5 Signs of Lying from an Ex-FBI Agent: Which of Them Work — a Polygraph Examiner’s Comment

At the end of September 2026 a headline went round Ukrainian news sites: “Exposing a liar is easy: ex-FBI agent names 5 typical signs”. UNIAN published it on 24 September, and konkurent.ua reprinted it the next day. Both retell a piece from the American outlet YourTango dated 23 September.

The author is Jack Schafer, a former FBI special agent and behavioural analyst, now a professor at Western Illinois University. But the text is not new: YourTango republished his column “5 Things Liars Commonly Say”, which appeared in Psychology Today back in November 2016. So the “news” is almost ten years old, and it is the opinion of an experienced interrogator, not the result of a study.

The five signs Schafer names

All five are phrases, not gestures.

1. “That’s about it.” The word “about” supposedly shows that the person has not told everything.
2. “You can’t prove that.” An honest person, according to Schafer, does not think about proof, because there is nothing to prove.
3. “Why would I do that?” Answering a question with a question buys time to come up with a story.
4. “Are you accusing me?” A counter-attack that puts the person asking on the defensive.
5. “I don’t remember doing that.” An appeal to memory instead of a straight “no”.

Which of them the research supports

The largest review on the subject is the meta-analysis by Bella DePaulo and colleagues, “Cues to Deception” (2003): 158 cues, 1,338 estimates from 120 samples. The authors’ main conclusion: many behaviours are either not linked to lying at all or linked only weakly. Now point by point.

“About”. The idea that insincere people are less forthcoming was partly confirmed in the review: on average their accounts contain fewer details. But the effect is small, and the “cautious” words themselves, such as “probably” or “about”, showed no reliable link with lying. Plenty of people always talk like that.

“You can’t prove it”. I found no separate data on this phrase in the review. Schafer’s logic is clear, yet a person who is unjustly accused and angry answers in exactly the same way.

A question for a question. This one is about buying time. In the meta-analysis, a delay before answering on the whole barely distinguished lies from truth. A difference appeared only when people had to lie without preparation. If the person was expecting the conversation, there will be no pause.

“Are you accusing me?” I found no data on this particular reaction either. Indignation is an ordinary response to an accusation, whether it is true or not.

“I don’t remember”. The most interesting point. According to DePaulo, in accounts of an event the admission “I don’t remember that” occurred more often among those who were telling the truth: insincere people avoid anything that looks like a weak spot in their story. This rests on only five estimates, and it concerns an account rather than the denial of an act, so it does not refute Schafer directly. But there are no grounds for counting “I don’t remember” among the signs of lying either.

Schafer himself admits as much in the 2016 original: “There’s no one verbal cue that accurately predicts deception.” In the reprints and retellings this caveat has all but disappeared, while “is easy” has appeared in the headline.

How well people detect lies

In 2006 Charles Bond and Bella DePaulo pooled the results of 206 papers in which 24,483 people tried to tell truth from lies without instruments or training. The average result was 54% correct judgements. Lies were recognised in 47% of cases, truths in 61%. A coin toss gives 50%.

What this means for you

If you suspect a partner, an employee or a relative, a phrase from this list is a reason to ask a follow-up question, and nothing more. An accusation built on “he answered a question with a question” is just as likely to hit an innocent person.

If you are the one under suspicion, know that indignation, pauses and “I don’t remember” prove nothing. I wrote about the common signs in the article “How to Tell if Someone Is Lying”, where I also warned that they give no guarantee. The meta-analysis shows how serious that warning is: even eye contact, regarded as a classic sign, has almost no link with lying in the pooled data.

A practitioner’s comment. People often come to me who have already been “convicted” at home or at work on the strength of a phrase or a look. During the test both those who are telling the truth and those who are not get nervous, so I draw no conclusions from behaviour. The conclusion comes from the recording of reactions to specific questions.

Practical advice

• Compare the person with themselves. What matters is not the phrase but a change in their usual manner on one particular topic.
• Ask open questions and ask for details that can be checked: the time, the place, who was nearby.
• Ask them to recount the events in reverse order. In experiments by Aldert Vrij and colleagues (2008), such an account produced more noticeable differences between truthful and insincere participants, and police officers judged them more accurately. This is a technique for a conversation, not a test.
• Check words against facts: messages, documents, camera footage. Schafer also calls this the best method.
• If the matter is serious and there are no facts, agree on an instrumental test. A polygraph does not guess from words; it records physiological reactions, and its accuracy is 85–89% according to the American Polygraph Association’s meta-analysis (2011). I work in person in Lviv; from another city or country you can take the VerifEye online test on a smartphone. Testing is possible only with voluntary written consent, and no method gives 100%. The cost is on the prices page.

Questions and answers

Can you detect a lie from a single phrase?

No. Research knows of no phrase or gesture that reliably distinguishes a lie from the truth. Individual cues have a weak effect, and only on average across a group, not for a specific person.

Do investigators and agents detect lies better than other people?

Interrogation experience helps in asking questions and noticing contradictions in the facts. But the average accuracy of judging “by eye” in studies is about 54%, so professionals too rely on evidence rather than impressions.

How does an instrumental test differ from observation?

An observer interprets words and behaviour, and their own suspicions influence that. An instrument records the body’s reactions to each question, and the conclusion is drawn according to scoring rules. Errors are possible here too, but their rate is known and considerably lower.