Personal Baseline Deviation Check
Compare behavior with the person's norm before interpreting a change
- Difficulty
- Advanced
- Time to result
- ~ongoing to results
- Steps
- 4
- Confidence
- 90%
Pearlman argues that assessing possible dishonesty starts with the individual rather than a universal gesture. He compares the approach with establishing a baseline before a lie-detector test: observe how someone normally speaks when discussing familiar, truthful material, including cadence and the amount of detail they provide. During a later conversation, look for changes from that person's own pattern instead of assuming that one movement proves anything. The method is strongest as a reason to slow down and ask another question, not as a verdict. Pearlman says regular observation can improve instinct, but the transcript does not establish accuracy rates or validate behavioral lie detection as a scientific diagnostic. High-stakes conclusions require corroborating evidence and appropriate professional processes.
Origin
Extracted from The Diary of a CEO
Core principles
- 01A single behavior has little meaning without a personal baseline
- 02Repeated observation is more useful than one encounter
- 03Look for changes in clusters rather than one universal tell
- 04Behavioral deviation is a prompt to inquire, not proof of lying
How to run it
- 1
Learn the normal pattern
Observe how the person usually speaks about ordinary facts and familiar experiences.
Pro tip Notice cadence, pauses, and typical detail without staring for isolated tells.
Watch out A short interaction is not enough to establish a reliable baseline.
- 2
Change the subject
Move to the topic you need to understand while keeping the tone non-accusatory.
Pro tip Use open questions so the person can answer in their usual way.
Watch out Stress caused by the topic or setting can resemble a deviation without indicating deception.
- 3
Compare with their norm
Look for differences in several behaviors rather than applying a generic body-language rule.
Pro tip Treat a cluster of changes as more informative than one movement.
Watch out Deviation is not proof of a lie.
- 4
Clarify and corroborate
Ask follow-up questions and check available facts before reaching a conclusion.
Pro tip Give the person room to explain why the conversation felt different.
Watch out Do not use this method as a substitute for evidence in legal, medical, employment, or safety decisions.
In the wild
Pearlman suggests noticing how often someone adds details and how they normally pace a story, then comparing those features when a later account raises concern. He presents the difference as an observation that can guide further questions, not a definitive tell.
→ The observer gains a person-specific reason to inquire further without claiming certainty from one cue.
Common mistakes
Using a universal tell
One gesture or eye movement can have many explanations and may be normal for that person.
Calling deviation proof
A change can reflect stress, fatigue, memory difficulty, or the sensitivity of the topic rather than deception.
Is it for you?
Best for
It is best for recurring relationships where enough ordinary interaction exists to learn the person's usual behavior.
Not ideal for
It is not ideal for one-off encounters, formal investigations, or decisions requiring validated forensic evidence.
From the transcript
“The best way to learn if somebody's lying to you is learning their benchmarks.”
“I try to see what do they look like when they're telling me the truth.”
From the episode
Oz Pearlman (Mentalist): This Small Mistake Makes People Dislike You! They Do This, They’re Lying!