Microexpressions are very brief and involuntary facial expressions that appear when a person is trying to conceal or repress an emotion. They typically last from 1/25 to 1/5 of a second (much faster than normal expressions) and reveal a person’s true emotional state, even if they are attempting to hide it.

Macroexpressions- Full, longer-lasting facial expressions that usually match what someone is saying or feeling. 

Duration- ½ second to 4 second (easy to see)

Control- Often voluntary (we consciously show them to communicate emotion, such as smiling when happy

Use- Normal everyday expressions; they help in social interactions 

Example- A clear smile when happy, or a long frown when sad 

Microexpressions- very brief, involuntary facial expression that reveal hidden or repressed emotions 

Duration- 1/25 to ⅕ of a second (too fast to fake or easily notice without training)

Control- involuntary- they ‘“leak out” despite attempts to hide emotions

Use- useful in psychology, law enforcement and negotiation to detect underlying feelings

Example- A quick flash of fear before someone forces a smile

Key differences

History of micro expressions

Early observations-

The study of facial expressions goes all the way back to Charles Dawin. In 1872, he wrote The Expression Of the Emotion in Man and Animals, where he argued that our expressions are not just things we pick up from culture, they are universal and built into us. He never used the word microexpression, but his idea planted the seed for the belief that our faces that give away emotions no matter who we are or where we come from

Accidental discovery in the 1960s- 

Microexpressions were actually discovered by accident back in the 1960s by psychologists Paul Ekman and Wallace Friesen. While studying nonverbal communication they noticed something unusual, even when people tried to cover up their feelings, a tiny flash of their true emotions would slip across their face for just a split second. These flashes were so quick that most people could not control them, or even notice them, unless the video was slowed down. 

Key research developments- 

In the 1970s, Ekman and Friesen took things further by creating something called the Facial Action Coding System (FACS). This is a detailed guide that breaks down every little facial movement into tiny “action units”. With this system, psychologists could spot even the smallest muscle twitches that reveal hidden emotions like fear, anger, disgust or even sadness. Their research showed that these microexpressions are not tied to culture, they are universal. No matter where someone comes from, those split- second flashes of emotion all look the same. 

Application in Psychology and Beyond-

By the 1980s and 1990s, microexpressions started getting attention in areas like lie detection and criminal psychology, since hidden emotions often popped up when someone was being deceptive. They also became useful in therapy, counselling and emotional intelligence training, helping professionals pick up on what people might be feeling even if they were not saying it out loud. In more recent years, everything from law enforcement and intelligence work to business negotiations has made use of microexpression training. 

Modern perspective- 

Today, microexpressions are seen as a powerful tool for understanding human behaviour. They are used in psychology, law enforcement and even the corporate world, but they have also made their way into popular culture through TV shows and media. While they are not a magic lie detector, they give valuable clues about what someone is really feeling beneath the surface. Ongoing research keeps exploring how these split- second expressions can deepen our understanding of emotions, communication and even mental health. 

Why microexpressions matter and how they are used 

Microexpressions are important because they give a peek into what someone is really feeling, even when they are trying to hide it. This makes them useful in a bunch of fields where understanding emotions matters. 

1. Mental health- Therapists and counselors use microexpressions to pick up on emotions clients might not openly express, like suppressed anxiety, sadness or anger. Spotting these hidden cues can help professionals respond better, build trust and provide more effective support. For example a client may say they are “fine” but a fleeting flash of fear or sadness can tell the therapist to dig a little deeper

2. Medical training- In healthcare, microexpressions can help doctors and nurses notice subtle signs of pain, discomfort or distress in patients who may be reluctant or unable to communicate clearly. This improves patient care and helps build a stronger doctor-patient connection. 

3. Lie detection and criminal psychology- Law enforcement and intelligence agencies often train officers to spot microexpressions as part of detecting deception. One famous case involved Paul Ekman consulting for the FBI to identify hidden emotions in suspects, showing that even when people lied, tiny facial clues betrayed the truth. Another well-known example is the study of suspects in the 1995 O.J Simpton Trial, where experts analyzed expressions to understand emotional responses during questioning. 

