How to spot a liar: people tend to speak more slowly and place less emphasis in the middle of words when they tell a fib, the study finds
- Researchers compiled voices that say words in different tones and pitches
- It was to mimic the ‘sound signature’ people use when they lie or are honest
- They then had volunteers listen to sounds and regard words as honest or dishonest
- They spoke more slowly and less emphasis was a sign of dishonesty
If someone tells a lie, it is possible to catch them out, as they are more likely to speak slowly and place less emphasis in the middle of words, according to a study.
Researchers at the Sorbonne University conducted a series of experiments to understand how we, based on voice alone, decide whether a speaker is honest.
They found that there was a signature in the voice of a liar – slower speech and less emphasis on the middle of a word – that the brain can automatically detect – even if he is not actively trying to determine if someone is honest or not .
It is hoped that in the future, the discovery could be used to develop ‘light tools’ that police could use to determine if a criminal was lying.
Researchers at the Sorbonne University conducted a series of experiments to understand how we, based on voice alone, decide whether a speaker is honest. Stock image
Study authors say that if you want to be honest and confident, then speak faster, place greater intensity in the middle of a word and drop the pitch at the end.
These subtle changes in the way we speak are ‘automatically’ registered by the brain and occur in a number of languages, including English, French and Spanish.
The French researchers used the processing of vowel signal to create random pronunciations of words, including ascending and descending pitches.
They then asked various groups of volunteers whether the words were pronounced with certainty or with honesty.
The success of human collaboration depends on mechanisms that enable individuals to detect unreliability in the people they regularly deal with.
Despite being an important part of human society, researchers do not know exactly what sensory inputs people use to determine the reliability of another.
To work this out, the French researchers used a data-driven method to decode the prosodic features that increase listeners’ perception of a speaker’s certainty and honesty throughout the pitch and loudness.
“Here it is shown that the perception of listeners about the certainty and honesty of other speakers from their speech is based on a general prosody signature,” they said.
Study authors say that if you want to be honest and confident, then speak faster, place greater intensity in the middle of a word and drop the pitch at the end. Stock image
Prosody refers to the ‘melody’ of a phrase or word: its pitch, tempo and intensity.
‘We find that these two types of statements [certainty and honesty] rely on a general prosodic signature that is perceived independently of the conceptual knowledge and mother tongue of individuals, ‘the authors of the study wrote.
‘Finally, we show that listeners automatically retrieve this prosodic signature and that it affects the way they memorize spoken words.
“These findings shed light on a unique auditory adaptation that enables human listeners to quickly notice and respond to unreliability during language interactions.”
They found that this ‘intrinsic’ ability to detect ‘signatures’ in a voice could be used to determine whether the person is telling the truth or peddling pigs.
“Prosody therefore carries information about the truth value or certainty of a statement,” the team wrote.
They are now trying to understand how speakers produce such prosody based on their intentions – rather than just how people experience different pronunciations.
The findings were published in the journal Nature Communications.