What is the best way to unmask a liar? Obviously, each of us use very different tactics; Vrij, a professor at the University of Portsmouth, has shown that the best way to detect a liar is to make him repeat his version of the events as they occurred at the contrary, which it means, make him tell the story of the event beginning from the latest situation to the more remote.
This idea is based on the theory that lying is quite more difficult, from a cognitive point of view, while telling the story in reverse. The number of errors and inconsistencies increases considerably.
The study in question was developed by asking 290 policemen to examine 255 students through an interview in which the students had to answer with real or fake data to the respective questions.
The policemen were more capable detecting lies when the interview technique demanded the story being told backwards compared to the classic interrogation techniques.
People who lie tend to tell their story following a strict chronological order, precisely because they know they must be coherent and not contradictory, so when asked to vary the order of the story the cognitive load gets heavy causing severe stress to liars.
Of course, this technique shouldn’t be considered perfect, there are always factors such as stress, intellectuals limits or emotional state, that can make seem fake even a true story. Telling stories in reverse is only one procedure more to detect the possibility that a person is lying but it doesn’t guarantee anything at all.
Source:
Vrij, A. (2000) Detecting Lies and Deceit: The Psychology of Lying and Implications for Professional Practice. Chichester: John Wiley & Sons.