How to spot microexpressions on faces- 

Spotting microexpressions is not easy at first, they happen in a flash, but with practice you can start noticing them, and it is actually really useful in understanding how people feel beneath the surface. 

Step 1- know the seven universal emotions

Microexpressions usually show one of the seven universal emotions:

Happiness- raised cheeks, crow’s feet around the eyes, a slight smile. 

Sadness- dropping eyelids, corner of the mouth pulled down 

Anger- eyebrows pulled together, lips pressed tight, flared nostrils 

Fear- raised eyebrows, eyes wide open, mouth slightly open

Disgust- wrinkled nose, upper lip raised , sometimes a slight sneer

Surprise- raised eyebrows, wide eyes, mouth open

Contempt- one side of the mouth raised in a subtle smirk 

Step 2- focus on the Eyes and Mouth 

The eyes are the most honest part of the face. They often reveal emotions even when the mouth is smiling or neutral. The mouth can be controlled more easily, but small twitches or shifts can leak true feelings. Watch for asymmetry, one side of the face might show emotion more clearly than the other. 

Step 3- watch for Quick Flashes

Microexpressions are super fast, often less than half a second and can be hidden under a fake smile or neutral expression. Slow-motion videos or repeated observations help beginners, but with practice you will catch them in real time. 

Step 4- look for involuntary movements 

Tiny muscle twitches, subtle eyebrow raises or lip quivers can reveal emotion. These movements often happen before someone has a chance to mask them, so they are more honest then what the person says 

Step 5- consider the context

Emotions rarely exist in isolation. Think about what the person just said or did, does their microexpressions match their words?

A mismatch between words and microexpressions often reveal hidden feelings. 

Step 6- combine facial cues with body language 

Microexpressions are just one clue. Combine them with posture, gesture and tone of voice to get a fuller picture of someone’s emotional state. 

How to tell when someone is lying

Detecting deception is not just about listening to what someone says, it is about noticing subtle physical, verbal and emotional cues. People who lie often try to mask their true feelings but the body and face can give it away. 

Watch facial expressions 

Microexpressions are huge clues. Someone might flash fear, guilt or disgust for a split second before masking it with a smile of neutral face. For example, in criminal interviews, Ekman found that suspects often show a quick fear microexpression when lying about a serious crime, even if they verbally deny it. This can be shown by their eyes opening wider or their browns lifting involuntarily for a split second as they are anxious about being caught. 

Inconsistencies between Words and Body 

People often struggle to match their words with their nonverbal behaviour. 

Examples of inconsistencies:

• Saying “i’m fine” while frowning, avoiding eye contact or clenching fists

• Nodding while verballing denying something, their body may contradict their words 

Always consider baseline behaviour, how the person normally gestures, speaks and reacts. Sudden changes can be telling.

Eye behaviour

Contrary to popular myths, liars do not always avoid eye contact, but changes in gaze can be informative

Signs to watch for:

• Rapid blinking or a sudden drop in blinking

• Shifts in gaze direction (looking up or sideways) that may indicate mental effort

For example in airport screenings, officers notice micromovements around the eyes that indicate stress, even when passengers seem calm verbally 

Signs of overcompensation include:

• Giving overly detailed accounts

• Repeating the same phrases multiple times

• Smiling too much or at unusual moments

For example Paul Ekman noted that in high-stress interviews, liars often “perform” honest through exaggerated expressions that look unnatural 

The biology of microexpressions 

Microexpression is not just psychological, it is also deeply biological. Our faces are wired to reveal emotion, even when we try to hide it 

The Brain’s Role 

Microexpressions are controlled by the amygdala, the part of the brain that processes emotions like fear, anger and disgust. When we feel a strong emotion, the amygdala sends signals to the facial muscles, often faster than our conscious mind can stop them. This is why microexpressions leak out involuntarily, even if you try to mask your feeling with a smile or neutral face.  

