How do you recognize a real or fake smile?

Written by Claudio Pasque, on blog Gravita Zero, November 9th 2010.
Translated by Michael Mottola. See the original article in Italian
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Anyone who watches Dr. House knows how the famous doctor is skilled at interpreting body language and understanding when someone is lying. Something that works in his favor and which gives him great enjoyment.
But would you be able to tell when a person is lying?

Now you can test your skills with “Spot the Fake Smile“, an experiment that allows you to identify real and fake smiles.
It was designed by Paul Ekman, a psychology professor at the University of California, who spent a good portion of his career studying facial expressions.
I was able to guess 18 out of the 20 smiles correctly! A useful skill to have if I were a poker player! :-)

I erased the answers so you can try too.

Even though fake smiles are often similar to the real ones, in reality they are slightly different because they are generated by different types of facial muscles, controlled by a different part of the brain.
Fake smiles are executed by a conscious part of our brain by stimulating the zygomatic muscles that contract the cheeks: these are the muscles that pull the corners of the mouth in an external direction.

On the other hand, real smiles are generated unconsciously, making them automatic. When people feel pleasure, signals are transmitted through the part of the brain that processes emotion. In addition to causing movement in the muscles of the mouth, the muscles that raise the cheeks activate the orbital muscles, causing the eyes and the eyebrows to fold.
Researchers are capable of recognizing when a person is lying with the Facial Action Coding System (FACS), which was developed by Professor Paul Ekman and Dr. Wallace V. Friesen of the University of Kentucky.