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May 28, 2011

Why we smile?

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

Why we smile at each other so obviously i. e. without training or compulsion? The answer 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. In their society, smiling has lot to do with social harmony, dominance and survival. When two primates stand in front of each other or pass along side, they open their mounts slightly so that their teeth should get displayed.

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 bearing 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 social situation, 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 eye contact made by others for a considerable amount of time, it’s assured that it would result in either running away or retaliation (limbic flight or fight response).

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 large group of sub-ordinates and to derogate rebellions or rivals. It's a sort of territorial invasion from a distance and also an invitation to fight.

According to my hypothesis, ritual of smiling is comparatively less related with lips and teeth than eye balls 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 confrontations, encounters and interactions.

Different Facial Muscles

Contracted orbicular muscles helps to protect eyes from possible attack and also reverse the effect of the stronger, hostile and dominating gaze i. e. our eyeballs appear smaller. In addition to the same, separation of both lips and turning their corners upward might have evolved to enhance orbicular muscles (Orbicularis Occuli) contraction.

Displaying teeth along with fearful gaze creates overall effect of harmless intentions. 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 so as to induce happy feelings in mind even if smile is genuine or fake. We portray different kinds of smiles for expressing 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.

[This articled has been translated into Spanish (Espanol) and posted on Club Del Lenguaje No Verbal/Club of Nonverbal Language - a Spanish portal on Body Language and Nonverbal Communication. URL:]

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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