Facial muscles and Expression 

There are more than 40 muscles that create expressions. Tiny involuntary twitches in these muscles produce microexpressions, for example: a quick raising of the eyebrow for fear, or a slight curling of the lip for disgust. These movements are so fast and subtle that they usually go unnoticed unless you are trained to see them. 

Nervous system

Microexpressions are linked to the autonomic nervous system (ANS), which controls involuntary bodily functions. When someone feels an emotion like fear or guilt, the ANS reacts automatically, creating micro-tensions in the face before the conscious mind can override them. 

Studies by Paul Ekman and Wallace Friesen showed people across cultures (tribes in Papua New Guinea, Western societies and more) have the same microexpressions for basic emotions, proving they are biological and hard-wired and not just cultural. 

The case of Dutchess Lie (1970s- Paul Ekman) 

Background

In the 1970s, Paul Ekman was working with psychiatric patients while studying how emotions show up in the face. Ekman and his colleague Maureen O’Sullvian were analyzing videotaped interviews of depressed patients who were being evaluated to see if they were safe to leave the hospital. One particular patients became famous in Ekman’s work, she was later nicknames “mary” but Ekman referred to the incident as the Duchess lie. 

The patient interview 

The women has a history of suicidal thoughts and attempts. In her psychiatric evaluation, she spoke calmly and convincingly, insisting she was no longer suicidal and was ready to go home. Her words and tone of voice matched her story and the doctors were prepared to believe her

The Discovery

When Ekman slowed down the videotape frame by frame (using the Facial Action Coding System he was developing) he noticed something. In just 1/25 of a second, her face showed an expression of profound sadness and despair. The expression was so fast that no one in the room noticed it in real time but the camera caught it. This was a microexpression, an involuntary flash of her true emotional state breaking through her attempt to hide it. 

The outcome 

Ekman alerted the psychiatrists that the patient was still deeply suicidal despite her convincing words. Based on this finding, the doctors decided not to release her. A short time later, the patient admitted she was still planning to take her life, proving that her microexpression has revealed the truth she was trying to conceal. Ekman later reflected that this discovery may have saved her life. 

The Dutchess sadness microexpression 

This is what Ekman saw on the tape

1. The eyebrows 

• The inner corners of her eyebrows lifted and drew together slightly 

• This create a distinctive “triangle shape” above the nose

• In sadness, the brows do not just go up, they tilt toward in the middle which is very hard to fake consciously 

2. Eyes 

• The upper eyelids drooped slightly 

• The eyes looked almost "heavy" as if weighed down

• Sometimes this is described as a “wet” look or a softening in the eyes

3. Mouth 

• The corners of the mouth pulled downward, forming a brief frown 

• The lips may have quivered slightly, which is another cue of suppressed strong emotion

4. Overall expression

Taken together, the face briefly showed raw despair, lifted inner browns, heavy eyes and a downward mouth. It disappeared instantly, replaced by her calm, composed “dutchess-like” mask

Why this matters biologically 

• The amygdala (emotional centre of the brain) triggered the sadness before her conscious brain could supress it 

• The Facial Action Units (FAU’s) involved were:

• AU1 + AU4 = inner brown raise and pull together (sadness marker)

• AU15 + lip corner depressed (mouth downturned)

• These action units combine to form the universal sadness expression 

Ekman could trust this because unlike speech or body language, these micro facial cues are biologically “hard-wired” and almost impossible to fake, especially at the micro level. That is why Ekman knew these women’s true feelings were leaking through, even though her words and tone suggested otherwise. However there was one case that Ekman studied, the case of the “perfectly controlled liar” 

