Is "Speech" Better Than "Eyes" for Detecting Lies? Psychology Re-examines How to Identify "Suspicious People"

"If it's true, you should be able to look me in the eye and talk."

When you can't agree with someone's explanation, you might feel like saying something like this. But is it true if they make eye contact and a lie if they look away? Conversely, if someone speaks calmly and logically, should you trust them?

The German publication WELT featured Michaela Pfundmaier, an expert in testimonial psychology, questioning the so-called "signs of lying" such as blinking, gaze, and restless movements.

Considering this theme from related research, what emerges is the difficulty of identifying a "liar's face." Even when shifting focus from the face to the content of the conversation, there is no foolproof method of judgment.

Is there scientific evidence for "looking left means lying"?

Some people might have heard the explanation that you can judge whether someone is recalling a memory or fabricating a story based on the direction of their gaze.

A study published in the academic journal PLOS ONE in 2012 examined claims derived from Neuro-Linguistic Programming (NLP) that associate specific eye movements with lying. The results of three studies did not support these claims.

What can be concluded from this is that you cannot determine truth or falsehood just by looking at someone's gaze. This doesn't mean all research on eye movements is meaningless; rather, the expected support for a simple rule like "right or left" was not found.

In everyday conversations, we should pause before attributing meaning to eye movements. Are they thinking of an answer, feeling pressured by the questioner, or distracted by something else? It might not be possible to distinguish based on appearance alone.

The focus is on "unexpected events" included in the story

In research that uses words as clues, elements called "complications" in a story have been examined. Broadly, this refers to circumstances that complicate the development of events.

Consider the following two explanations, both created for understanding.

"I met a friend at a store, had a meal, and went home."

"We arranged to meet at the store, but my friend was at a different entrance, so we contacted each other and met up."

The latter includes circumstances where things did not go as planned. Whether or not such elements are included in a narrative is the subject of research.

A 2018 study compared 27 people recounting actual trips with 26 people fabricating travel stories. In explanations given after hearing a concrete narrative example, those telling the truth included a higher proportion of such elements. However, this difference was observed only after hearing the example.

This does not mean there is a rule that "real stories always have detours." The conditions under which the story was elicited also affected the results.

"Neat explanations" and "correct explanations" are not the same

In this field of study, it has been suggested that people who lie try to keep their stories simple, because creating complex narratives requires more thought and effort to maintain the explanation.

However, you should not reverse this to think "because the story is concise, it's a lie."

When reporting in meetings, we sometimes omit detailed backgrounds and start with the conclusion. Even at home, the length of the explanation might change depending on whether you're asked "Tell me everything that happened" or "What was the outcome?"

Even for the same person's experience, the way it is narrated changes depending on what the listener is seeking. Truthfulness should not be easily compressed into a single measure along with the eloquence or amount of information in the explanation.

On social media, the anxiety of being "the one doubted"

A 2023 post in the Reddit science community introducing related research received comments expressing concern about oversimplifying judgment methods. The following is a summary of the post content and does not represent a survey of overall public opinion.

One user explained that they become nervous worrying whether they will be believed even when telling the truth. Another user expressed concern that, being poor at speaking and having vague memories, they might be considered a liar by such standards.

On the other hand, there was a counterargument that some people add many details to lies to make others believe them.

These personal experiences alone cannot negate research findings. However, they provide material for considering what happens when headlines introducing research turn into everyday rules like "You can spot it this way."

"Because the explanation is short, something is being hidden."
"Because the explanation is long, it's making excuses."

If either way of narrating can be used as grounds for suspicion, the other person has no way to dispel doubt. This becomes more about aligning with preconceived impressions than verifying truth.

Even "what research has revealed" has conditions

On the research side, the ease of verification is also questioned.

A review published online in 2025 examined 30 publications dealing with "complications." While there was some consistency in definitions and a numerical possibility of reproducing results, it pointed out a lack of necessary classification procedures and the publication of anonymized raw data for verification.

This is not a conclusion that "everything was wrong." It is a matter of whether external researchers can access the necessary materials to verify the results.

There is a gap between promising clues and universally applicable judgment methods. If this gap is overlooked, the articles introducing the research themselves may give readers undue confidence.

For practical use, focus on verifying facts rather than "judging" the other person

Here is a consideration of everyday situations based on the research.

For example, if there is a discrepancy in a work report, rather than pressing with "Why are you looking away?" it is more effective to organize what was confirmed and when to get closer to the root of the problem.

"Please tell me in order, as far as you remember."
"Is that something you saw yourself, or something you heard from someone else?"
"Can we check the dates together with the records?"

These questions are not to guess the person's inner thoughts from their expression but to break down the explanation into verifiable information.

It is also important not to treat slips of the tongue, vague memories, misunderstandings, and intentional falsehoods the same from the start. In conversations where corrections are not allowed, it becomes difficult to rectify inaccurate explanations.

Trusting someone and verifying the content of their story can coexist. Conversely, having strong doubts does not necessarily enhance the accuracy of verification.

What we should question is not just whether the other person "looks like a liar," but also the listener's stance on what basis they are making that judgment.

Source URL

1. WELT
   https://www.welt.de/wissenschaft/plus6aacfcb4708e760b5e062c75/psychologie-wer-luegt-vermeidet-diese-aspekte-aus-angst-unglaubwuerdig-zu-wirken.html

2. Wiseman et al. (2012), PLOS ONE "The Eyes Don’t Have It: Lie Detection and Neuro-Linguistic Programming": Original paper examining NLP claims about lie detection based on gaze direction.
   https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0040259

3. Vrij et al. (2018) "Within-subjects verbal lie detection measures: A comparison between total detail and proportion of complications": Study comparing information volume and proportion of complications using travel narratives.
   https://doi.org/10.1111/lcrp.12126

4. Neequaye "Reproducibility in lie detection research: A case study of the cue called complications": Online publication in 2025, published in 2026. Review examining verifiability and data availability across 30 publications.
   https://doi.org/10.1111/lcrp.12315

5. Reddit・r/science: Public discussion on the introduction of related research in 2023. Refers to posts about the relationship between "detailed explanations" and truthfulness, and the anxiety of being doubted. Not a direct response to the WELT article.
   https://www.reddit.com/r/science/comments/128h4v0/figuring_out_a_lie_forget_body_language_just/