The Book of Tells (Peter Collett)[unlocked]

LYING TELLS
• MULTIPLE CAUSES. People often make the mistake of
thinking that specific actions are clues to deception, and
not to anything else. It is sometimes assumed, for
example, that people who touch their nose while they're
talking are automatically telling a lie; that the gesture is a
sign of lying, and nothing else. These assumptions overlook
the fact that actions and utterances may sometimes
provide clues to deception, while on other occasions
they may provide clues to states of mind that have
nothing to do with deception. People who rely on the
polygraph lie detector often make this mistake. The polygraph
measures respiration, heart rate and palmar
sweating - all of which are indicators of arousal. When
people become anxious, their breathing rate increases,
their heart rate goes up, and their palms start to sweat
more profusely. When people are lying they often
become anxious, and their anxiety can be detected by
the polygraph. However, there are times when people
become anxious without lying, just as there are cases
where people lie without experiencing any anxiety at all.
• LOOKING ELSEWHERE. People also fail to detect lies
because they are looking for clues in the wrong place.
Where people look is usually determined by what they
believe are the giveaway signs of lying. If you ask people
how they can tell if someone is lying to them, they
usually mention shifty eyes or the way people fidget with
their hands. The other signs of dishonesty that people
mention include smiling, rapid blinking, long pauses,
and talking too fast or too slow. Some of these behaviours
have in fact been found to be clues to deception, but
many are not. When Robert Krauss and his colleagues at
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