Tickled: The strange (but true) story of competitive endurance tickling, catfishing, and trolling

Last month, an article that I wrote on knismolagnia (in which individuals derive sexual pleasure and arousal from tickling or being tickled) was featured in an online article in Vox about the documentary Tickled and the world of ‘competitive endurance tickling’ (CET). Given that endurance sports are by definition ‘extreme’ and that I have examined other extreme sports and endurance events in my previous blogs, I thought that CET would make an interesting topic to examine. Tickled was co-directed by the New Zealand journalist David Farrier and the videographer Dylan Reeve but turned out to be a far more interesting film than just about CET. It all started when Farrier came across an online advert placed by Jane O’Brien Media (JOBM):

“This is a shout out to TICKLISH MALE ATHLETIC FITNESS MODELS (aged 18-25) IN THE USA (all 50 states), CANADA, UK, AUSTRALIA, NEW ZEALAND AND JAPAN. What I’m shooting lately is unique. It’s been exploring several situations in which attractive, ticklish, and masculine guys are actually tickled in two different restrained formats, then involved in demonstrating some tickling skills themselves. Presently, I’ve been shooting all-male casts.  It is important for you to understand from the get-go that this is not a fetish, or adult-oriented content endeavour. Also, no nudity or implied nudity work is a part of anything that I ever shoot. I repeat:  recent shoots have featured all-male casts. This is a completely athletic activity with major competitive and endurance elements involved, including strategy and teamwork. I’m focused on Competitive Reality Endurance Tickling”.

It was when Farrier saw the phrase “Competitive Reality Endurance Tickling” that his journalistic instincts started to stir. The website advert said that successful applicants would be put up in a Los Angeles (US) hotel, have to wear Adidas branded clothes, and be paid US$1500 to participate. One of the CET participants Jordan Schillachi said in an online video: “This is a very competitive company…There’s probably 600 guys every 30 minutes sending pictures to want to get in”. By way of further background, the Wikipedia entry on Farrier noted that:

“In early 2014 Farrier began production of the feature-length documentary ‘Tickled’, which he co-directed with videographer Dylan Reeve. The project began when Farrier sought to do a ‘light entertainment’ piece about videos purported to depict ‘Competitive Endurance Tickling’. His inquiry to Jane O’Brien Media, the videos’ producer, was met with a hostile refusal to talk with him, prompting Farrier and Reeves to investigate further, and the film relates their efforts to find out more about the people involved in making the videos, and the person or persons behind them”.

If you type the words ‘competitive endurance tickling’ into Google, all the links that come up in the first two pages all concern the film Tickled and the various news reports and/or film reviews about it. The JOBM videos featuring CET all feature “young athletic men” who restrain and tickle each other and “compete to see who can stand to be tickled the longest”. Farrier simply wanted to find out more about the so-called ‘sport’ and contacted JOBM about the ‘sport’ and the videos it produced. Farrier received a “hostile” and homophobic response from JOBM that focused on Farrier’s bisexuality and asserting that CET is a “passionately and exclusively heterosexual athletic endurance activity”. The hostility Farrier received and the legal threats he received from JOBM spurred Farrier into making the film. Arguably using bullying tactics, JOBM tried their best to stop the documentary being made. Farrier and Reeve subsequently located where JOBM operated from in Los Angeles, and turn up unannounced at their premises but are turned away at the door of the JOBM offices. The Wikipedia entry on the film noted:

“Their research uncovers information about a person known as Terri DiSisto (or ‘Terri Tickle’), a pioneer of recruiting and distributing tickling videos online, in the 1990s. They interview another tickling-video producer, whose operations are a low-key affair. They speak to a few former participants in O’Brien’s videos, who describe coercive and manipulative treatment by the producers, such as defamation campaigns against them, exposing their personal information and contacting school or work associates to discredit them, in retaliation for challenging or speaking out against the company. A local recruiter in Muskegon, Michigan describes ‘audition’ videos he’d helped make, being published without the participants’ consent. Farrier and Reeve chance upon documents which link O’Brien to David D’Amato, the former school administrator behind the ‘Terri Tickle’ alias, who served a six-month prison sentence for disabling computer systems at two different universities on multiple dates. They determine that D’Amato now lives on a substantial inheritance from his father, a successful lawyer. After considerable effort to locate him, they confront him on the street, to which he responds with additional legal threats. Before returning to New Zealand, Farrier contacts D’Amato’s step-mother for comment; she implicitly confirms his “tickling” past, and he informs her of D’Amato’s ongoing involvement in it”.

