The Book of Tells (Peter Collett)[unlocked]

THE BOOK OF TELLS
point out that while a subordinate person needs to smile
to appease a dominant person, the dominant person is
'licensed' to smile when he or she likes. 12 The clue to why
the dominant person smiles more in a friendly situation
becomes clear when we look at the different ways that
people compose their facial features into a smile.
We all know that some smiles are genuine and others
are false. That's because we see people pretending to be
happy, and we know what it feels like to smile when we're
feeling miserable. Although we're constantly exposed to
fake smiles, and spend a great deal of our time producing
them for the benefit of other people, it's only since facial
expressions have been studied in detail that we have come
to understand what distinguishes a genuine smile from a
false smile.
One of the first scientists to tackle this issue was the
French anatomist, Guillaume Duchenne de Boulogne,
who published his Mécanisme de la physionomie
humaine in 1862, ten years before Darwin's book on the
face appeared. Duchenne was fascinated by the musculature
of the face - an interest he reputedly developed
while examining heads chopped off by the guillotine. He
was also the first person to apply electrical currents to the
face to see how the muscles worked. 13
Duchenne discovered that genuine smiles involve two
sets of muscles. The first is the zygomatic major muscles,
which run down the side of the face and attach to
the corners of the mouth. When these are contracted the
corners of the mouth are pulled up, the cheeks are puffed
up, and the teeth are sometimes exposed. The second set
of muscles, the orbicularis oculi, surround the eyes. When
these are contracted the eyes become narrow and 'crow's
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