Editing Tickling (section)

==Physiology==
[[File:James John Hill (circle) Being tickled.jpg|alt=|thumb|James John Hill]]
Tickling results from a mild stimulation moving across the skin, and is associated with behaviors such as smiling, laughter, twitching, withdrawal and [[goose bumps]].

The tickle can be divided into two separate categories of sensation, [[knismesis and gargalesis]]. Knismesis, also known as a "moving itch", is a mildly annoying sensation caused by a light movement on the skin, such as from a crawling insect. This may explain why it has evolved in many animals.<ref name="Selden, S. T. 2004">{{cite journal |last1=Selden |first1=S. T. |year=2004 |title=Tickle |journal=Journal of the American Academy of Dermatology |volume=50 |issue=1|pages=93–97 |doi=10.1016/s0190-9622(03)02737-3 |pmid=14699372}}</ref> For example, a dog exhibiting the [[scratch reflex]] is an example of knismesis. When stimulated in the saddle region, most dogs will exhibit a reflexive rhythmic twitching of their hind legs. This reflex can be brought on by actions such as scratching, brushing, stroking, or even tapping the sensitive area. Horses also exhibit a response to knismesis, as they can be observed twitching the panniculus carnosus muscle in response to insects landing on their sides. Gargalesis reactions refer to a laughter-provoking feeling caused by a harsher, deeper pressure, stroked across the skin in various regions of the body.<ref name="Selden, S. T. 2004" /> These reactions are thought to be limited to humans and other [[primate]]s, although some research has indicated that [[rat]]s can also be tickled in this way.<ref>{{cite journal |vauthors=Panksepp J, Burgdorf J |title="Laughing" rats and the evolutionary antecedents of human joy? |url=http://www.psych.umn.edu/courses/fall06/macdonalda/psy4960/Readings/PankseppRatLaugh_P&B03.pdf |journal=Physiol. Behav. |volume=79 |issue=3 |pages=533–547 |year=2003 |pmid=12954448 |doi=10.1016/S0031-9384(03)00159-8|s2cid=14063615 }}</ref> A German study also indicates that the gargalesis type of tickle triggers a defense mechanism for humans in the [[hypothalamus]] conveying submissiveness or fleeing from danger.<ref>{{Cite web|url=https://bigthink.com/robby-berman/why-we-may-love-to-tickle-but-we-mostly-hate-to-be-tickled-ourselves|title=The Psychology of Tickling And Why It Makes Us Laugh|date=12 July 2016|website=Big Think}}</ref>

It appears that the tickle sensation involves signals from [[nerve fibre]]s associated with both [[pain]] and [[tactition|touch]]. In 1939, [[Yngve Zotterman]] of the [[Karolinska Institute]] studied the knismesis type of tickle in cats, by measuring the [[action potential]]s generated in the [[nerve]] fibres while lightly stroking the skin with a piece of [[cotton]] [[wool]]. Zotterman found that the "tickling" sensation depended, in part, on the nerves that generate pain.<ref>{{cite journal |author=Zotterman Y |year=1939 |title=Touch, pain and tickling: An electrophysiological investigation on cutaneous sensory nerves |journal=Journal of Physiology |volume=95 |issue=1|pages=1–28 |pmc=1393960 |pmid=16995068 |doi=10.1113/jphysiol.1939.sp003707}}</ref> Further studies have discovered that when the [[pain]] nerves are severed by surgeons, in an effort to reduce [[chronic pain|intractable]] pain, the tickle response is also diminished.<ref>{{cite journal |vauthors=Lahuerta J, etal |title=Clinical and instrumental evaluation of sensory function before and after percutaneous anterolateral cordotomy at cervical level in man |journal=Pain |volume=42 |issue=1 |pages=23–30 |year=1990 |pmid=1700355 |doi=10.1016/0304-3959(90)91087-Y |s2cid=24785416 }}</ref> However, in some patients that have lost pain sensation due to [[spinal cord injury]], some aspects of the tickle response do remain.<ref>{{cite journal |author=Nathan PW |title=Touch and surgical division of the anterior quadrant of the spinal cord |journal=J. Neurol. Neurosurg. Psychiatry |volume=53 |issue=11 |pages=935–939 |year=1990 |pmid=2283523 |doi=10.1136/jnnp.53.11.935 |pmc=488271}}</ref> Tickle may also depend on nerve fibres associated with the sense of touch. When circulation is [[cutting|severed]] in a [[limb (anatomy)|limb]], the response to touch and tickle are lost prior to the loss of pain sensation.<ref name="Harris" />

