Editing Smile

{{Short description|Conscious or unconscious facial muscular movement conveying happiness or pleasure}}
{{About|the facial expression|other uses|Smile (disambiguation)|and|Smiles (disambiguation)|and|Smilin'}}{{distinguish|Simile}}
[[File:Leonardo da Vinci 043-mod.jpg|thumb|Detail of the [[Mona Lisa]], who is known for her smile.]][[File:Little_kid_smiling..jpg|thumb|A smiling child.]]
A '''smile''' is a [[facial expression]] formed primarily by flexing the [[muscle]]s at the sides of the [[mouth]]. Some smiles include a contraction of the muscles at the corner of the [[eye|eyes]], an action known as a Duchenne smile. 
Among [[human]]s, a smile expresses [[wikt:delight|delight]], [[socializing|sociability]], [[happiness]], [[joy]], or [[amusement]]. It is distinct from a similar but usually involuntary expression of [[anxiety]] known as a [[wikt:grimace|grimace]]. Although cross-cultural studies have shown that smiling is a means of communication throughout the world,<ref>{{cite book |first=Carroll E. |last=Izard |year=1971 |title=The Face of Emotion |location=New York |publisher=Appleton-Century-Croft |isbn=978-0-390-47831-3 }}frown</ref> there are large differences among different cultures, religions, and societies, with some using smiles to convey confusion, embarrassment, or awkwardness.

== Evolutionary background ==
Primatologist Signe Preuschoft traces the smile back over 30 million years of evolution to a "fear grin" stemming from monkeys and apes, who often used barely clenched teeth to portray to predators that they were harmless<ref>{{Cite journal |url=https://academic.oup.com/scan/article/1/3/221/2362993 |access-date=2022-05-07 |journal=Social Cognitive and Affective Neuroscience | year=2006 |doi=10.1093/scan/nsl031 |pmc=2555422 |pmid=18985109| last1=Parr | first1=L. A. | last2=Waller | first2=B. M. | title=Understanding chimpanzee facial expression: Insights into the evolution of communication | volume=1 | issue=3 | pages=221–228 }}</ref> or to signal submission to more dominant group members. The smile may have evolved differently among species, especially among humans.<ref>{{cite web|url=https://gizmodo.com/why-do-we-smile-and-laugh-when-were-terrified-1441046376|title=Why do we smile and laugh when we're terrified?|last=Inglis-Arkell|first=Esther|date=7 October 2013|website=Gizmodo|access-date=7 October 2016}}</ref>

== Social effects ==
'''Smiling''' seems to have a favorable [[Social influence|influence]] upon others and makes one ''likable'' and more ''approachable''.<ref>{{cite journal |last=Gladstone |first=G. |title=When you're smiling, does the whole world smile for you? |journal=Australasian Psychiatry |year=2002 |volume=10 |issue= 2|pages=144–146 |doi=10.1046/j.1440-1665.2002.00423.x|s2cid=145551014 |doi-access= }}</ref> In the social context, smiling and [[laughter]] have different functions in the order of sequence in social situations:
* Smiling is sometimes a pre-laughing device and is a common pattern for paving the way to laughter;
* Smiling can be used as a response to laughter.<ref>{{cite journal |last=Haakana |first=M. |title=Laughter and smiling: Notes on co-occurrences |journal=Journal of Pragmatics |year=2010 |volume=42 |issue=6 |pages=1499–1512 |doi=10.1016/j.pragma.2010.01.010 }}</ref>

=== As reinforcement and manipulation ===
The influence of smiling on others is not necessarily benign. It may take the form of [[positive reinforcement]], possibly for an underhand [[Psychological manipulation|manipulative]] and [[abusive]] purpose.<ref name=braiker>{{Cite book|title=Who's Pulling Your Strings ? How to Break The Cycle of Manipulation |first=Harriet B.|last=Braiker |year=2004 |publisher=McGraw Hill Professional |isbn=978-0-07-144672-3}}</ref>