The film exposes a ‘tickling ring’ that appears to have been operation for a couple of decades. The Vox article reports that the film tells three simultaneous stories:

“The first and most basic [story] is about people who like tickling and being tickled. The second, deeper story is about catfishing – the kind of systematic, continual deception you sometimes encounter when manipulative individuals obscure their identities online. The catfisher at the center of ‘Tickled’ may be shrouded in mystery, at least until the film really gets going, but they aren’t the stereotypical lonely human on the internet. Whoever’s responsible orchestrates an elaborate plot involving lawyers, a battery of legal threats and actual lawsuits, a cadre of real minions who willingly helped carry out the ruse, and a host of nubile young men who get paid to be tickled. And that leads to [the film’s] third and most compelling story, which is a story about power. ‘Tickled’ is what happens when you put power, wealth, and privilege into the hands of an internet troll with a single-minded goal: to crush his enemies and film people being tickled. ‘Tickled’ is a procedural; the process of how Farrier and Reeve uncover their story takes up most of the documentary’s narrative…‘Tickled’ occasionally gets into the nitty-gritty details of confirming the catfisher’s ultimate identity – by investigating website domains, stock photos, and more – in a way that might bore some viewers. But the clues Farrier and Reeve unearth along the way are generally so weird and unique that many people will find it riveting”.

The Vox article went on to question whether CET is just a creative name for a sexual fetish (which is where my previous article on knismolagnia made an appearance). Farrier’s view was that the videos might perhaps be about JOBM producing homoerotic fetish videos that they could make money from. (JOBM strenuously denied they sold the videos for such purposes. “This is not a fetish, or adult-oriented content endeavor”). The Vox article also said:

“Tickled explores the nature of tickling fetishes and the personalities of the people who wind up monetizing them: The documentary features one film producer who quit his day job after realizing he could make thousands of dollars a month by catering to people with this very specific fetish”.

When Farrier began writing about CET in 2014, online readers responded by saying that his writings reminded them of stories about an internet troll that had been operating with a similar modus operandi a couple of decades previously. Farrier cam to the conclusion that the troll and JOBM might in fact be one and the same. As Farrier observed:

“If you Googled ‘tickling videos’ and ‘internet,’ the story came up, so we made that connection very, very quickly. The circumstantial coincidence of how they [both] operated was very obvious, but going deeper than that was harder for us. To actually prove any of it – that’s the journey of this documentary. It’s good to go in cold and just let it unfold in front of you, and then, at the end of it, you should spend a little time thinking it all through again and decide how you feel. That’s what we did experiencing the whole thing, and I think that’s good for you as an audience as well”.

So if you want to know whether Farrier’s suspicions were confirmed, you’ll have to go and watch the film – but I’ll just end by noting that JOBM have now produced their own website (‘Tickled, The Truth’) to counter Farrier’s claims.

Dr Mark Griffiths, Professor of Behavioural Addiction, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Aggrawal A. (2009). Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices. Boca Raton: CRC Press.

Blackwell, S. (2016). Tickling. Prodomme. Located at: http://www.prodomme.com/fetishes/tickling

Farrier, D. (2014). Homophobia and competitive tickling. 3 News, May 7. Located at: https://web.archive.org/web/20140603201419/http://www.3news.co.nz/Homophobia-and-competitive-tickling/tabid/418/articleID/343206/Default.aspx

Him and Her Sex Blog (2012). Knismolagnia. February 12. Located at: http://himandhersexblog.tumblr.com/post/17661996177/knismolagnia

Right Diagnosis (2012). Knismolagnia. Located at: http://www.rightdiagnosis.com/k/knismolagnia/intro.htm

Romano, A. (2016). New documentary ‘Tickled’ takes you into a world of sexual fetishes, catfishing, and internet secrets unearthed. Vox, June 21. Located at: http://www.vox.com/2016/6/21/11963566/tickled-competitive-tickling-documentary-explained

