What the Face Reveals

1. FACS: A Microscopic View of Facial Expression

This book is the first to bring together research that examines facial behavior directly.

Anatomical Precision. The Facial Action Coding System (FACS) is a comprehensive, anatomically based system for measuring all visually discernible facial movement. It breaks down facial expressions into 44 unique action units (AUs), each corresponding to specific muscle contractions. This level of detail allows researchers to move beyond subjective interpretations and to objectively quantify facial behavior.

Beyond Emotion. FACS is not limited to measuring only emotion-related movements. It can be used to study a wide range of facial behaviors, including those related to deception, pain, and social interaction. This makes it a versatile tool for exploring the complexities of human behavior.

A Foundation for Research. FACS provides a standardized method for measuring facial behavior, enabling researchers to compare findings across different studies and laboratories. It also allows for the discovery of new patterns of facial movement that might be relevant to various psychological variables.

2. Spontaneous vs. Deliberate: The Face Tells a Tale

Virtually all previous research focused on the inferences observers draw from depicted or enacted facial expressions; it did not really examine what was going on in the face itself.

Two Pathways. Spontaneous facial expressions, driven by genuine emotion, originate in subcortical motor centers, while deliberate expressions, such as poses or attempts to mask emotion, are controlled by the motor strip of the neocortex. This difference in neural pathways leads to distinct characteristics in the timing and morphology of facial actions.

Temporal Differences. Deliberate expressions often show more irregularity in timing than spontaneous expressions. Spontaneous expressions tend to have a smoother onset and offset, while deliberate expressions may appear jerky or abrupt. This difference in timing can be a key indicator of whether an expression is genuine or feigned.

Morphological Differences. Deliberate expressions may lack the subtle muscle contractions that are characteristic of spontaneous expressions. For example, the Duchenne smile, a genuine smile of enjoyment, involves the contraction of the orbicularis oculi muscle around the eyes, which is often absent in posed or masking smiles.

3. The Elusive Smile: Deception and Enjoyment

Smiles when lying.

Not All Smiles Are Created Equal. The smile, often considered a universal sign of happiness, can be used to mask negative emotions or to deceive others. The key to distinguishing genuine smiles from deceptive ones lies in the presence or absence of the orbicularis oculi muscle contraction, which creates wrinkles around the eyes.

The Duchenne Smile. The Duchenne smile, named after the French anatomist who first described it, is characterized by the simultaneous contraction of the zygomatic major muscle (which raises the lip corners) and the orbicularis oculi muscle (which raises the cheeks and creates wrinkles around the eyes). This type of smile is associated with genuine enjoyment.

Smiles When Lying. When people attempt to deceive others, they may use smiles to appear friendly or trustworthy. However, these smiles often lack the orbicularis oculi contraction and may have other subtle differences in timing or symmetry. These differences can be detected through careful analysis of facial behavior.

4. Infant Faces: A Window to Innate Emotion

Do infants show facial expressions of emotion, and if so, to what extent does this imply an innate versus a culturally learned expressive system?

Innate Discrimination. Newborn infants can discriminate among different taste stimuli, such as sweet, sour, salty, and bitter, and show distinct facial responses to each. This suggests that some sensory skills and affective responses are not learned but are innate.

Universal Expressions. Infants across cultures show similar facial expressions in response to certain stimuli, such as arm restraint. This suggests that some basic emotional expressions are universal and may be biologically based.

Developmental Changes. While some basic emotional expressions may be present from birth, the way these expressions are used and interpreted changes over time. For example, infants may initially show a generalized negative response to aversive stimuli, but with development, they may begin to show more differentiated expressions of anger, fear, or sadness.

5. Automated Facial Analysis: The Future of Measurement

Can facial measurement be automated?

Efficiency and Objectivity. Automated facial analysis systems offer the potential to overcome the limitations of manual coding, which is time-consuming, expensive, and subject to human error. These systems can provide objective, quantitative measures of facial behavior with high levels of accuracy and reliability.

Feature Point Tracking. One approach to automated facial analysis involves tracking the movement of specific feature points on the face, such as the corners of the mouth, eyes, and eyebrows. This method can provide detailed information about the timing and intensity of facial actions.

Machine Learning. Another approach uses machine learning techniques, such as neural networks, to recognize patterns of facial movement. These systems can be trained to identify specific action units or combinations of action units, and they can be applied to both posed and spontaneous facial behavior.

6. Psychopathology and the Face: A Diagnostic Tool

Can certain facial behavior changes indicate one’s personality or, for that matter, mark the presence of psychopathology?

Diagnostic Markers. Facial expression variables can be useful in discriminating among diagnostic groups, such as schizophrenics, depressives, and manics. Certain facial behaviors may be associated with specific psychopathologies, providing potential diagnostic markers.

Blunted Affect. Schizophrenics often show blunted affect, which is characterized by a reduction in the range and intensity of emotional expressions. This blunting may be more pronounced for certain types of emotions, such as positive emotions.