{{anchor|areas}}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 is far more sensitive to touch, most people find that the soles of their feet are the most ticklish.<ref name=Harris /><ref name="hall">{{cite journal |last1=Hall |first1=G. Stanley |last2=Alliń |first2=Arthur |title=The Psychology of Tickling, Laughing, and the Comic |journal=The American Journal of Psychology |date=1897 |volume=9 |issue=1 |pages=1–41 |doi=10.2307/1411471 |url=https://www.jstor.org/stable/1411471 |access-date=28 August 2024 |issn=0002-9556|url-access=subscription }}</ref> Other commonly ticklish areas, in decreasing order of effect, include the [[armpit]]s, the neck, under the chin and the ribs.<ref name="hall"/>

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.<ref>{{cite journal |vauthors=Newman B, O'Grady MA, Ryan CS, Hemmes NS |title=Pavlovian conditioning of the tickle response of human subjects: Temporal and delay conditioning |journal=Perceptual and Motor Skills |volume=77 |issue=3 Pt 1 |pages=779–785 |year=1993 |pmid=8284153 |doi=10.2466/pms.1993.77.3.779|s2cid=38446310 }}</ref>

=== Tickle fight ===
A tickle fight is a playful [[Leisure|leisure activity]]<ref>{{cite web |last= |first= |title=Can You Tickle Yourself? |url=https://wonderopolis.org/index.php/wonder/can-you-tickle-yourself |access-date=}}</ref> in which two people, or sometimes more, tickle each other to the point where one of the participants gives up.{{citation needed|date=January 2024}} It can occur as a sudden outburst without consensus about it,{{citation needed|date=January 2024}} or as a carefully designed challenge with clear ground rules.<ref name="usatoday">{{cite web |last=Randazza |first=Janelle |date=28 February 2021 |title=6 reasons why you should roughhouse with your kids |url=https://reviewed.usatoday.com/parenting/features/why-you-should-roughhouse-with-your-kids |access-date=3 January 2024 |website=usatoday.com |publisher=USA Today}}</ref> Tickle fighting is similar to [[Pillow fight|pillow fighting]], in the sense that they are both silly and playful activities, usually not taken too seriously.{{citation needed|date=January 2024}} Tickle fighting is especially enjoyed by young children.<ref>{{cite web |last1=Grigg |first1=Tessa |last2=Cummings |first2=Bindy |date= |title=Rough and Tumble – Learning Through Play |url=https://www.gymbaroo.com.au/articles/rough-and-tumble-learning-through-play/ |access-date=3 January 2024 |website=gymbaroo.com.au |publisher=GymbaROO KindyROO}}</ref> Tickle fight should not be confused with [[tickle torture]], which is an abusive and serious torturing method.{{citation needed|date=January 2024}}

A participant in a tickle fight can be called a tickler.<ref>{{cite web |last= |first= |title=James 2:12–13 |url=https://www.firstlarne.org.uk/blog/tickle-fights-and-mercy |access-date=}}</ref><ref name="slate">{{cite journal |last1=Palmer |first1=Brian |date=12 March 2010 |title=Why do we tickle? |url=https://slate.com/technology/2010/03/rep-eric-massa-tickled-his-staff-is-that-normal.html |journal=Slate |access-date=}}</ref><ref>{{cite web |last= |first= |title=It's the tickle not the tickler |url=https://www.newscientist.com/article/mg15320712-300-science-its-the-tickle-not-the-tickler/ |access-date=}}</ref>