- published: 20 Nov 2007
- views: 38719
A smile is a facial expression formed by flexing the muscles near both ends of the mouth. The smile can also be found around the eyes (see 'Duchenne Smiling' below). Among humans, it is an expression denoting pleasure, joy, happiness, or amusement, but can also be an involuntary expression of anxiety, in which case it is known as a grimace. Smiling is something that is understood by everyone despite culture, race, or religion; it is internationally known. Cross-cultural studies have shown that smiling is a means of communicating emotions throughout the world. But there are large differences between different cultures. A smile can also be spontaneous or artificial.
Many biologists think the smile originated as a sign of fear. Primalogist 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. Biologists believe the smile has evolved differently among species and especially among humans.