Research Observations About Lying

Liars

It was found that common observations and discoveries about what liars do are as follows (with potential motivations added):

Reduce the chances of slipping up by saying noticeably less rather than more.

Feel guilty, so add justification without being prompted.

Gain time by repeating questions asked of them and then speaking slowly.

When they gain confidence, speaking faster to avoid suspicion, get things over and done with, or to block challenges.

Watch you carefully to see if you have accepted their story.

Be thinking hard at the same time as speaking and so make verbal slips such as using sentence fragments and going back to correct themselves.

Indicate unwillingness to answer sensitive questions by pressing their lips together.

Feel stressed and so touch themselves in comforting grooming gestures.

Feel the need to protect themselves and so move their hands towards their body.

When asked a difficult question will look away (as truthful people will) then quickly look back to monitor how you are observing them.

Truth-tellers

People who are telling the truth are effectively the opposite of the above, and so may:

Speak at length, with comfort.

Speak at a consistent speed which is their normal rate.

Do not feel the need to justify what they are saying.

Feel comfortable and gesture outwards.

Look away to think about a difficult question.

Techniques for getting to the truth

The conclusions for getting to the truth are that you should:

Encourage them to speak more, for example by asking open questions.

Do not interrupt them. Let them talk and encourage continuation, for example with pauses.

Ask them to tell their stories backwards to increase the cognitive load (possibly overloading them).

Liars