How to Spot a Traitor: What Body Language Can and Can't Tell You

You've watched it happen at the round table. Someone is accused. Their face flushes, a hand goes to the neck, the voice climbs half a note, and they start explaining too much. The room decides. They're banished, they turn round to reveal, and they're Faithful.

Meanwhile the actual Traitor sits two seats down, calm, warm, nodding along. Nobody looks twice.

I read body language for a living, and I watch The Celebrity Traitors every week. The show is the best demonstration on British television of how people misread each other. Here is what body language can tell a Faithful, what it can't, and why the castle keeps getting it wrong.

The bad news first: nobody can spot a liar by looking

The largest study of lie detection, a 2006 meta-analysis by Charles Bond and Bella DePaulo covering 206 studies, found people tell truth from lies 54% of the time. Guessing gets you 50%.

The detail matters more than the average. Truthful statements were judged correctly 61% of the time. Lies were caught only 47% of the time. We aren't just bad at it. We lean towards believing. Researchers call it truth bias, and it's the Traitors' best friend: a calm, likeable player gets the benefit of the doubt in every room.

A 2003 review by DePaulo and colleagues looked at 158 behaviours people associate with lying. Most had little or no link to it. There is no single tell. Anyone who says they can spot a Traitor from one gesture is selling something.

So "how to spot a Traitor" has an honest answer: you can't, not from body language alone. What you can do is stop making the mistake that banishes Faithfuls, and start noticing the moments worth a question.

Why the round table banishes the wrong people

Being accused of lying on national television is stressful whether you're lying or not. Stress shows on the body in the same way for both.

• Flushing, swallowing, a dry mouth: the nervous system reacting to threat. Accusation is a threat.
• Touching the neck, face or collarbone: a pacifying behaviour, the body soothing itself under pressure.
• Over-explaining: someone who feels they're not being believed keeps talking until they are.

Paul Ekman named this the Othello error: reading the distress of an innocent person who fears they won't be believed as a sign of guilt. Othello saw Desdemona's fear and took it for proof.

The round table is built to produce the Othello error. The Faithful who is accused shows every "tell" the group is hunting for. The Traitor, who has rehearsed being accused since the first night, often shows fewer. Stress signals tell you someone is uncomfortable. They don't tell you why.

What body language can actually tell you

Body language is good at one thing: change. It tells you that something shifted, and when. It doesn't tell you what the shift means. The method we teach has four parts, and they work as well in a castle as in a job interview:

1. Baseline. How does this person sit, talk and hold their hands when nothing is at stake? Breakfast, the missions, the drive in. A fidgety person fidgeting tells you nothing.
2. Change. What moves away from that baseline, and at exactly which moment? The timing is the information.
3. Cluster. One cue is noise. Three changes at the same moment are worth noticing.
4. Context, then a question. Is there an innocent reason? You can't know until you ask, so ask an open question and watch the first second of the reply.

Five cues worth watching at the round table

None of these means "Traitor". Each one means "something changed here, ask about it".

1. The lips disappear. When the lips press together until they almost vanish, the person is holding something back: a reaction, a word, an emotion. Joe Navarro calls this lip compression, and it's one of the more reliable signs of stress. What it doesn't prove: what they're holding back. It could be a secret. It could be anger at being accused.

2. The face stays, the body leaves. Watch the feet and the torso, not the face. People manage their faces well. They rarely manage their feet. When someone keeps a friendly face towards the accuser but the torso turns away, or the feet point at the door, the body is distancing itself from the conversation. Navarro calls this ventral denial. What it doesn't prove: guilt. Discomfort with the person accusing them fits just as well.

3. The smile that arrives on time and leaves late. A felt smile tightens the muscles around the eyes, and it fades naturally. A social smile involves only the mouth, and it's often held a beat too long, as if switched on and forgotten. Watch the smile when someone else is accused. What it doesn't prove: a polite smile is just politeness. It matters only if it changes at a telling moment.

4. Stillness when their name comes up. The first response to threat isn't fight or flight. It's freeze. A player who has been moving freely and goes completely still when a name is said, theirs or an ally's, has reacted to something. What it doesn't prove: Faithfuls freeze too. The question is which name triggered it.

5. Relief in the wrong place. Traitors know who the other Traitors are. Faithfuls don't. So watch the vote reveal and the banishment. A flicker of relief — the shoulders dropping, a breath out, the face softening — when a fellow Traitor survives the vote, or when suspicion lands on a known Faithful, is the closest thing the show offers to an informative cue. The player knows something the room doesn't. What it doesn't prove: anything on its own. Relief that your friend is safe looks exactly the same.

The "tells" that mean nothing

The castle relies on these every week. The research doesn't support any of them.

• Avoiding eye contact. Liars don't reliably look away. Many hold eye contact more, because they know people check for it. Watch the video: what 206 studies say about eye contact and lying.
• Crossed arms. Usually comfort, cold or a chair without armrests. Not defensiveness, and not deceit.
• Fidgeting. A baseline trait for many people, and a stress response for everyone.
• Blushing. Embarrassment and anger both produce it. Being accused on camera produces plenty of both.
• "Too calm." Some people go quiet under pressure. A calm Faithful gets suspected as often as a calm Traitor.

How a Faithful should actually play it

If I were in the castle, I'd use body language to choose questions, not verdicts:

• Learn baselines early. The first few days, before anyone is accused, are the only clean data you'll get.
• Watch reactions to other people's accusations. A player under direct attack is stressed whatever they are. A player watching someone else get attacked has less reason to react, which makes a reaction more interesting.
• Watch the reveal, not the speech. Rehearsed words come out clean. The unscripted seconds after a vote are harder to manage.
• Ask, don't announce. An open question ("what made you vote for her?") gets a reply you can compare with their baseline. An accusation just gets stress.
• Count the cues. One means nothing. A cluster, at a meaningful moment, is worth a question at breakfast.

Why this matters outside the castle

The same mistake costs real money and real careers away from the show. Interviewers reject nervous candidates for "lying". Shop staff stop anxious customers who have stolen nothing; I wrote about telling nervous from stealing for Loss Prevention Magazine. Teams trust the warm colleague and second-guess the awkward one.

Reading people well means swapping "is this person lying?" for a better question: "what just changed, and what should I ask about it?" That's what our Body Language Foundations course teaches, and it's what we train hospitality, retail, security and HR teams to do. For a quick test of your own reading, try the free body language quiz.

This week at the round table

Updated after every episode while The Celebrity Traitors is on air.

Episode 3 (8 October). Two reads from Thursday's round tables: what Hannah Fry's long blink does and doesn't show, and why a live TV presenter is the hardest Traitor to read.

Every weekly read, Strictly included, is collected on our press page.

Frequently asked questions

Can body language tell you who the Traitor is?
No, not on its own. Lie detection runs at about 54%, barely above chance. Body language shows you moments of change worth asking about. It doesn't give you verdicts.

Why do Faithfuls get banished so often?
Because being accused is stressful, and stress looks the same whether you're lying or not. The group reads the innocent player's distress as guilt, which Paul Ekman called the Othello error.

What's the most useful thing to watch in The Traitors?
Reactions when someone else is under suspicion, and the unscripted seconds after a vote is revealed. They're harder to rehearse than a round-table speech.

Image: BBC/Studio Lambert