In my last blog post I discussed functional MRI and how it could be used to determine if someone was lying. Maybe. School isn’t out on that yet. Regardless, this rather high-tech lie detection method requires very expensive equipment and professional expertise to run the MRI machine and interpret the data. But Aldert Vrij of the University of Portsmouth in the UK may have come up with a clever, low-tech device.
He simply asked the question: Would a liar sketch a scene differently from someone who is telling the truth? To answer this question, he designed a very simple yet clever experiment. Using 31 volunteers, he sent them on a mission to collect a laptop from an actor who posed as a secret agent. Once they secured the laptop they were to deliver it to another agent at a different location. The second agent asked them to describe the scene where they received the laptop and to sketch it in detail. Previously half of the volunteers were told to tell the truth and the other half were told to lie about this event.
The results were interesting. Twelve of the 15 who told the truth sketched the scene and included the first agent in their drawing while only two of 16 liars included the agent. This was probably because they were recalling someplace that they knew well while they were making the sketch and since they knew that area without an agent being present they simply neglected to add him to the scene.
There was also a difference in perspective among the drawings. The liars tended to take a birds eye view in that they drew the scene from above much as if looking at a map. The truth tellers on the other hand drew the scene as they saw it from a first-person perspective. This makes sense since they were drawing what they actually saw while the liars were making up a drawing and therefore took a more global perspective.
This technique is undergoing further study and it will be interesting to see if it pans out. It would be very useful to have some low-tech and inexpensive way of determining whether someone was lying or being truthful.