HAND gestures and hesitations – common traits when someone is lying – happen more often when people are telling the truth, according to a new study.

Psychologists at the University of Edinburgh said tests revealed that people are skilled at identifying such signals and liars are equally skilled at suppressing them to avoid detection.

They used an interactive game to assess the types of speech and gestures speakers produce when they are telling fibs, and the clues listeners interpret as evidence that a statement is false.

Edinburgh University researcher, Jia Loy, created a computerised two-player game in which two dozen players hunted for treasure – and were free to lie as they did so.

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

There were analysed to see which of them listeners identified, and which were more likely to be produced when telling an untruth.

The team found listeners were efficient at identifying these signs – making judgements on whether something is true within a few hundred milliseconds of encountering a cue.

However, the team found that the common signs associated with lying were more likely to be used if the speaker is telling the truth. They say the study helps understand the psychological dynamics that shape deception.

Their study, published in the Journal of Cognition, said: “In terms of spoken cues, the best model for Speakers revealed pauses to be a significant predictor: Speakers were more likely to be telling the truth when their utterance contained a pause, either filled or silent.

“Although pauses also emerged as a significant predictor in the best Guesser model, this relationship was in the opposite direction: Guessers interpreted Speakers’ utterances containing pauses as untruthful.”

A further disconnect was seen in the pattern for gestures with speakers were more likely to use them in the context of a lie. Guessers, however, tended to infer falsehood from the absence of affect displays.

Dr Martin Corley, of the School of Philosophy, Psychology and Language Sciences, said: “The findings suggest 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.”