It can be incredibly difficult to tell if you’re being lied to – even so-called “lie detector” machines struggle, as we found out in issue 8 of our e-magazine CURIOUS. Thankfully, a new study has come through with a relatively simple tip to help us discern fact from fiction: look out for lack of detail.
Forget studying facial or verbal cues or attempts to catch your alleged liar out with distraction; focusing solely on the level of detail in what people say may be the best tactic if you want to know if you’re being led up the garden path.
While assessing a wide range of behavioral cues might seem like the most reliable way to catch a liar, it could actually be making things harder, according to the researchers.
“This is nonsensical, because it’s an impossible task,” first author Bruno Verschuere said in a statement. “People can't assess all those signals in a short time, let alone integrate multiple signals into an accurate and truthful judgment.”
Instead, Verschuere and colleagues suggest, stick to just one signal.
“It feels very counterintuitive to just listen to what people are saying and not to pay attention to all kinds of other signals, such as how convincingly or emotionally someone conveys their story,” explained Verschuere.
“But people who tell the truth can give a rich description because they actually experienced the event, whereas although liars can come up with details, this increases their risk of being caught.”
To investigate, the team conducted a series of experiments. Participants were split into two groups, one guilty and one innocent. The guilty group were tasked with stealing an exam from a locker and later had to lie about this, while the innocent group spent time around campus. Over nine studies, another group of people had to assess whether the participants were being honest or deceptive about their whereabouts based on handwritten statements, video transcripts, videotaped interviews, and live interviews.
When they were free to use any cue to do this, the group performed at the chance level. But when told to base their decision only on the level of detail present in the accounts, including place, person, time, and location, they were better able to discriminate lies from the truth. For example, in one study, using multiple cues resulted in just 59 percent accuracy, compared to 66 percent when relying on a single cue.
So, next time you need to spot a liar, it might be wise to pay attention to the nitty gritty. The devil, it seems, really is in the detail.
The study is published in Nature Human Behaviour.