== Cultural differences ==
While smiling is perceived as a positive [[emotion]] most of the time, there are many [[cultures]] that perceive smiling as a negative expression and consider it unwelcoming. Too much smiling can be viewed as a sign of shallowness or [[dishonesty]].<ref>{{cite web|author=Charles Tidwell |url=http://www.andrews.edu/~tidwell/bsad560/NonVerbal.html |title=Non Verbal Communication |publisher=Andrews.edu |access-date=2014-04-22}}</ref> In some parts of [[Asia]], people may smile when they are embarrassed or in emotional pain. Some people may smile at others to indicate a friendly greeting. A smile may be reserved for close friends and family members. Many people in the [[former Soviet Union]] area consider smiling at strangers in public to be unusual and even suspicious behavior,<ref>{{cite web|url=http://www.rpi.edu/dept/advising/american_culture/social_skills/nonverbal_communication/reading_exercise.htm |title=Nonverbal Communication |publisher=Rpi.edu |access-date=2014-04-22}}</ref> or even a sign of stupidity.<ref>{{cite news|url=http://www.bbc.com/future/story/20170407-why-all-smiles-are-not-the-same|title=There are 19 types of smile but only six are for happiness|work=[[BBC]] Future|first=Zaria|last=Gorvett|date=10 April 2017}}</ref>

Systematic large cross-cultural study on social perception of smiling individuals<ref>{{Cite journal|last1=Krys|first1=Kuba|last2=-Melanie Vauclair|first2=C.|last3=Capaldi|first3=Colin A.|last4=Lun|first4=Vivian Miu-Chi|last5=Bond|first5=Michael Harris|last6=Domínguez-Espinosa|first6=Alejandra|last7=Torres|first7=Claudio|last8=Lipp|first8=Ottmar V.|last9=Manickam|first9=L. Sam S.|date=June 2016|title=Be Careful Where You Smile: Culture Shapes Judgments of Intelligence and Honesty of Smiling Individuals|journal=Journal of Nonverbal Behavior|volume=40|issue=2|pages=101–116|doi=10.1007/s10919-015-0226-4|issn=0191-5886|pmc=4840223|pmid=27194817}}</ref> documented that in some cultures a smiling individual may be perceived as less intelligent than the same non-smiling individual (and that cultural uncertainty avoidance may explain these differences). Furthermore, the same study showed that corruption at the societal level may undermine the prosocial perception of smiling—in societies with high corruption indicators, trust toward smiling individuals is reduced.

There can also be gender differences. In the United States and Canada, women report men telling them to smile. For example, [[Greg Rickford]], a member of the Canadian Parliament, told a female journalist to smile rather than answer the question she had asked.<ref>{{Cite journal|last1=Laing|first1=Sarah|date=July 25, 2018|title=Why Do Men Need Women To Smile?|journal=Flare|url=https://www.flare.com/news/greg-rickford-marieke-walsh-smile-women/|access-date=2020-09-22|archive-date=2020-10-01|archive-url=https://web.archive.org/web/20201001165500/https://www.flare.com/news/greg-rickford-marieke-walsh-smile-women/|url-status=dead}}</ref> Biological anthropologist [[Helen Fisher (anthropologist)|Helen Fisher]] states that, while this could be either caring or controlling behavior, such behavior is unlikely to be welcome.<ref>{{Cite journal|last1=May|first1=Ashley|date=March 2017|title=Why you shouldn't tell a woman to smile|journal=USA Today|url=https://www.usatoday.com/story/news/nation-now/2017/03/08/dont-tell-women-to-smile/98906528/|access-date=2020-09-22}}</ref>

{{Gallery
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|File:Gerrit van Honthorst - Smiling Girl, a Courtesan, Holding an Obscene Image - 63-1954 - Saint Louis Art Museum.jpg|''[[Smiling Girl, a Courtesan, Holding an Obscene Image]]'' (1625) by [[Gerard van Honthorst]]. Humor has been noted as a source of inspiration for many notable [[Dutch Golden Age painting|Dutch Golden Age]] painters.<ref>{{cite news|url=https://www.nytimes.com/2017/10/21/arts/humor-17th-century-dutch-art.html|title=Need a Good Laugh? Check Out Some 17th-Century Dutch Art |date=October 21, 2017|last=Siegal|first=Nina|newspaper=[[The New York Times]]|access-date=October 20, 2023}}</ref>