Wikipedia (2012). Catfishing. Located at: https://en.wikipedia.org/wiki/Catfishing

Wikipedia (2012). Tickled. Located at: https://en.wikipedia.org/wiki/Tickled

Wikipedia (2012). Tickling game. Located at: http://en.wikipedia.org/wiki/Tickling_game

From the university of perversity: An A to Z of non-researched sexual paraphilias

One of my students asked me the other day whether I will ever run out of sexual paraphilias to write about. I may run out of paraphilias that have been scientifically researched but the one thing I’ve learned from all my reseach into human sexual behaviour is that human beings appear to have the capacity to become sexually aroused to almost anything. Today’s blog takes a brief A to Z look at 26 paraphilias where (as far as I am aware) there is absolutely no empirical or clinical research on the topic. In fact, in almost all of the paraphilias listed here, I couldn’t even find an anecdotal case study or an online forum where people discuss such issues. The majority of the paraphilias below can be found in either Dr. Anil Aggrawal’s book Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices and/or Dr. Brenda Love’s Encyclopedia of Unusual Sex Practices. Just to make things a little more interesting, one of the 26 paraphilias listed below is one that I made up.

• Anasteemaphilia: This is where individuals derive sexual arousal to individuals who are much taller or shorter than themselves (i.e., it is the large difference in height that is the primary source of sexual arousal)
• Batrachophilia: This is a sub-type of zoophilia where individuals derive sexual arousal from and/or attraction to frogs. The Victorious Vocabulary website says that it relates to an extreme fondness for frogs, or a sexual obsession with frogs.
• Cratophilia: This is where individuals derive sexual arousal from displays of strength. I have only come across one academic paper that makes a specific reference to ‘cratophilia’ and that was a study led by Dr G. Scorolli on the relative prevalence of different fetishes using online fetish forum data. They reported that some of the sites featured references to ‘muscle fetishes’ (5% of all sites concerned with bodily features) and that some of these related to cratophilia (although it also featured individuals who were sthenophiles who prefer the look of the muscles rather than acts of bodily strength)
• Doraphilia: This is where individuals derive sexual arousal from animal fur, leather, and/or skin. The Wikipedia page on clothing and garment fetishes mentions doraphilia in passing but there is no supporting empirical evidence.
• Endytophilia: This is where individuals derive sexual arousal only from partners who are clothed during sexual intercourse. The only interesting things I found on the internet relating to endytophilia was that (a) it contained the letters for the word ‘depiliation’, and (b) it was claimed in an online article by Tony Leather that the most famous endytophile was Elvis Presley.
• Fratrilagnia: This is where individuals derive sexual arousal from having sex with one’s own brother. Although I am aware cases of brother-sister incest, the implication from the behaviour being classified as a sexual paraphilia is that it is the fact being a brother is the primary source of the individual’s sexual behaviour.
• Geusophilia: This is where individuals derive sexual arousal through taste (presumably of food but none of the definitions I’ve come across make that explicit – seem my previous blog on sitophilia).
• Hyphephilia: This is where individuals derive sexual arousal from touching skin, hair, leather, fur or fabric. This appears to be very similar to doraphilia (above) but includes a greater number of tactile materials from which an individual derives sexual pleasure.
• ldrophrodisia: This is where individuals derive sexual arousal from the odour of perspiration, especially from the genitals. This would appear to be a sub-type of olfactophilia (sexual arousal from smells and odour).
• Juvenilophilia: This is where individuals derive sexual arousal from having sex with juveniles.
• Knismolagnia: This is where individuals derive sexual arousal from tickling. Since writing this article I managed to collect enough anecdotal material to write a whole blog on this paraphilia.
• Lyssophilia: This is where individuals derive sexual arousal from becoming angry or upset.
• Moriaphilia: This is where individuals derive sexual arousal from telling sexual jokes. This may be related to other psychological conditions such as ‘punning mania’ although this sexual paraphilia (if it really exists) could be argued to be a sub-type of narratophilia.
• Nosolagnia: This is where individuals derive sexual arousal from knowing partner has terminal illness. Although I have never come across a case of nosolagnia, I would imagine it has psychological overlaps with those individuals who seek sexual arousal from vulnerable individuals (such as those who sexually exploit the learning disabled).
