Facial Expression: The Ability to Distinguish Between Enjoyment and Non-enjoyment Smiles by Spencer Coffman

Abstract

The smile is a universally recognized facial expression that is generally associated with happiness. However, this may not always be the case and discerning the difference is surprisingly difficult. Enjoyment smiles involve the involuntary contraction of the orbicularis oculi, which lifts the cheeks and narrows the eyes, and the zygomaticus major, which raises the lip corners. Non-enjoyment smiles only use the zygomaticus major (Frank & Ekman, 1993). In the current study participants watched Facial Action Coding System (FACS) coded videos of smiles and were asked whether they believed the smile was real or fake. Tobii X120 eye-tracking software was used to determine the most focused upon facial muscle when interpreting the smiles. It was estimated that the majority of participants would perform at a level slightly above chance, achieve an average of 60% accuracy, and pay most attention to the zygomaticus major (Ekman & Friesen, 1982; Frank, Ekman & Friesen, 1993). Results indicated that the majority of the participants performed significantly above chance, with an average 65% accuracy, and focused on the orbicularis oculi. These findings suggest that the ability to detect smiles is increasing and people tend to look at the eyes rather than the mouth during a smile.