|File:Madame Vigee-Lebrun and her daughter, Jeanne Lucia (Julie).jpg|In her ''Self-portrait with her daughter Julie'' (1786), [[Élisabeth Vigée Le Brun]] painted herself smiling. When it was exhibited at the [[Salon of 1787]], the court gossip-sheet {{lang|fr|[[Mémoires secrets]]}} commented: "An affectation which artists, art-lovers and persons of taste have been united in condemning, and which finds no precedent among the Ancients, is that in smiling, [Madame Vigée LeBrun] shows her teeth."<ref>{{cite book|title=The Great Nation: France from Louis XIV to Napoleon|last=Jones|first=Colin|publisher=Penguin Books|location=London|date=2003|page=364|isbn=9780140130935}}</ref>

|File:'Willy' smiling. Mary Dillwyn Col. 1853.jpg|A photograph of a [[Welsh people|Welsh]] boy, William Mansel (1838–1866), titled 'Willy', smiling at something off camera. Taken {{circa|1853}}, it is the earliest known photograph of a smile.<ref>https://www.library.wales/discover-learn/digital-exhibitions/photographs/early-swansea-photography/welsh-pioneers/|title=Swansea{{Dead link|date=July 2024 |bot=InternetArchiveBot |fix-attempted=yes }} in the nineteenth century, Welsh Pioneers.</ref><ref>{{cite web | url=https://diff.wikimedia.org/2015/09/18/first-smile-photobomb-wales/#:~:text=Willy%20is%20looking%20at%20something,1853%2C%20when%20he%20was%2018 | title=The first smile and photobomb ever photographed | date=18 September 2015 }}</ref>

|File:"No Lessons Today" - Flora Rankin, by Lewis Carroll (1863).png|Photograph taken by [[Lewis Carroll]] titled "No Lessons Today" (1863), depicting a child's feelings when school holidays begin. Carroll later sent the photograph to [[Charles Darwin]] for possible use in his publication ''[[The Expression of the Emotions in Man and Animals]]''.<ref>{{cite book|last1=Wakeling|first1=Edward|title=Lewis Carroll: The Man and his Circle |url=https://books.google.com/books?id=OMLFBQAAQBAJ|year=2014|isbn=978-1780768205|page=164|publisher=[[I.B. Tauris]]}}</ref>
|File:Eating rice, China - collected by Berthold Laufer.jpg|In the late 19th century and early 20th century, photographs taken in the [[United Kingdom]] rarely depicted people smiling, in accordance with the cultural conventions of Victorian and Edwardian society. In contrast, the photograph ''Eating Rice, China'' depicts a smiling Chinese man.<ref>{{cite web|last1=Edwards|first1=Phil|title=Why people never smiled in old photographs|url=https://www.vox.com/2015/4/8/8365997/smile-old-photographs|website=Vox|date=7 October 2016}}</ref>
}}

== Dimples ==
[[File:VirgilGriffithFace.jpg|thumb|A man with cheek [[dimples]] smiling.]]
[[Dimple|Cheek dimples]] are formed secondary to a bifid [[Zygomaticus major muscle|zygomaticus major]] muscle, whose fascial strands insert into the dermis and cause a dermal tethering effect.<ref>{{Cite journal |last1=Lari |first1=A. R. |last2=Panse |first2=Nikhil |date=January 2012 |title=Anatomical basis of dimple creation - A new technique: Our experience of 100 cases |journal=Indian Journal of Plastic Surgery|volume=45 |issue=1 |pages=89–93 |doi=10.4103/0970-0358.96593 |issn=1998-376X |pmc=3385407 |pmid=22754160 |doi-access=free }}</ref>  Dimples are genetically inherited and are a dominant trait.<ref>{{Cite journal |last1=Chalathadka |first1=Mahabaleshwara |last2=Shankar |first2=K Kiruba |last3=Lakshmi |first3=G Vijaya |last4=Nithin |first4=VM |last5=Kulkarni |first5=Sneha |last6=Firdousbano |first6=Mulla |date=2019 |title=Evaluation of Prevalence and Morphology of Dimple among Population of Sullia Taluk |journal=Journal of Cutaneous and Aesthetic Surgery |volume=12 |issue=4 |pages=227–230 |doi=10.4103/JCAS.JCAS_109_19 |issn=0974-2077 |pmc=6967164 |pmid=32001967 |doi-access=free }}</ref> Having bilateral dimples (dimples in both cheeks) is the most common form of cheek dimples.<ref name="surgery">{{cite journal|last1=Almaary|first1=Hayaat F.|last2=Scott|first2=Cynthia|last3=Karthik|first3=Ramakrishnan|title=New Landmarks for the Surgical Creation of Dimples Based on Facial Form|journal=The Journal of Clinical and Aesthetic Dermatology|volume=11|issue=5|pages=22–26|pmc=5955629|year=2018|pmid=29785234}}</ref> A rarer form is the single dimple, which occurs on one side of the face only.