The case of the Perfectly Controlled liar 

In the late 1970s, Paul Ekman and his team studied a suspected fraud investigator. He had been accused of embezzling funds, but when questioned, his face looked unusually “flat”. Now normally when people lie, fleeting emotions like fear, guilt or even pleasure at “getting away with it” flash across their face but with this man nothing. No leaks. His face remained smooth, calm and neutral even when asked very personal or high-pressure questions. He pulled this off because he was an amateur stage actor in his youth and he learned how to mimic facial expressions on command. Instead of letting natural microexpressions slip, he used a masking expression. When he felt anxiety he quickly overlaid a practiced smile, and when he felt anger he replaced it with a “thoughtful” frown as if he were reflexing deeply. In other words, he did not stop emotions from happening, he covered them immediately with something else. Normally biologically the amygdala fires and leaks emotions faster than the conscious control, but he has trained his prefrontal cortex (self-control system) through acting practice to step in very fast. Instead of microexpressions of fear investigators mostly saw macroexpressions (deliberate ones). However even when liars try to take it they usually slip in other channels like timing errors (smiling too long or starting a smile too late), symmetry errors (a fake smile is often uneven with only one side of the mouth rising) and lastly eye mismatch (the mouth smiles, but the eyes stay “dead”

Microexpressions relation to Emotional Intelligence and Behavioural Science 

Another powerful reason to study microexpressions is how closely they connect to emotional intelligence (EQ). Emotional intelligence is the ability to recognize, understand and manage emotions, both your own and other people’s. When you spot microexpressions, you gain access to people’s real emotional state, not just the polished version they are trying to portray. Think about it; if you notice someone flashing sadness before forcing a smile, you can respond with more empathy, instead of missing the chance to support them. In workplaces, classrooms or relationships, this skill helps build stronger communication and trust. In fact, research shows that people with high EQ are more successful leaders, better negotiators and more effective in conflict resolution. Being able to read microexpressions feeds directly into that. On the other side, microexpressions also tie directly to behavioural science, the study of why humans act the way they do. These tiny expressions are like brief windows into the brain, revealing the hidden emotions that drive behaviour. A flicker of disgust could show up when someone is lying or trying to suppress the truth. This is why microexpression research has become so valuable in predicting human behaviour. In criminal psychology, they can signal when a suspect is concealing guilt. In business they can hint at a client's true feelings during a negotiation. And in therapy, they can help psychologists understand what a patient is feeling when words do not match emotions. 

Behavioural Science connection with Microexpressions 

Decision making under pressure 

One of the biggest insights from behavioural science is how stress and pressure change the way people make directions. In high-stake situations, like police interviews, courtroom questioning or even negotiations, microexpressions often appear because the brain is overloaded, A suspect may say they are calm but a flash of fear or anger across their face reveals the true emotional state before they can mask it. 

Deception and Cognitive Bias 

Microexpressions play directly into deceptive research. People are notoriously bad at detecting liars, we rely too much on stereotypes like “liars avoid eye contact,” which is not always true. Instead microexpressions cut through these biases, showing genuine emotions like guilt or disgust that do not match the words being spoken. Behavioral scientists like Paul Ekman have shown this gap between verbal and nonverbal signals as one of the most reliable cues to lying. 

Criminal psychology and Aggression 

In a forensic setting, microexpressions help uncover hidden hostility or suppressed aggression. A suspect might smile politely, but a flicker of contempt, a one-sided sneer can reveal a deep anger or disdain. Behavioral science uses these subtle leaks to better understand the emotional states that drive criminal behaviour, including violence or manipulative deception. 

Emotional intelligence and empathy 

On the positive side, microexpressions are not just about spotting lies, they are also about improving connection. By training to read these tiny signals, psychologists, teachers and even medical staff can build stronger empathy. For example, a therapist who noticed a split’second sadness on a client’s face can gently address emotions that may not have been verbalized yet. Behavioral science links this skill directly to higher emotional intelligence, better communication and stronger relationships. 

Now microexpression may only last a fraction of a second but the information they reveal is huge. The key takeaway? Microexpressions are not about “mind-reading” or catching someone out, they are about understanding. Whether it is helping a therapist guide a client, a doctor supporting a patient or a teacher noticing a struggling student, reading microexpressions adds a layer of empathy and insight. And as research continues, these tiny facial movements may unlock even more about how we think, feel and interact. 

“The face never lies, microexpressions are proof that our emotions always find a way to be seen.”