A smile is a face made by flexing the muscles near both ends of the mouth. The smile can also be made through the eyes (See 'Duchenne smile' below). Smiles usually show happiness. A smile can be natural or fake. However, smiling can be different with animals. When smiling, the teeth shows, but sometimes animals do this when they are threatening. When chimpanzees show their teeth, it can also be a sign of fear.
Dimples are genetically inherited. They are caused by the flesh underneath the skin, that forms on some people's cheeks, especially when they smile. Some people may only have one dimple on only one side of the face.
Although there are many different types of smiles, researchers are interested in the duchenne smile because it is done with the eyes. The Duchenne smile was named after the French physician Guillaume Duchenne. Duchenne identified two types of smiles. A Duchenne smile is when the cheek raises and forms a wrinkle around the eyes. Many researchers think that Duchenne smiles are usually hard to make when you are pretending to smile.
On the Internet, smiles can normally be typed up. This is normally called a smiley, smiley face, or happy face. Smileys show emotion when people are not able to see it in real life. Smileys typed on the computer are called emoticons. Smileys can change depending on where the person typing the smiley is.
Western Style: :-), :-(, ;-), :-O, :-D, (;D)
Eastern Style: d(^.^)b, \(^o^)/, >.<, ^_^, *<):)
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- Singapore Science Centre: ScienceNet|Life Sciences|Genetics/ Reproduction
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- Ottenheimer, H.J. (2006). The anthropology of language: An introduction to linguistic anthropology. Belmont, CA: Thomson Wadsworh.
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- Messinger D. & Fogel A. 2007. The interactive development of social smiling. In Robert Kail (ed) Advances in child development and behavior, 35, 327-366. Oxford: Elsevier. Retrieved 25 June 2010 from 
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