The Definitive Book of Body Language

The Definitive Book of Body Language

than the other, as both sides of the brain attempt to make it

appear genuine. The half of the brain's cortex that specialises

in facial expressions is in the right hemisphere and sends

signals mainly to the left side of the body. As a result, false

facial emotions are more pronounced on the left side of the

face than the right. In a real smile, both brain hemispheres

instruct each side of the face to act with symmetry.

When liars lie, the left side of the smile is

usually more pronounced than the right

Smugglers Smile Less

We were commissioned by Australian Customs, in 1986, to
help create a programme to increase the number of seizures of
illegal contraband and drugs being smuggled into Australia-
Until that time, it had been assumed by law enforcement offi-
cers that liars increased their frequency of smiling when they
were lying or under pressure. Our analysis of film of people
who were intentionally told to lie showed the opposite - when
the liars lied, they smiled less or not at all, regardless of
culture. People who were innocent and telling the truth
increased their smiling frequency when being honest. Because
smiling is rooted in submission, the innocent people were
attempting to appease their accusers while the professional
liars were reducing their smiles and other body signals. It's the