This bifid variation of the muscle originates as a single structure from the [[zygomatic bone]]. As it travels anteriorly, it then divides with a superior bundle that inserts in the typical position above the corner of the mouth. An inferior bundle inserts below the corner of the mouth. Dimples are [[analogy (biology)|analogous]] and how they form in cheeks varies from person to person. The shape of a person's face can affect the look and form as well:<ref name="surgery"/> leptoprosopic (long and narrow) faces have long and narrow dimples, and eryprosopic (short and broad) faces have short, circular dimples.<ref name="surgery"/> People with a mesoprosopic face are more likely to have dimples in their cheeks than any other face shape.<ref name="surgery"/>

== Duchenne smile ==
[[File:Smiling girl.jpg|thumb|A Duchenne smile engages the muscles around the mouth and eyes.]]
While conducting research on the [[physiology]] of facial expressions in the mid-19th century, French neurologist [[Guillaume Duchenne de Boulogne|Guillaume Duchenne]] identified two distinct types of smiles. A Duchenne smile involves contraction of both the [[zygomaticus major muscle|zygomatic major muscle]] (which raises the corners of the mouth) and the [[orbicularis oculi muscle]] (which raises the cheeks and forms [[wrinkle (skin)|crow's feet]] around the eyes). The Duchenne smile has been described as "smizing", as in "smiling with the eyes".<ref>{{cite book|last1=Davis|first1=Darryl|title=How to Design a Life Worth Smiling About: Developing Success in Business and in Life|publisher=McGraw Hill Professional|isbn=9780071819879|page=8|url=https://books.google.com/books?id=DHbhAgAAQBAJ&pg=PA8|date=2014-05-30}} {{subscription required|s}}</ref> An exaggerated Duchenne smile is sometimes associated with lying.<ref>{{Cite web|url=https://www.theweek.co.uk/93854/how-facial-software-can-identify-liars|title=How facial software can identify liars|website=The Week UK|date=24 May 2018 }}</ref>

== Non-Duchenne smile ==
A non-Duchenne smile involves only the zygomatic major muscle.<ref>Duchenne, Guillaume (1990). ''The Mechanism of Human Facial Expression''. New York: Cambridge University Press. Translated by R. Andrew. Originally published as ''Mecanisme de la Physionomie Humaine'' in 1862.</ref> According to Messenger ''et. al.'', "Research with adults initially indicated that joy was indexed by generic smiling, any smiling involving the raising of the lip corners by the zygomatic major .... More recent research suggests that smiling in which the muscle around the eye contracts, raising the cheeks high (Duchenne smiling), is uniquely associated with positive emotion."<ref>{{cite journal |last1=Messinger |first1=D. S. |last2=Fogel |first2=A. |last3=Dickson |first3=K. |year=2001 |title=All smiles are positive, but some smiles are more positive than others |journal=[[Developmental Psychology (journal)|Developmental Psychology]] |volume=37 |issue=5 |pages=642–653 |doi=10.1037/0012-1649.37.5.642 |pmid=11552760 |citeseerx=10.1.1.502.9428 }}</ref>

