Can two simple questions expose contradictions in a story? Learn how strategic follow-up questions can reveal inconsistencies and help you evaluate whether someone’s account is reliable.
To Catch a Liar, Ask These Two Questions: A Psychological Technique for Spotting Contradictions
When you suspect that someone isn’t telling you the whole truth, your first instinct may be to watch their eyes, study their body language, or look for nervous behavior.
But there is a problem with relying on those signals alone: there is no single facial expression, gesture, or eye movement that reliably proves someone is lying.
A more useful approach is to pay attention to the person’s story.
Instead of trying to “read” someone’s body, ask questions that encourage them to explain what happened in their own words. Then listen carefully for contradictions, missing details, changes in the sequence of events, or explanations that don’t fit together.
Here are two questions that can be surprisingly revealing.
Question #1: “Can You Tell Me Exactly What Happened From the Beginning?”
This question sounds simple, but it encourages the person to provide a complete account rather than answering only the specific part you’re asking about.
Don’t interrupt immediately.
Let them explain.
Pay attention to the sequence of events:
- What happened first?
- What happened next?
- Who was present?
- Where did the event take place?
- What happened afterward?
The goal isn’t to catch someone making a mistake.
It’s to establish their original version of the story.
A truthful person can forget an insignificant detail, especially when an event happened a long time ago. Likewise, an honest person can become nervous when they feel accused.
So a single mistake should never automatically be treated as evidence of deception.
Question #2: “Can You Go Through That Again, Step by Step?”
This follow-up can be useful because it asks the person to reconstruct the same event rather than simply repeating a short answer.
Listen for meaningful changes.
For example, someone might initially say that they arrived at a particular location before speaking to another person. Later, when describing the same sequence again, they might place the conversation first.
One difference doesn’t prove that someone lied.
But multiple important contradictions can be worth examining.
The key is to compare the substance of the two accounts rather than focusing on tiny wording differences.
Why Repeating a Story Can Reveal Problems
When people describe an event, they don’t necessarily remember every detail perfectly.
Memory isn’t a video recording.
People can unintentionally change the order of events, forget small details, or remember something differently after being questioned.
Someone who is deliberately fabricating a story may also struggle to maintain consistency when asked to explain the same event in different ways.
That’s why the most useful clue isn’t necessarily nervousness.
It’s whether the central facts remain coherent.
Don’t Fall for the “Look Into Their Eyes” Myth
One of the most popular beliefs about deception is that liars avoid eye contact.
In reality, eye contact isn’t a reliable lie detector.
Some truthful people avoid eye contact because they’re shy, uncomfortable, anxious, or simply thinking.
Meanwhile, someone who is lying may deliberately maintain eye contact because they believe it will make them appear trustworthy.
The same problem applies to nervous gestures, touching the face, crossing the arms, or fidgeting.
These behaviors can have many explanations.
Context matters.
The Better Clue Is a Contradiction That Matters
Imagine someone tells you:
“I left work at six, went straight home, and didn’t stop anywhere.”
Later, while casually discussing the evening, they say:
“I actually stopped at the store on my way home.”
That is more meaningful than noticing that they were nervous while answering the first question.
But even then, you shouldn’t immediately conclude that they’re lying.
There could be a perfectly innocent explanation.
Maybe they forgot the stop.
Maybe they misunderstood the original question.
Maybe “went straight home” was simply an expression rather than a literal statement.
The best response is to ask another neutral question.
Try Asking “Help Me Understand That Part”
Instead of saying:
“You’re lying.”
Try:
“Help me understand how those two things fit together.”
This keeps the conversation focused on the information rather than turning it into an accusation.
The person then has an opportunity to clarify the apparent contradiction.
Sometimes the explanation will make perfect sense.
Other times, additional inconsistencies may emerge.
Pay Attention to Changes in Important Details
Not every inconsistency matters equally.
People can forget small things such as:
- The exact time
- What color someone was wearing
- The precise wording of a conversation
- Minor details about a location
More significant changes involve the basic structure of the story.
For example:
- Who was present
- Where the person was
- What happened before or after a major event
- Whether a key action occurred
- How the person supposedly learned important information
These are the details worth clarifying.
Don’t Turn Yourself Into an Interrogator
There’s another important lesson here.
Asking questions doesn’t make you a human lie detector.
If you aggressively interrogate someone, you can actually make a truthful person appear suspicious because stress and anxiety can affect how people communicate.
A better strategy is calm curiosity.
Ask.
Listen.
Clarify.
Compare.
Then consider the entire situation.
Look for Evidence Outside the Conversation
If the issue is genuinely important, don’t rely solely on someone’s behavior or storytelling ability.
Look at independent information when it’s appropriate.
For example, dates, messages, receipts, records, photographs, or statements from other people may provide information that a conversation cannot.
The strongest conclusion usually comes from multiple independent pieces of evidence, not from one psychological “trick.”