How we change what others think, feel, believe and do
Paraverbal Indicators of Lying
When we think about detecting lies, many of us will think first of the indications found in body language. In addition there are verbal clues, which are in the actual words used, and paraverbal indicators which are related to the verbal channel but which cover non-word topics as below. Of these, Sporer and Schwandt (2006) found particular significance in pitch, response latency, speech errors and message duration.
When a person fears detection, then they may decide to speak less, consequently using shorter sentences and answering questions as briefly as possible.
On the other hand, they may increase the length of what they say in order to gain control and prevent the other person from asking difficult questions.
Every word that a person who is lying says is a possible problem as others might detect some falsehood. Shorter sentences may consequently reflect the more careful thinking that a liar has to use in order to sustain the accuracy of their storyline.
The liar may seek to achieve both short messages and long duration, for example by talking slowly and dragging out sentences through inserted pauses, 'ums' and so on.
Alternatively, if they are trying to use up the available time with a filibustering strategy, they may talk quickly in order to block any attempts at interruption by the other person.
When we pause in our speech there is an opportunity for the other person to interrupt and so take control of the conversation. In order to prevent this and sustain control, someone who is being deceptive may fill the gap with devices such as 'ummmm, 'aaahh' and so on. They may also look away to stop the other person sending visual signals that they wish to start speaking.
One way to get another person to talk is to pause or use silence as this creates a social tension that people will seek to fill. In effect, you are saying 'please help me as I have run out of things to say'. The liar may decide not to fall into this trap and simply refuse to respond (and in doing so fall into the secondary trap).
When people are tense, their vocal cords also tense up and the pitch of their voice will rise. If the liar is feeling this tension then their vocal pitch will go up.
Of course if the liar is relaxed then there will not be any pitch clues.
Liars may repeat what they have already said when they run out of things to say, simply repeating their previously rehearsed statements.
They may also use repetition as a form of emphasis in trying to put the questioner off the subject and prevent probing. Repetition can appear as a subtle beat across a period of speech.
On the other hand, if a query is repeated on different occasions, the liar may forget their previous statement and say something different.
Response latency is the delay between the question being asked and the other person replying. Liars need to think about what they are going to say as opposed to a truth-teller who simply remembers or responds without caution. Delays in response may thus be an indicator of deception.
When a person is tense or thinking about multiple things at once they may get their words mixed up. They may also be suffering from internal inhibition, where one part of the mind is trying to stop them from saying things.
The result of this can be that they do not pronounce words correctly or even use the wrong words. Sometimes they may even give the game away by accidentally telling the truth when they intended to lie (especially with short-word answers).
Watch for paraverbal signs as well as verbal and body language. Beware of taking one sign as being conclusive. All indicators are possibilities only. If you can see clusters and link them to particular questions or thought patterns then the likelihood of lying increases.
Sporer, S.L. and Schwandt, B. (2006). Paraverbal Indicators of Deception: A Meta-analytic Synthesis.