• Ochlophilia: This is where individuals derive sexual arousal from being in a crowd. This would appear to have some overlap with frotteurism (sexual arousal from rubbing up against people and which I examined in a previous blog).
• Placophilia: This is where individuals derive sexual arousal from tombstones. After finding out what placophobia was, the musician and author Julian Cope claimed he must be a placophile on a post at his Head Heritage website (although my guess is that his love for tombstones is not sexual).
• Quadoshka: OK, I admit this a little bit of a cheat as there are so few sexual paraphilias beginning with the letter ‘Q’ (and I’ve already covered queefing in a previous blog). Quadoshka is where individuals derive sexual arousal American Indian form of tantric sex.
• Rhytiphilia: This is where individuals derive sexual arousal from facial wrinkles. This would appear to be related to gerontophilia (sexual arousal to people who are much older than the individuals themselves).
• Septophilia: This is where individuals derive sexual arousal to decaying matter (presumably human or something else that was once living, but none of the definitions I have come across make any specific references). This paraphilia would therefore appear to have clear overlaps with necrophilia (sexual arousal from dead people) and necrobestiality (sexual arousal from dead animals).
• Timophilia: This is where individuals derive sexual arousal comes from gold or wealth. Given that money and/or wealth are often said to be aphrodisiacs, I would have thought there would be lots of research into this, but I have yet to come across any. However, it is one of the few paraphilias that is listed here that appears on the Right Diagnosis online medical website. This also reminds me of the interview on the Mrs. Merton Show where Debbie McGee was asked “So, what first attracted you to the millionaire Paul Daniels?”
• Uranophilia: This is where individuals derive sexual arousal from heavenly thoughts. One online definition claims that uranophilia is the “ultimate expression of faith in that you can take such joy, such pleasure from the mere thought of heaven alone”. I am very doubtful that this paraphilia even exists.
• Vicarphilia: This is where individuals derive sexual arousal from other people’s sexual experiences. To me, this sounds remarkably like a form of narratophilia (that I covered in a previous blog). One online dictionary goes much further in its definition and defines vicarphilia as “vicarious arousal sexual arousal from other peoples’ exciting actions, experiences and behaviors and sexual attraction for people who lead exciting lives, such as influential people, celebrities, gangsters, and people who engage in dangerous sports such as racers, daredevils, and action sportsters”.
• Wing Fetishism: This is where individuals derive sexual arousal from wings – but not from bird or animal wings but from angel or demon wings. I know of no literature on this at all but I am assuming it is a fantasy-based paraphilia like macrophilia (sexual arousal for giants).
• Xylophilia: This is where individuals derive sexual arousal from wooden objects. This may have some overlap with the next sexual paraphilia on this list (i.e., ylophilia).
• Ylophilia: This is where individuals derive sexual arousal from forests. The Fetish News website defines ylophilia as an extreme affinity for forests, including sexual attraction to or arousal from the texture and shape of trees and shrubs. This would therefore seem to overlap with dendrophilia (sexual arousal from trees, that I covered in a previous blog).
• Zelophilia: This is where individuals derive sexual arousal from jealousy.

So did you spot the one I made up? If you think you know which one it is or want to know, email me directly at: mark.griffiths@ntu.ac.uk. Also, if you have any information on any of the paraphilias listed here I would love to hear from you.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Aggrawal A. (2009). Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices. Boca Raton: CRC Press.

Caust, D. (undated). Sex sense: Unusual sexual behavior. Located at: http://www.drdeborahcaust.com/articles/pdf/ss9_unusual.pdf

Gates, K. (2000). Deviant Desires: Incredibly Strange Sex. New York: RE/Search Publications.

Leather, T. (2012). What floats your sexual boat? Wikinut, September 9. Located at: http://news.wikinut.com/What-Floats-Your-Sexual-Boat/3vg12rx5/

Love, B. (2001). Encyclopedia of Unusual Sex Practices. London: Greenwich Editions.

Scorolli, C., Ghirlanda, S., Enquist, M., Zattoni, S. & Jannini, E.A. (2007). Relative prevalence of different fetishes. International Journal of Impotence Research, 19, 432-437.

