If You Want to Catch a Liar, Make Him Draw

interrogationA man accused of a crime is brought into a police interrogation room and sits down at an empty table.  There’s no polygraph equipment in sight, and the typical two-cop questioning team isn’t in the room either.  Instead, one officer enters the room with a piece of paper and a pencil in his hands. He sets them in front of the suspect, steps back, and calmly says, “draw.”

That’s a greatly oversimplified description of what could happen in actual interrogation rooms if the results of a recent study in the journal Applied Cognitive Psychology are widely adopted. The study is the first to investigate whether drawing is an effective lie detection technique in comparison to verbal methods.

Researchers hypothesized that several tendencies would become evident in the scribbles and sketches of liars not found in those of non-liars. For instance, they suspected that liars, when asked to sketch out the particulars of a location where they hadn’t really been to meet someone they hadn’t really met, would provide less detail in their drawings. They also suspected that the drawing would seem less plausible overall, and would not include a depiction of the person they allegedly met.  

Finally, they hypothesized that non-liars would use a “shoulder-camera” perspective to draw the situation – a direct, line-of-sight view that previous research suggests is more indicative of truth telling. Liars, they suspected, would use an “overhead-camera” perspective, indicating a sense of detachment from the situation.  

Subjects were given a “mission” that included going to a designated location and meeting a person with whom they would exchange information. In all, four different missions were conducted. The particulars of the missions were constructed such that about half of the participants would, when interviewed, be able to tell the truth about what happened, and half would have to lie (the researchers used a fabricated espionage theme to work this out – very clever).

During the interview, subjects were asked questions about their experience, as would happen in a normal interrogation, and also asked to draw the particulars of their experience.  Results of the verbal responses could then be compared to the drawn responses to determine which were more effective in identifying liars.

Here’s what happened: No significant differences in level of detail were found between verbal and drawn statements, but the plausibility of truthful drawings was somewhat higher than deceptive drawings. A similar difference in plausibility was not evident between truthful and deceptive verbal statements.

More interestingly, significantly more truth tellers included the “agent” (other person in the situation) in their drawings than did liars (80% vs. 13%).  In addition, significantly more truth tellers drew from a shoulder-camera view than liars, who by in large drew from an overhead view (53% vs. 19%). In verbal statements, more truth tellers also mentioned the agent (53%) than liars (19%).

Using the “sketching the agent” result alone, it was possible to identify 80% of the truth tellers and 87% of the liars – results superior to most traditional interview techniques.

The main reason drawing seems to be effective in identifying liars is that they have less time to work out the details. Someone who is telling the truth already has a visual image of where they were and what happened (even if it’s not perfect, which of course it never is), but liars have to manufacture the details. It’s easier to concoct something verbally than to first visualize and then create it on paper.

ResearchBlogging.org
Vrij, A., Leal, S., Mann, S., Warmelink, L., Granhag, P., & Fisher, R. (2009). Drawings as an innovative and successful lie detection tool Applied Cognitive Psychology DOI: 10.1002/acp.1627

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17 Comments

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17 responses to “If You Want to Catch a Liar, Make Him Draw

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  3. Or, the person could have read this study and simply be misleading the detectives altogether. Of course, the simpler answer is that they’re no good at art or vice versa. If they interrogate an art major, the detectives might want to be prepared for that eventuality too. If they really want to catch a liar, they should use other more tried and true methods… like a polygraph test.

  4. commorancy – thanks for the comment, but I have to disagree. Whether or not the subjects were good at art is really irrelevant. They could have drawn stick figures and the same dynamic would apply: either they included the agent in the picture, or they didn’t. The agent could have been a stick figure or a smiley face or a smudge with dots for eyes, doesn’t matter. If it was or was not in the picture mattered.

  5. So I am assuming that the drawing concept came before the handwriting analysis.

  6. Luke

    commorancy,
    Polygraph tests are definitely tried and definitely not true. The fact that they’re still used even when they can be tossed out as evidence in court is a joke.

  7. Jamaal

    Polygraph tests are garbage. They might want to use the tried and true methods of evidence-based critical thinking.

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  9. njoyinghim4vr

    This was fascinating! As someone who has studied Psychology in grad school I have to say the numbers are really impressive. It was shocking to learn how unreliable eyewitness testimony was and how difficult it is to not sway a witness as they are being interviewed. The concept makes sense, we are visual creatures but not necessarily great artists…I am intrigued and this tends to support the idea of art therapy for adults in cases where determining the truth is important. Thanks for sharing!

  10. I am a cop and I understand the idea behind this, I can hardly draw a straight line, let alone add any detail to things I see every day. If it works, great, but as with anything new I have my doubts. I would love to try this out though. http://vertexhorizons.wordpress.com

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  12. This seems interesting but the overall effect seems small. It certainly isn’t a magic bullet to distinguish liars and truth tellers.

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