An article on Social Intelligence – Observing Nonverbal Behavior and Understanding Emotions – by Dr. Sandeep Atre.
Psychologists Craig Smith and Heather Scott put it brilliantly – “Face has the only skeletal muscles of the body that are used, not to move ourselves, but to move others”.
During Iraq war, US Army’s 3rd Infantry entered the town of Najaf. As soldiers marched towards a mosque, locals began to get anxious and started to gather. Seeing tension building up, Commander asked soldiers to point their guns to ground and simply…‘Smile’. And a serious clash got avoided.
So, what is it about this ‘curving of lips’ that transcends all barriers of language and culture and touches right there – where it feels the most! The truth is that smiles are not mere expressions; rather they are, as researcher Marianne LaFrance says, “social acts with consequences”.
We all know this, and that’s why people who primarily aim at generating positive consequences often have oversized smiles. Yes! Don’t just fall for those pearly-whites flashed at you. Such deliberate smiles are broad simply because their purpose is less to be felt and more to be seen.
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So, ‘width doesn’t necessarily involve depth’ – is first pointer regarding genuineness of smiles. More in my coming blog-posts… 
PS: All inputs on observing nonverbal behavior should be applied after establishing the baseline behavior.
Dr. Sandeep Atre
Founder Director, Socialigence – Developing Social Intelligence
Specialized Online Courses & Customized workshops on Observing Nonverbal Behavior and Understanding Emotions