The Kiss

The Kiss 1907–08, oil on canvas

Sometimes it’s down to art. My inspiration, that is. In this case it was Gustav Klimt's 'The Kiss'. I recently watched a documentary on Klimt, and shortly thereafter happened upon an article about the mouth bacteria we spread through kissing. Seeing as I am aiming to keep this blog rooted in science, however, the information I have collected will be focused on the latter. That said, I have included a reproduction of 'The Kiss' front and centre – so I can enjoy it while I write; and perhaps, you may enjoy it while you read. (Though if Klimt's not your cup of tea, how about a Caravaggio?)

"The Taking of Christ" by Caravaggio depicts Judas
 betraying Jesus with a kiss as a signal to arrest Jesus.

The Kiss, be it an act of betrayal, ritual, superstition, affection, nurturing, lust or friendship; the act itself has endured in one form or another for millennia.  

According to a Dutch study[1]  conducted by Professor Remco Kort, in which 21 couples were asked to tongue-kiss for 10 seconds, it was found that:

• The oral flora on the tongue of the partners seem to be much more alike than the oral flora of random persons. … Remco Kort:

"It didn’t matter whether the partners said they tongue-kissed 9 times a day or 9 times a year. Obviously there are other key factors at work, such as having the same diet or using the same toothpaste." 

• In the saliva, however, there was a clearly discernible effect: the more often you tongue-kiss each other, the more alike the collection of bacteria in your saliva becomes.

• On average you exchange around 80 million bacteria during a 10-second tongue kiss. 

Cultural Practices & Perceptions

Kissing has been recorded for at least the last five millennia. The earliest literate civilization in the world, Sumer, mentions both lip and tongue kissing in its poetry.[2][3] 

The study of kissing started some time in the nineteenth century and is called Philematology.[2][4][5] 

Kissing was introduced to certain cultures only through European settlement, before which, it was not a routine occurrence. Such cultures included certain indigenous peoples of Australia, the Tahitians, and many tribes in Africa.[2][6] 

Instead of kissing, Manchu* mothers used to show affection for their children by performing fellatio on their male babies. Unlike kissing in public, which was regarded with revulsion, this act was not considered sexual.[2][7][8][9][10][11] 

*The Manchu are a Chinese ethnic minority and the people from whom Manchuria derives its name.[12][13]  

In 2007, two people were fined and jailed for a month after kissing and hugging in public in Dubai.[2][14] 

In 2008, Singapore's Media Development Authority fined cable firm StarHub after it broadcast an advertisement showing two women kissing.[2][15] 

Origins & Physiology etc.

Black-tailed prairie dogs "kissing." Prairie dogs use a
nuzzle of this variety to greet their relatives.[2][16] 

Anthropologists have not reached a consensus as to whether kissing is a learned or instinctive behaviour. It may be related to grooming behaviors seen between other animals, or have evolved from the direct mouth-to-mouth regurgitation of food (kiss-feeding or premastication) from parent to offspring – a behaviour observed across various species and cultures.[2][17]

Male to female (courtship feeding) has also been observed in numerous mammals.[2][17][18]

Non-human primates also exhibit kissing behavior.[2][19] 

Dogs, cats, birds and other animals display licking, nuzzling, and grooming behavior among themselves, and also towards humans and other species.[2]

Kissing is a complex behavior that requires significant muscular coordination involving a total of 34 facial muscles and 112 postural muscles.[2][19][20] The most important muscle involved is the orbicularis oris muscle, which is used to pucker the lips and is informally known as the kissing muscle.[2][21][22]

Lips have many nerve endings which make them sensitive to touch and bite.[2][23]

Affection in general has stress-reducing effects. In a study published in the Western Journal of Communication, entitled, Kissing in Marital and Cohabiting Relationships: Effects on Blood Lipids, Stress, and Relationships, it was found that increasing the frequency of kissing in marital and cohabiting relationships results in a reduction of perceived stress, an increase in relationship satisfaction, and a lowering of cholesterol levels.[2][24] 

Below is an excerpt from an article[25] published on the website WebMD.com, entitled, What’s so Great About Kissing?

