Psychology

Clues that suggest lying may be deceptive

The verbal and physical signs of lying are harder to detect than people believe, a study suggests

Tests reveal that people are skilled at identifying commonly displayed cues – such as hesitations and hand gestures – but these signs are produced more often when someone is telling the truth. 

Liars are also skilled at suppressing these signals to avoid detection, researchers found.

Interactive game

Psychologists and linguists used an interactive game to assess the types of speech and gestures speakers produce when lying, and which clues listeners interpret as evidence that a statement is false.

Centre for Language Evolution researcher Jia Loy from the University created a computerised two-player game in which 24 pairs of players hunted for treasure.  Players were free to lie at will.

Coding behaviour

Researchers coded more than 1100 utterances produced by speakers against 19 potential cues to lying – such as pauses in speech, changes in speech rate, shifts in eye gaze and eyebrow movements.

The cues were analysed to see which ones listeners identified, and which cues were more likely to be produced when telling an untruth.

Common signs

The team found listeners were efficient at identifying these common signs.

Listeners make judgements on whether something is true within a few hundred milliseconds of encountering a cue.

However, they found that the common cues associated with lying were more likely to be used if the speaker is telling the truth.

Researchers say the study helps to understand the psychological dynamics that shape deception.

The findings suggests that we have strong preconceptions about the behaviour associated with lying, which we act on almost instinctively when listening to others. However, we don't necessarily produce these cues when we’re lying, perhaps because we try to suppress them.

Martin CorleySchool of Philosophy, Psychology and Language Science

The study is published in the Journal of Cognition.

Link to study

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