Wikipedia (2013). Clothing fetish. Located at: http://en.wikipedia.org/wiki/Clothing_fetish

Tickled pink: A brief look at knismolagnia

“My friend’s sister always asked me to tickle her, and I would. Then one day I was tickling her and she climaxed and kissed me. It freaked me out because I wasn’t tickling near her private parts. I thought that maybe it was a one time thing, so I tickled her two more times on different occasions, and she climaxed both times” (posting on the ‘Is It Normal?’ website)

There are hundreds of sexual paraphilias of which little is known. One of the most obscure paraphilias but which is definitely known to exist is knismolagnia. According to Dr. Anil Aggrawal in his 2009 book Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices, knismophilia is a sexual paraphilia in which individuals derive sexual pleasure and arousal from tickling or being tickled (and is also known as titillagnia). The Right Diagnosis website claims the symptoms of knismolagnia are (i) sexual arousal gained from being tickled, (ii) sexual interest in tickling, (iii) recurring intense sexual urges involving tickling, and (iv) sexual arousal associated with tickling. A knismolagnia article on another online site (Gay Fetish Goth) claims that different individuals may find tickling of virtually any region of the body to be pleasurable, and that knismolagnia can also involve sexual arousal from simply watching others being tickled. The same article also noted (but without any supporting evidence) that:

“However, people who claim to have a tickling fetish are likely to enjoy this activity to the exclusion of other pre-sex activities. For some, the focus is entirely on the tickling, with full intercourse less important or not included at all. People whose sexuality is based almost solely on tickling can be said to have a tickling fixation. This fixation may also exist outside of sexual contexts”.

As far as I can ascertain, there is almost nothing in the academic literature on knismolagnia. However, there are a number of online articles and writings about the sexual side of tickling although there is a common mistake I have spotted which may both have arisen from a single source. Many online sources – including the Acarophilia and Kinky Sex Questions websites – appear to include tickling as part acarophilia (the deriving of sexual arousal and pleasure from scratching or being scratched) when in fact it is not (although there is clearly a fine line between hard tickling and scratching).

In 2006, Dr. Lisa Shaffer and Dr. Julie Penn developed a comprehensive paraphilia classification system and published it as a book chapter in Dr. William Hickey’s book Sex Crimes and Paraphilia. In this chapter, Shaffer and Penn made specific reference to both acarophilia and knismolagnia although these mentions (while in an academic context) were part of a wider theoretical point noting that some paraphilias (specifically acarophilia and knismolagnia – although they used the term ‘titillagnia’ for the latter) were completely “innocuous” and that this demonstrated that not all sexual paraphiliacs were sex offenders (and vice-versa). This appears to be supported by the Right Diagnosis website which claims that treatment for knismolagnia is generally not sought and that individuals with the condition “simply learn to accept their fetish and manage to achieve gratification in an appropriate manner”.

According to a small article on the Kinky Sex Questions website (which also wrongly interchanges acarophilia and knismolagnia), sexual tickling is most “frequently done by fingers, feather and other objects or by licking”. It claims that initially, the person being tickled enjoys and encourages the tickler, but then turns into “helpless laughter”. The article also claims that the preferred tickling areas are “feet, armpits, navel, ribs, breasts and genitals” (although no evidence is given to support the claim). If this is true there is likely to be some crossover with other sexual paraphilias and fetishes including podophilia (i.e., foot fetishes) and maschalagnia (i.e., armpit fetishism).

The Acarophile website also contains an “Acarophilia Dictionary” which appears to relate acarophilia to a more specialized and idiosyncratic sub-type of sexual sadism and sexual masochism (in fact there appear to dozens of websites that cater for ‘tickle torture’ pornography if you do a quick Google search). The website uses the word ‘ticklephile’ to define “anyone, including adults and children of both sexes who have an acute interest, or fetish, about tickling or being tickled”. It also features some more specialized definitions including the ‘Tickle Top’, the ‘Tickle Bottom’, ‘Tickle Torture’ and a ‘Douhini’. These are the verbatim definitions from the Acarophilia Dictionary rather than my own re-wording:

