When a person is lying, it is possible to know it thanks to certain signals, such as the sound of their voice, their gaze or their gestures, which can betray them. Recently, a team of researchers revealed a new method to detect the lies of its interlocutor.
- In order for the interviewee to really take the extra instruction or task seriously, they need to be told that it is important or given a task that they cannot neglect, such as grasping an object, holding an object in the air or drive car simulator.
“There is evidence to suggest that lying is more cognitively demanding than telling the truth,” said scientists from the universities of Portsmouth in the UK and Florida in the US. In a recent study, they showed that recruiters who used this finding to their advantage by asking the candidate to perform an additional task during the interview were more likely to catch liars.
An experiment conducted with 164 people
As part of their work published in the journal International Journal of Psychology & Behavior Analysis, the authors wanted to examine the effect of performing a secondary task on the arguments of people who tell the truth and those who lie. For this, they recruited 164 people, whom they asked to put themselves in the conditions of an interview. Some had to tell the truth and others lie when answering questions on social issues.
Two-thirds of participants were also asked to recall and recall a car’s registration number during the interview. For a third of the participants, this additional instruction was made important. “The variables taken into account were the number of words spoken and the number of arguments reported as well as the plausibility, directness and clarity of the statement”, can we read in the study.
“Introducing an additional task made lie detection easier”
According to the results, recruiters who asked a candidate to perform an extra task while being interviewed were more likely to spot liars. According to the researchers, the extra brain power needed to focus on a secondary instruction or task (other than lying) was particularly difficult for people who lied.
“Introducing an additional task or instruction during the interview made it easier to detect lies. It seems that a secondary task is only effective if the liars don’t neglect it”, the scientists said.