"Kissing might even help you lose weight", says Bryant Stamford, PhD, professor and director of the health promotion center at the University of Louisville. "During a really, really passionate kiss, you might burn two calories a minute -- double your metabolic rate," he says. (This compares to 11.2 calories per minute you burn jogging on a treadmill.)” 

Viruses

Kissing on the lips can result in the transmission of some diseases, including infectious mononucleosis* and herpes simplex* when the infectious viruses are present in saliva.[2]

Research indicates that contraction of HIV* via kissing is extremely unlikely, although there was a documented case in 1997 of an HIV infection by kissing. However, both the woman and infected man had gum disease, so transmission was through the man's blood, not through saliva.[2][26]

*Infectious mononucleosis is an infectious, widespread viral disease caused by the Epstein–Barr virus (EBV), one type of herpes virus, against which over 90% of adults are likely to have acquired immunity by the age of 40.[27][28][29]

Swollen lymph nodes in the neck in someone
with infectious mononucleosis

*Herpes simplex is a viral disease from the herpesviridae family caused by both Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2).[30]  Oral herpes, the visible symptoms of which are commonly called 'cold sores' or 'fever blisters', is an infection of the face or mouth. Oral herpes is the most common form of infection.[30]

Herpes labialis of the lower lip

*The human immunodeficiency virus (HIV) causes the acquired immunodeficiency syndrome (AIDS),[31][32][33] a condition in humans, in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive.[31]





Related Links:

Why Do People Kiss? LIVESCIENCE, February 2, 2013







References:

[1] https://www.tno.nl/content.cfm?context=overtno&content=nieuwsbericht&laag1=37&laag2=69&item_id=2014-11-13%2016:03:32.0&Taal=2

[2] http://en.wikipedia.org/wiki/Kiss#cite_note-25 

[3] Kramer, Samuel Noah (1981). History Begins at Sumer (3rd revised. ed.). Philadelphia: University of Pennsylvania Press. pp. 72ff. ISBN 978-0812212761.
[4] "The science of kissing", CNN, Feb. 14, 2012
[5] "Chemical attraction: The science of kissing", Medill Reports, Feb. 14, 2009
[6] Dyer, Tristeleton T.F. "The History of Kissing", The American Magazine, vol. 14 1882, pp. 611–614
[7] Crawley, Ernest. Studies of Savages and Sex, Kessinger Publishing (revised and reprinted) (2006)
[8] Clarke, John R. (2001). Looking at Lovemaking (1st paperback print ed.). Berkeley: University of California Press. pp. 15–16. ISBN 978-0-520-22904-4. "In the Manchu tribe, a mother will routinely suck her small son's penis in public but would never kiss his cheeks. Among adults, the Manchu believe, fellatio is a sexual act, but kissing—even between mother and infant son—is always a sexual act, and thus fellation becomes the proper display of motherly affection."
[9] Barre, Weston La (1975). "The Cultural Basis of Emotions and Gestures". In Davis, Martha. Anthropological Perspectives of Movement. Arno Press. p. 56. ISBN 978-0-405-06201-8. "Manchu kissing is purely a private sexual act, and though husband and wife or lovers might kiss each other, they would do it stealthily since it is shameful to do ... yet Manchu mothers have the pattern of putting the penis of the baby boy into their mouths, a practice which probably shocks Westerners even more than kissing in public shocks the Manchu."
[10] Barre, Weston La (1974). "The Cultural Basis of Emotions and Gestures". In Starr, Jerold M.. Social structure and social personality. Boston: Little, Brown and Company. p. 79.
[11] Halperin, David M.; Winkler, John J.; Zeitlin, Froma I. (1990). Before Sexuality. Princeton: Princeton University Press. p. 3. ISBN 978-0-691-00221-7.
[12] Walls, Neal (2001). Desire, Discord and Death. Boston: American Schools of Oriental Research. p. 81. ISBN 978-0-89757-056-5.
[13] http://en.wikipedia.org/wiki/Manchu_people#cite_note-11
[14] McGreevey, Ronan (March 17, 2007). "Don't kiss the girlfriend in Dubai, don't flush a Swiss loo after 10pm and, whatever you do, don't insult the Thai king". Irish Independent.
[15] "Singapore fines cable firm for ad with lesbian kiss". Reuters. April 9, 2008. 
[16] "How animals kiss and make up". BBC News. October 13, 2003. 