• Tickle Top: 
This refers to “the person who tickles, or tickle tortures another with the object of forcing the victim, usually restrained and helpless, to laugh hysterically, cry, scream, urinate, ejaculate and even pass out from prolonged intense tickling. Usually done with consent for erotic sexual gratification, but sometimes used as effective torture of prisoners”.
• Tickle Bottom: 
This refers to “the victim, usually restrained, of tickle torture, either with consent by a tickle top for exercise or sexual gratification or by others as torture to obtain information or for sadistic pleasure. If very ticklish, the ‘bottom’ suffers acute agony from the body’s automatic reflexes, such as hysterical laughter, screaming, crying, muscle spasms, urination, ejaculation, and even convulsions and loss of consciousness. Common in BDSM, (bondage sado-masochism) practice, the tickle bottom should be in good physical health because severe tickling can cause strokes and seizures”.

• Tickle Torture: 
This refers to a tied-up victim “be it in a rack or with ropes or hand-cuffs, in a strategic method, and tickled mercilessly. Usually, words are written on the victim’s feet, and pictures are taken, both still and moving. Rarely does sex occur, although erections and urination may”.

• Douhini: 
This refers to a “tickle of the inside of an exposed armpit. The Douhini-er must then yell Douhini to further surprise the victim. Usually accompanied by a slight wave of the pointer finger. In other cases a Douhini can also be a jab to the armpit but that technique is usually frowned upon”.

According to most online sources, the main reason why sexual tickling is popular among those in the BDSM community is because the person is usually already restrained. The dominant partner may also blindfold their victim to enhance the sexual pain/pleasure. However, one online gay fetish site claims it is not popular. It asserted that “although some consider [knismolagnia] a BDSM activity, tickling is not fully recognised by the community and is relatively unknown in the mainstream. In dominance and submission scenarios, sexual partners may agree upon a safeword to signal that the tickling should stop”. According to a Wikipedia entry on tickling games, knismolagnia is derived from the term ‘knismesis’:

“Knismesis refers to the light, feather-like type of tickling. This type of tickling generally does not induce laughter and is often accompanied by an itching sensation. The knismesis phenomenon requires low levels of stimulation to sensitive parts of the body, and can be triggered by a light touch or by a light electrical current. Knismesis can also be triggered by crawling insects or parasites, prompting scratching or rubbing at the ticklish spot, thereby removing the pest”

Knismolagnia also includes ‘gargalesis’ which according to an article on knismolagnia in the (admittedly non-academic) ‘Him and Her Sex Blog’ refers to:

“…harder, laughter-inducing tickling, and involves the repeated application of high pressure to sensitive areas. This ‘heavy tickle’ is often associated with play and laughter. The gargalesis type of tickle works on humans and primates, and possibly on other species. Because the nerves involved in transmitting ‘light’ touch and itch differ from those nerves that transmit ‘heavy’ touch, pressure and vibration, it is possible that the difference in sensations produced by the two types of tickle are due to the relative proportion of itch sensation versus touch sensation. While it is possible to trigger a knismesis response in oneself, it is usually impossible to produce gargalesthesia, the gargalesis tickle response, in oneself”

This short article also claims that varying forms and varying degrees of knismolagnia “from the pleasure experienced when tickled by a partner, to the sexual need to be tickled to reach orgasm”. It is also one of the few articles to note that knismolagnia doesn’t include non-tickling behaviours such as scratching and cutting. Of all the paraphilias I have examined in my blog, knismophilia appears to have been one of the least researched (academically or clinically).

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Aggrawal A. (2009). Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices. Boca Raton: CRC Press.

Hickey, E. (2006). Sex Crimes and Paraphilia. Prentice Hall, New Jersey: Pearson.

Him and Her Sex Blog (2012). Knismolagnia. February 12. Located at: http://himandhersexblog.tumblr.com/post/17661996177/knismolagnia

Right Diagnosis (2012). Knismolagnia. Located at: http://www.rightdiagnosis.com/k/knismolagnia/intro.htm

Shaffer, L. & Penn J. (2006). A comprehensive paraphilia classification system. In E.W. Hickey (Ed.), Sex Crimes and Paraphilia (pp. 69-93). Prentice Hall, New Jersey: Pearson.

Wikipedia (2012). Tickling game. Located at: http://en.wikipedia.org/wiki/Tickling_game