True lies : who can learn to tell?

Abstract

Non-verbal cues can provide behavioural signals of deception to observers. Microexpressions are facial cues that indicate the presence of an emotion being concealed by a deceiver. During deception, deceivers often attempt to conceal an emotion by masking it with an expression of another emotion such as a smile. Despite this, micro-expressions may be leaked during masking to reveal the hidden emotion. Nonetheless, research has shown that the majority of people recognize the occurrence of deception no better than could be expected by chance. Micro-expression detection training has been suggested to improve micro-expression detection skill that is linked to improved deception detection. The present study examined the effectiveness of the Micro-expression Training Tool (METT) in improving students’ and police officers’ skills in detecting masking smiles. The visual attention of trainees and untrained controls was measured via eye tracking during a pre and post test masking smile detection task. Results revealed that training did not have an effect on task performance, but practice did alter task performance. Following practice, all groups showed better detection of true smiles but not for masking smile detection. Participants’ abilities to identify masked emotions and location of microexpressions on the face varied as a function of the emotion present, as did their attention to the relevant regions of the face that contained a micro-expression. These results suggest that traditional micro-expression training is not sufficient to train observers in masking smile detection. This result has significant implications for future training protocols and many professional groups, as masking smiles are often employed during attempts at deception.