Observational Measurement: Face Features

Observational Measurement of the Face

A variety of coding systems were developed in the 1970s and 1980s for use in the study of facial expression. The most popular of these systems is the Facial Action Coding System (FACS). While the FACS is primarily descriptive, it can be used to draw inferences about the expression of emotion or deception. FACS relies on observation of over 40 distinct Action Units (AUs), which are unique muscle movements in the face. AUs for the face include various movements of the brow, eyes, cheeks, nose, lips, and chin. Each AU refers to a specific, finite movement of a facial muscle. For example, an inner brow raise, outer brow raise, and brow lower are considered distinct AUs. Facial behavior can also be coded for the intensity of the movement, including ratings for (a) trace movement, (b) slight movement, (c) marked or pronounced movement, (d) severe or extreme movement, and (e) maximum movement. Combinations of AUs can indicate deceptive intent or particular emotional expressions.

Facial Features as Indicators of Deception

Deceptive intent is often inferred through observation of leakage cues, or nonverbal behaviors that convey the anxiety or guilt of the deceiver. Facial features that have been observed as reliable indicators of deception include more blinking and lip presses/adaptors and fewer head movements and less facial expressiveness generally. Some micro-expressions, fleeting expressions of suppressed emotion, have been observed as indicators of deception. Most micro-expressions are visible in a person’s face for less than half a second and are most easily observed when reviewing recordings of communication in slow motion. Micro expressions related to guilt and stress are often associated with perceptions of deceptive intent.

Facial Features in Communication of Emotion

Emotions presented facially take place because of sequences of muscle movements and contractions that change in specific patterns. [Page 1108]Paying close attention to these patterns of contraction as well as what is not being contracted can help narrow down the emotion being conveyed facially. Areas that require close observation include eyelids, eyebrows, cheeks, lips, forehead, nose, jaw, and chin. When emotion is conveyed facially, generally it is done quickly. This rapid conveying of emotion is what makes closely monitoring the face important.

When observing emotions, they can be considered separate entities (e.g., surprise, fear, anger, disgust, sadness, and happiness) or emotions can be viewed as part of a family or cluster of emotional expressions (e.g., slight anger, frustration, fury, or blending of emotions, such as angry-afraid). When understanding emotions as separate entities, there are unique characteristics that set a particular emotion apart from the other distinct emotions. The emotions of anger and sadness are offered here as examples.

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