[17] Eibl-Eibesfeldt, Irenäus (1983). "Chapter 3: A comparative approach to human ethology". In Rajecki, D. W. Comparing behavior: studying man studying animals. Routledge
[18] Eibl-Eibesfeldt, Irenäus (1971). "Love and hate: the natural history of behavior patterns". Aldine Transaction
[19] Adrienne Blue (1 June 1996). "The kiss". The Independent (London). Retrieved 29 August 2008.
[20] Roger Highfield (17 October 2006). "Seal with..146 muscles". The Telegraph (London). Retrieved 29 August 2008.
[21] "orbicularis oris muscle". TheFreeDictionary: Mosby's Dental Dictionary, 2nd edition. 2008. Retrieved 3 October 2010.
[22] "Muscles – Facial". BBC: Science & Nature: Human Body & Mind. Retrieved 3 October 2010.
[23] http://www.webmd.com/sex-relationships/features/kissing-benefits

[24] Conis, Elena (4 February 2008). "The mystery of the kiss". Los Angeles Times. Retrieved 7 May 2010.

[25] Kory Floyd, Justin P. Boren, Annegret F. Hannawa, Colin Hesse, Breanna McEwan, Alice E. Veksler (2 April 2009). "Kissing in Marital and Cohabiting Relationships: Effects on Blood Lipids, Stress, and Relationship Satisfaction". Western Journal of Communication(Informaworld.com) 73 (2): 113–133. doi:10.1080/10570310902856071. Retrieved 28 March 2010
[26] Altman, Lawrence K. (11 July 1997). "Case of H.I.V. Transmission Is First to Be Linked to Kiss". New York Times. Retrieved 28 March 2010.
[27] http://en.wikipedia.org/wiki/Infectious_mononucleosis 
[28] "Epstein-Barr Virus and Infectious Mononucleosis". CDC A–Z Index. National Center for Infectious Diseases. 16 May 2006. Retrieved December 6, 2009.
[29] "Glandular fever". NICE Clinical Knowledge Summaries. cks.nice.org.uk. 2010. Retrieved 15 June 2013.
[30] http://en.wikipedia.org/wiki/Herpes_simplex
[31] http://en.wikipedia.org/wiki/HIV
[32] Weiss RA (May 1993). "How does HIV cause AIDS?". Science 260 (5112): 1273–9.Bibcode:1993Sci...260.1273W. doi:10.1126/science.8493571. PMID 8493571.
[33] Douek DC, Roederer M, Koup RA (2009). "Emerging Concepts in the Immunopathogenesis of AIDS". Annu. Rev. Med. 60: 471–84.doi:10.1146/annurev.med.60.041807.123549. PMC 2716400. PMID 18947296. 

Image Credits:


"Gustav Klimt 016" by Gustav Klimt - http://www.belvedere.at/en/sammlungen/belvedere/jugendstil-und-wiener-secession/gustav-klimt. Licensed under Public domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Gustav_Klimt_016.jpg#mediaviewer/File:Gustav_Klimt_016.jpg

"Caravaggio - Taking of Christ - Dublin" by Caravaggio - Web Gallery of Art:   Image  Info about artwork. Licensed under Public domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Caravaggio_-_Taking_of_Christ_-_Dublin.jpg#mediaviewer/File:Caravaggio_-_Taking_of_Christ_-_Dublin.jpg

"Kissing Prairie dog edit 3" by Brocken Inaglory (Photograph edited by Vassil) - Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Kissing_Prairie_dog_edit_3.jpg#mediaviewer/File:Kissing_Prairie_dog_edit_3.jpg

"Lymphadanopathy" by James Heilman, MD - Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Lymphadanopathy.JPG#mediaviewer/File:Lymphadanopathy.JPG

"Herpes(PHIL 1573 lores)" by Original uploader was Bernard bill5 at nl.wikipedia - Transferred from nl.wikipedia. Licensed under Public domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Herpes(PHIL_1573_lores).jpg#mediaviewer/File:Herpes(PHIL_1573_lores).jpg