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May 28, 2011

Why we smile?

Grimacing monkey
A smile is a magical tool in human society. It helps in winning people’s hearts and draw sympathy and favor. Smiley and emoticon have become integral part of text messaging and chatting applications around the world. We feel quite better when somebody smiles at us and we smile in return. Smiling person is like and loved the most than the one who presses lips tightly and glares at you.

Why we smile at each other so instinctively i. e. without training, instruction or compulsion? The answer to this question is both exciting and bizarre. My very own hypothesis about its origin, briefly titled as "Harmless Teeth" is as following. Please don't forget read it till the end.

Very few of us might know that our primate cousins (apes and monkeys) also smile at each other. When two primates stand in front of each other or pass along side, they open their mouths slightly so that their teeth should get displayed. In their society, smiling has a lot to do with social harmony, dominance and survival. Smile has almost similar value in human society too.

Dr. Paul Ekman
expressing anger
By doing this, they make each other feel safe by passing a message, “Don’t be afraid! I’m not baring my teeth at you. I’m friendly!”. It's only the dominant male in their group who doesn't show his teeth to others. He uses his teeth only to bite and injure his sub-ordinates or rivals to proclaim his superiority or control.

In face-to-face encounter, direct eye contact made with enlarged eyeballs and pressed lips is a classical sign of threatening, intimidation or hostile intentions. If any person is confronting to such kind of eye contact made by others for a considerable amount of time, it’s assured that it would result in either running away or retaliation through Amygdala Hijack.

Elongated hostile gaze leads to parasympathetic distress and our primate cousins use same strategy smartly. Dominant male gorillas stare with hostile facial expressions to control a large group of sub-ordinates and to deter rebellions or rivals. It's a sort of territorial invasion with eyes and also an invitation to fight.

According to my hypothesis, ritual of smiling is comparatively less related with lips and teeth than eyeballs and gaze. Orbicular muscles (Orbicularis Occuli) around the eyes unconsciously contract while smiling to convey that an individual is afraid of other person(s) during face to face encounters, confrontations and interactions.

43 different facial muscles

Displaying teeth along keeping eyes smaller in appearance creates overall effect of harmless intentions. Otherwise, displaying teeth by opening lips but deliberately keeping eyes wide open at the same time simply looks comic, weird and frightening. Also, clenching jaws and displaying teeth by opening lips at the same time also doesn't create the expected effect of harmless intentions.

Additionally, contracted orbicular muscles help in protecting eyes from possible attack and also reverse the effect of the stronger, hostile and dominating gaze i. e. our eyeballs appear smaller than their normal size. Along with the same, separation of both lips and turning their corners upward might have evolved to enhance orbicular muscles (Orbicularis Occuli) contraction.

A thin band of Zygomatic muscles on both side of face arising from Zygomatic bone i. e. near the outer edges of eyebrows and merging into Orbicularis Oris muscles (circular muscles around lips) at both corners of mouth contracts and pulls the edges of lips upwards while we smile. Also the puffed cheeks due to this pull provide an additional protection to eyes.

Air hostesses smile a lot during the flight
to keep the distress low in the passengers.

Smiling or looking at the smiling faces associated with Endorphin (a neurotransmitter) secretion. It induces feeling of happiness in mind even if smile is genuine or fake one. We portray different kinds of smiles for expressing appeasement, acceptance, approachability, innocence, happiness, friendliness, agreeableness, fondness etc. All of these facial expressions are non-threatening for others.

Very shocking it might sound for most of us but we can portray 43 different kinds of smiles. Also, a smile is the most commercially capitalized aspect of the overall body language.

[#Special Note: This articled has been accepted by, translated into Spanish (EspaƱola) and posted on Evidentia University (Behavioral and Forensic Sciences) website. It's URL is]

Related Articles:
1) Why we wave hands at others? 2) Positive body language 3) Making true friends 4) Woman's courtship Body Language (Part 1) 5) Woman's courtship Body Language (Part 2) 6) Primary Attraction 7) Why we hug? 8) Genuine Smile 9) Child inside us 10) Importance of Touch 11) Asymmetrical Smile but not Contempt


  1. Great Stuff Dude...keep it up..Nice Explanantions

  2. Very interesting article. How nice when someone serves you smiling!

  3. Phenomenal, really funny.


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