Dissociation. In some psychopathologies, there may be a dissociation between the subjective experience of emotion and its outward expression. For example, schizophrenics may report feeling emotions but show little or no facial expression.

7. The Heart of the Matter: Emotion and Coronary Health

Linkages Between Facial Expressions of Anger and Transient Myocardial Ischemia in Men with Coronary Artery Disease.

Anger and the Heart. Facial expressions of anger are linked to transient myocardial ischemia, a condition in which there is a reduction in the oxygen supply to the heart muscle. This finding suggests that anger may have a direct impact on coronary function.

Nonenjoyment Smiles. Nonenjoyment smiles, which lack the orbicularis oculi contraction, are also associated with ischemia. This suggests that even seemingly positive facial expressions may have negative health consequences when they are not genuine.

Beyond Hostility. While hostility, a trait associated with anger, is a risk factor for heart disease, facial expressions of anger may be a more direct indicator of transient coronary dysfunction. This suggests that the state of anger, not just the trait of hostility, is important to consider.

8. Craving and the Face: Unveiling Addiction

Effects of Smoking Opportunity on Cue-Elicited Urge: A Facial Coding Analysis.

The Urge to Smoke. Facial expressions can reveal the affective nature of the urge or craving to smoke a cigarette. When smokers anticipate a brief wait before smoking, they show evidence of positive affect in their faces. When they anticipate a longer wait, negative affective expressions ensue.

Craving as a Positive Experience. At briefer durations, the craving for a cigarette may be a positive experience, which may explain why it is so difficult to quit smoking. This finding sheds light on the nature of addiction and has implications for smoking cessation interventions.

Contextual Factors. The analysis of facial behavior can help identify contextual factors that influence craving. For example, the anticipation of a longer wait before smoking may trigger negative emotions, which may make it more difficult to resist the urge to smoke.

9. Coherence: Expression and Experience in Sync

Coherence between expressive and experiential systems in emotion.

Congruence. Facial expression and emotional experience are more often congruent than not, and this congruence is mediated by the intensity of the emotional event. When people feel an emotion strongly, their facial expression is more likely to reflect that emotion.

Moment-by-Moment Analysis. Facial expression and emotional experience vary together on an intra-individual basis. This means that the changes in facial expression and emotional experience are not only correlated across individuals but also within individuals over time.

Intensity Matters. The coherence between expression and experience is stronger during more intense emotional events. This suggests that the link between these two systems is not always present but is more likely to occur when the emotion is strong.

10. Asymmetry: Brain, Face, and Emotion

The asymmetry of facial actions is inconsistent with models of hemispheric specialization.

Challenging Theories. Facial expressions of emotion are not biased or asymmetrical in ways predicted by theories of hemispheric specialization for emotion-relevant processing. The expressive intricacies of deliberate versus spontaneous facial expressions of emotion are not consistent with some neuropsychological theories of hemispheric specialization.

No Simple Formula. The relationship between brain activity and facial expression is complex and not reducible to simplistic formulas. While the right hemisphere may play a role in emotional processing, it does not necessarily follow that facial expressions of emotion will be stronger on the left side of the face.

Individual Variation. Asymmetry in facial expressions is not consistent across individuals. Some people may show stronger facial actions on the left side of the face, while others may show stronger actions on the right side. This suggests that individual differences in brain organization may play a role in facial asymmetry.

11. The Social Dance: Interaction and Facial Expression

In what ways do the facial behavior patterns of one person in a conversation influence those of another?

Interpersonal Regulation. Facial expressions play a crucial role in regulating social interactions. The facial behavior of one person in a conversation can influence the facial behavior of another, creating a dynamic interplay of emotional signals.

Therapeutic Context. In psychotherapeutic interactions, the sharing of positive affect, as indicated by facial expressions, facilitates a productive therapeutic context. The therapist's facial expressions can influence the client's emotional state and vice versa.

Micro-Sequences. Prototypical affective microsequences (PAMS) are short sequences of interaction in which common strategies to cope with affective conflict situations can be observed. These sequences are characterized by specific patterns of facial behavior and can be used to understand the dynamics of interpersonal relationships.

12. The Power of Context: Emotion and Situation

What We Have Learned by Measuring the Face.

Context Matters. The meaning of a facial expression is not fixed but depends on the context in which it occurs. For example, a smile may have different meanings in a social interaction than in a solitary situation.

Display Rules. Cultural norms, or display rules, influence when it is appropriate to express an emotion and to whom one can reveal one's feelings. These rules can account for observable cultural differences in emotion expression.

Beyond the Face. Facial expressions are not the only source of information about emotion. Other factors, such as body language, vocal tone, and speech content, also play a role in the communication of emotion. A comprehensive understanding of emotion requires considering all of these factors.

Last updated: February 3, 2025