The "Pan Am smile", also known as the "[[Botox]] smile", is the name given to a fake smile, in which only the zygomatic major muscle is voluntarily contracted to show politeness. It is named after the now-defunct airline [[Pan American World Airways]], whose flight attendants would always flash every passenger the same perfunctory smile.<ref name="Panam">{{cite news|last=Harlow|first=John|title=The smile that says where you're from|url=http://www.timesonline.co.uk/tol/news/uk/article516707.ece|access-date=18 January 2011|newspaper=The Sunday Times|date=February 20, 2005 |url-status=dead |archive-url=https://web.archive.org/web/20110629135410/http://www.timesonline.co.uk/tol/news/uk/article516707.ece |archive-date= Jun 29, 2011 }}</ref> Botox was introduced for cosmetic use in 2002.<ref>{{cite news|last=Fischer|first=Andrea|title=FDA approves Botox Cosmetic to improve the appearance of crow's feet lines|url=https://www.fda.gov/newsevents/newsroom/pressannouncements/ucm367662.htm |website=FDA |access-date=3 November 2013|date=11 September 2013 |url-status=dead |archive-url=https://web.archive.org/web/20131108213809/https://www.fda.gov/newsevents/newsroom/pressannouncements/ucm367662.htm |archive-date= Nov 8, 2013 }}</ref> Chronic use of Botox injections to deal with eye wrinkles can result in paralysis of the small muscles around the eyes, preventing the appearance of a Duchenne smile.

== Other animals ==
[[File:Knoxville zoo - chimpanzee teeth.jpg|thumb|Chimpanzee "smiling" at [[Zoo Knoxville]].]]
In other animals, the baring of teeth is often used as a [[threat display|threat or warning display]]—known as a [[snarl]]—or a sign of [[submission]]. For [[Common chimpanzee|chimpanzees]], it can also be a sign of [[fear]]. However, not all animal displays of teeth convey negative acts or emotions. For example, [[Barbary macaque]]s demonstrate an open mouth display as a sign of playfulness, which likely has similar roots and purposes as the human smile.<ref name="smile">{{cite journal | last1 = Preuschoft | first1 = Signe | year = 1992 | title = 'Laughter' and 'Smile' in Barbary Macaques (''Macaca Sylvanus'') | journal = Ethology | volume = 91 | issue = 3| pages = 220–36 | doi = 10.1111/j.1439-0310.1992.tb00864.x }}</ref>

== See also ==
<!-- new links in alphabetical order please -->
{{columns-list|colwidth=20em|
*[[Facial Action Coding System]]
*[[Frown]]
*[[Praise]]
*[[Say cheese]]
*[[Smiley]]
*[[Pleasure]]
}}

== References ==
{{Reflist}}

== Further reading ==
* {{cite journal | last1 = Conniff | first1 = Richard |author-link=Richard Conniff| year = 2007 | title = What's behind a smile? | url =http://connection.ebscohost.com/c/articles/25895270/whats-behind-smile | journal = [[Smithsonian Magazine]] | volume = 38 | pages = 46–53 }}{{dead link|date=January 2025|bot=medic}}{{cbignore|bot=medic}}
* Ottenheimer, H.J. (2006). ''The anthropology of language: An introduction to linguistic anthropology.'' Belmont, CA: Thomson Wadsworh. {{ISBN|978-1111828752}}
* {{cite journal | last1 = Ekman | first1 = P. | last2 = Davidson | first2 = R.J. | last3 = Friesen | first3 = W.V. | year = 1990 | title = The Duchenne smile: Emotional expression and brain psysiology II. | journal = Journal of Personality and Social Psychology | volume = 58 | issue = 2| pages = 342–353 | doi = 10.1037/0022-3514.58.2.342 | pmid = 2319446 }} Cited in: Russell and Fernandez-Dols, eds. (1997).
* Russell and Fernandez-Dols, eds. (1997). ''The Psychology of Facial Expression''. Cambridge. {{ISBN|0-521-58796-4}}.

== External links ==
{{Commons category|Smiling}}
{{wikiquote}}
* [http://news.bbc.co.uk/1/hi/health/3105580.stm BBC News: Scanner shows unborn babies smile]

{{Authority control}}

[[Category:Facial expressions]]
[[Category:Laughter]]
[[Category:Mouth]]
[[Category:Happiness]]
[[Category:Social influence]]