How to detect lies: microexpressions and the science of truth - non verbal communication

Everyone lies. From social "white lies" to serious deceptions in business or relationships. The ability to distinguish truth from falsehood is a superpower that, contrary to popular belief, does not depend on intuition but on scientific observation. Forget myths like "if they look to the right they're lying." Modern lie detection is based on baseline incongruence, cognitive load and, above all, facial microexpressions discovered by researchers like Paul Ekman.

In this article we delve into the most fascinating module of our Nonverbal Communication Course: credibility analysis and deception detection.

1. Microexpressions: The Face Never Lies

Microexpressions are involuntary facial movements that last less than one-fifth of a second. They are a leak of genuine emotion that the rational brain cannot control in time. Even if the person tries to put on a "poker face," their limbic system betrays them for an instant.

The 7 Universal Emotions: Regardless of culture or language, all humans express these 7 emotions the same way:

• Surprise: Raised and curved eyebrows, very wide eyes, jaw drops. It is the briefest expression. If someone maintains a surprised face for more than a second, they are probably faking it.
• Fear: Raised and drawn-together eyebrows (forming a straight line), tense upper eyelids, lips stretched horizontally.
• Disgust: Wrinkled nose and raised upper lip. It's key to detect if someone really dislikes a proposal even if they say yes.
• Anger: Lowered and drawn-together eyebrows, piercing gaze, pressed lips.
• Happiness: The genuine smile (Duchenne) involves the orbicular muscles around the eyes (crow’s feet). If only the mouth moves, it’s a social or fake smile.
• Sadness: Inner angles of the eyebrows raised, corners of the mouth turned down. It’s the hardest expression to fake.
• Contempt: The only asymmetrical expression. One corner of the lip lifts slightly. It’s a sign of moral superiority and a devastating predictor in relationships and negotiations.

2. Incongruence and Baseline

To detect a lie, you first need to know how that person behaves when they tell the truth. This is called establishing the "Baseline".

How to establish the Baseline: At the start of a conversation (or interview), ask simple, non-threatening questions ("How's the traffic?", "Where are you from?"). Observe their blink rate, posture, habitual gestures and tone of voice. That is their normality.

Looking for the "Hotspots": When you ask the difficult questions ("Why did you leave your last job?", "Are you seeing someone else?"), look for deviations from that baseline. Do they start blinking faster? Do they suddenly touch their face? Does their voice become higher pitched? A single indicator does not prove lying, but a cluster of changes indicates a high cognitive or emotional load: something is being concealed.

3. Common Warning Signs (Red Flags)

Although there is no "Pinocchio nose," there are behaviors statistically associated with deception:

Body Freeze: The liar tends to become rigid. Lying requires a lot of mental effort, and the brain "shuts down" bodily movement to concentrate on constructing the story. If someone who normally gestures a lot suddenly freezes, be alert.

Linguistic Distancing: Liars avoid using "I" or "me." They use impersonal language to dissociate themselves from the lie. They also tend to give too many irrelevant details to try to make the story believable ("over-justification").

The Object Barrier: Placing objects (a cup, a laptop, a bag) between oneself and the interlocutor right after an uncomfortable question is an unconscious attempt at protection.

4. The Effect of Cognitive Load

Lying is hard. The brain has to invent a story, make sure it is coherent, control the body and monitor whether the other person believes it. All at once.

How to use it to your advantage: If you suspect someone is lying, increase their cognitive load. Ask them to tell the story backwards (in reverse chronological order) or ask unexpected sensory-detail questions ("What music was playing?", "What color was the wall?"). The liar will struggle enormously to maintain the fabricated structure under this extra pressure, and verbal and nonverbal leaks will begin to appear.

Detecting lies is not magic, it is mindful attention. In our advanced course, we use slow-motion videos to train your eye in detecting microexpressions until it becomes second nature.