Part 3/8:
The examiner discusses how physiological signals are merely indicators and not definitive proof of deception. A person trying to conceal the truth may show signs like making less eye contact, nodding to affirm falsehoods, or exhibiting microexpressions—brief flashes of emotion that betray inner feelings. One common telltale sign includes scratching or rubbing the back of the head, which he interprets as a subconscious signal of feeling threatened or trying to buy time.
He underlines that effective lie detection involves analyzing a cluster of behaviors and reactions, rather than relying solely on one cue. Timing is crucial; observing when a person exhibits a certain behavior can make a significant difference in interpretation.