Blakemore and colleagues have investigated how the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
distinguishes between sensations we create for ourselves and sensations others create for us. When the subjects used a joystick
Joystick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...
to control a "tickling robot", they could not make themselves laugh. This suggested that when a person tries to tickle himself or herself, the cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
sends to the somatosensory cortex precise information on the position of the tickling target and therefore what sensation to expect. Apparently an unknown cortical
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
mechanism then decreases or inhibits the tickling sensation.
Tickling as physical abuse
Although consensual tickling can be a positive, playful experience, non-consensual tickling can be frightening and painful for the recipient. Therefore, non-consensual tickling—as with all non-consensual activities—can be categorized as a form of physical abuse, and sources indicate that tickling has been used as a form of torture. Heinz HegerHeinz Heger
Heinz Heger was the pen name used by Josef Kohout , an Austrian Nazi concentration camp survivor. Kohout had been imprisoned for his homosexuality, which the German penal code's Paragraph 175 made criminal...
, a homosexual man imprisoned in the Flossenburg concentration camp
Flossenbürg concentration camp
Konzentrationslager Flossenbürg was a Nazi concentration camp built in May 1938 by the Schutzstaffel Economic-Administrative Main Office at Flossenbürg, in the Oberpfalz region of Bavaria, Germany, near the border with Czechoslovakia. Until its liberation in April 1945, more than 96,000 prisoners...
during World War II, witnessed Nazi prison guards perform tickle torture on a fellow inmate. He describes this incident in his book The Men With The Pink Triangle: "The first game that the SS sergeant and his men played was to tickle their victim with goose feathers, on the soles of his feet, between his legs, in the armpits, and on other parts of his naked body. At first the prisoner forced himself to keep silent, while his eyes twitched in fear and torment from one SS man to the other. Then he could not restrain himself and finally he broke out in a high-pitched laughter that very soon turned into a cry of pain, while the tears ran down his face, and his body twisted against his chains. After this tickling torture, they let the lad hang there for a little, while a flood of tears ran down his cheeks and he cried and sobbed uncontrollably."
An article in the British Medical Journal
British Medical Journal
BMJ is a partially open-access peer-reviewed medical journal. Originally called the British Medical Journal, the title was officially shortened to BMJ in 1988. The journal is published by the BMJ Group, a wholly owned subsidiary of the British Medical Association...
describes a European method of tickle torture in which a goat was compelled to lick the victim's feet after they had been dipped in salt water. Once the goat had licked the salt off, the victim's feet would be dipped in the salt water again and the process would repeat itself. In ancient Japan, authority figures could administer punishments to those convicted of crimes that were beyond the criminal code. This was called shikei, which translates as ‘private punishment.’ One such torture was kusuguri-zeme: "merciless tickling."
In his book Sibling Abuse, Vernon Wiehe published his research findings regarding 150 adults who were abused by their siblings during childhood. Several reported tickling as a type of physical abuse they experienced, and based on these reports it was revealed that abusive tickling is capable of provoking extreme physiological reactions in the victim, such as vomiting and losing consciousness.
See also
- Knismesis and gargalesisKnismesis and gargalesisKnismesis and gargalesis are the scientific terms, coined in 1897 by psychologists G. Stanley Hall and Arthur Allin, used to describe the two types of tickling.- Knismesis :...
- Tickling fetishismTickling fetishismTickling games are interpersonal or social activities involving the tickling of one person by another. Many people find tickling to be a pleasurable experience in its own right, but also an erotic experience. Some people are sexually excited by being tickled or by tickling another person...
(Knismolagnia) - Tickle tortureTickle tortureTickle torture is the use of tickling to abuse, dominate, humiliate or even "prank" someone. The victim laughs even if he or she finds the experience unpleasant because the laughter is an innate reflex rather than social conditioning...