PLOSOne publication based on research project of SHS course
© 2015 EPFL
Within the SHS program at EPFL, students perform their own research project in the course « Experimental Cognitive Psychology I & II ». Christine Mohr (Institute of Psychology, University of Lausanne) and Mathieu Arminjon (University of Geneva, Agalma Foundation) coordinate this course. They are pleased to announce the publication of a research article based on experiments performed by Amer Chamseddine, Vladimir Kopta, and Aleksandar Paunović. The study investigated cognitive mechanisms that people apply when making lying judgements on faces.
Lying detection has always been of interest to psychologists for its evolutionary implications. For instance, some evolutionary theories assume that humans are equipped with an inbuilt capacity to quickly and efficiently decide whether somebody is lying or not. Some studies on face expressions supported this assumption while others found that humans are bad in correctly detecting whether another person is lying or not.
In the current study, we hypothesized that previous results showed inconsistent lying decision tendencies, because lying detection is based on two cognitive systems: the first one is fast and automatic, while the second one is controlled and slow. When people are lying, they surely do not want this to be spotted. Thus, when facial expressions are contradictory (displaying lying and non-lying information) an observer might be most uncertain about whether a person is lying or not. This uncertainty might indicate that the observer is switching from an automatic-fast system to a controlled-slow system.
To test this hypothesis, the three EPFL students created artificial faces to which they added an increasing amount of lying (e.g. looking down) and non-lying cues (e.g. smile). Participants decided for each face whether this person was lying or not. Results showed that participants were most uncertain and slow when faces contained very few lying cues (irrespective of the number of non-lying cues). This observation suggests that different cognitive mechanisms come into play when people perform lying judgements on faces that differ in complexity.
This interdisciplinary study would not have been possible without the continuous and dedicated commitment of the three SHS students Amer Chamseddine, Vladimir Kopta, and Aleksandar Paunović.
The full article, published in PLOSOne, is freely available at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0136418