According to new research published in the journal, Nature Communications, our perception of the truth is largely reliant on the patterns of stress and intonation exhibited by a speaker.
The aim of the analysis was to determine whether or not humans can detect a lie based on the qualities of its delivery alone. The study employed a massive, diverse participant sample before each was asked to record various true and untrue statements. These statements were subsequently placed into two separate groups: certain/honest or uncertain/dishonest. Respondents waited one week between recording their statements and characterizing the statements of others.
The researchers from Sorbonne University behind the new report concluded that lower speech with reduced emphasis on the middle of a word shared the closest association with lying of all the patterns reviewed. This remained true among English, French and Spanish participants alike.
The author even used different acoustic dimensions in order to root out any mitigating factor. Speech pattern was routinely the most relevant condition.
In linguistics, the particular manner in which a person’s voice rises and falls is referred to as their prosodic signature. A speech pattern that features an eclectic mix of inflections would be said to be high in prosody. More casually, this speaking style often takes on a musical constitution; think of the way you might talk to your dog or Gary Busey.
Low prosody could be described as deadpan or deliberate. Like the speaker is thinking very carefully about each word in a sentence.
“The success of human cooperation crucially depends on mechanisms enabling individuals to detect unreliability in their conspecifics. Yet, how such epistemic vigilance is achieved from naturalistic sensory inputs remains unclear. Here we show that listeners’ perceptions of the certainty and honesty of other speakers from their speech are based on a common prosodic signature,” the authors wrote in the new report.
“Using a data-driven method, we separately decode the prosodic features driving listeners’ perceptions of a speaker’s certainty and honesty across pitch, duration, and loudness. We find that these two kinds of judgments rely on a common prosodic signature that is perceived independently from individuals’ conceptual knowledge and native language. Finally, we show that listeners extract this prosodic signature automatically and that this impacts the way they memorize spoken words.”
Speakers who began their statements with subdued intensity continued with a rising intonation, and spoke slowly with varied pitch were frequently characterized as lying. This is likely because it takes more effort for our brains to conceive a lie than it does for it to articulate the truth. The surprising thing, however, was that the human brain is biologically poised to pick up on subtle prosodic changes.
“Taken together, these two separate strands of literature suggest that a common, core prosodic signature of cognitive effort may in fact support both social perceptions of certainty and honesty,” the authors continued.
Independently conducted research has suggested that committing to deception takes up a lot of cognitive space because we’re instinctively prone to telling the truth. The end result means we don’t have enough of our facilities left to choreograph natural responses to progressive dialogue when lying for long periods of time.
“These findings shed light on a unique auditory adaptation that enables human listeners to quickly detect and react to unreliability during linguistic interactions,” the authors concluded.
“Despite the fact that both tasks (certainty/honesty) were separated by an interval of 1 week, and the large variety of random tokens presented to the listeners, we found that the perceptual representations obtained for honesty and certainty were strikingly similar for all three acoustic dimensions.”
It should be noted that former CEO and founder Elizabeth Holmes, who is pleading not guilty to wire fraud charges alleging that her Theranos technology could perform functions with a single drop of blood that it actually could not execute, spoke in a lower-tone voice that was believed to be manipulated.
She changed her voice to come off as more powerful, as studies have shown that a lower voice is perceived as more authoritative. However, perhaps she did it because she was consistently lying and had to carefully think about what she was saying.
Jillian O’Connor, an assistant professor of psychology at Concordia University who studies how voices have influence, told The Cut, “This whole [Holmes] situation, the image manipulation, dressing like Steve Jobs, trying to sound a particular way — it sounds like an awful lot went into the facade. “