What is the Facial Action Coding System
The Facial Action Coding System, often referred to as ‘FACS’, is an internationally recognized, sophisticated research tool that precisely measures the entire spectrum of human facial expressions. FACS has elucidated the physiological presence of emotion with very high levels of reliability.
Created in the 1970s by psychologists Paul Ekman and Wallace V. Friesen, FACS provides a comprehensive taxonomy of human facial expressions. FACS remains the most widely used and acclaimed method for coding the minutest movements of the human face.
The system dissects observed expressions by determining how facial muscle contractions alter appearance. Each movement is categorized into specific Action Units (AUs), representing the contraction or relaxation of one or more muscles. All facial expressions can be decomposed into their constituent AUs and described by duration, intensity, and asymmetry. Trained experts examine patterns in the changing nature of facial appearance, including movement, changes in shape and location of the features, and the gathering, pouching, bulging and wrinkling of the skin. Understanding the coordination between action units and certain expressions illuminates the implications of human body language and non-verbal behaviour.
The 7 Universal Facial Expressions of Emotion – FACS coded
The Applications of the Facial Action Coding System
One of the most well-known applications of FACS has been to distinguish Duchenne (or “genuine”) smiles from social (or “fake”) smiles. The specificity of FACS coding reveals the anatomical elements which make it difficult to fake a Duchenne smile. While the social smile involves the contraction of a singular facial muscle, the Duchenne smile is activated by the involuntary movement of multiple muscle groupings.
The Facial Action Coding System can be used in the following ways:
- The measurement of facial behaviour and precise detection of specific emotional expressions.
- Research tool for measurement and discovery of new patterns of movements and relationships.
Benefits of Using FACS over other facial measurement systems:
- FACS is comprehensive and unbiased as a system of facial movement measurement. It can be used as a descriptive method encompassing all observable behaviour, or it can be specified to describe emotion-specific behaviour.
- FACS is unobtrusive. FACS can be applied without the subject’s awareness that their faces are being analyzed.
Research demonstrates the Facial Action Coding System has successfully:
- Discovered various patterns reliably related to deception, at 80% accuracy. (Ekman, 2001; Ekman et. al., 1988; Ekman, O’Sullivan, Friesen, & Scherer, 1991; Frank & Ekman, 1997)
- Predicted coping with traumatic loss. (Bonnano & Keltner, 1997)
- Predicted the onset and remission of depression, schizophrenia, and other psychopathology. (Ekman & Rosenberg, 1997)
- Discriminated suicidal from non-suicidal depressed patients. (Heller & Haynal, 1994)
- Predicted transient myocardial ischemia in coronary patients. (Rosenberg et al., 2001)
- Identified patterns of facial activity involved in alcohol intoxication.
How can the Facial Action Coding System work for you?
Emotional expression transcends the barriers of race, ethnicity, culture, gender, religion, and age. Decades of research have shown that humans express facial emotions in precisely the same way regardless of background. The ability to read the facial changes accompanying and predicting emotional behaviour is an indispensable component of effective communication.
Persons trained in FACS can utilize these concepts in conjunction with their expertise to benefit those who conduct interviews, interrogations, and business transactions and those involved in law enforcement, security, and the legal and healthcare systems with their expert insight and analysis.