How Do You Detect a Person Who is Lying?

Well, heard this interesting piece of info from the session earlier today... Is the scene from CSI or NCIS questioning a suspect true? Or simply based on the intuition?


Here's what I found from this interesting site.

Myths on lying:

1. People don't actually fidget and look away when they're lying. Even some police forces still have this in the manual even though it's just plain wrong.
2. Even classic highly researched signs of lying are not that good. Less blinking, more pauses in talking, vocal tension, pupil dilation, chin raise and nervousness don't consistently (across different people) mean someone is lying.
3. It may be particularly difficult to detect lies in close friends or partners as we have come to trust them and don't expect them to lie to us.

How to detect lie?

1. Individual differences are key. Some people's natural behaviour looks honest while others' natural behaviour doesn't. This won't tell you whether each is lying. E.g. introverts or socially nervous people tend to look as though they're lying when they're not. The way to do it is using comparisons. It's possible to spot falsehoods when they are compared with truthful statements.
2. Micro-expressions. Good lie detectors can pick up on tiny facial movements that give away lies. The problem is that they're 'micro' so they're difficult to detect.
3. Vocal inflection can be vital. There's evidence it's easier to detect lies just from the voice. The eyes are relatively easy to control and it can be better if we can't see them.
4. Rely on intuition. People may be better at detecting lies with their intuition. Implicit or broadly unconscious processes can be more effective than conscious directed thought.
5. Lying is hard work. Lying can place high cognitive demands on an individual - putting more pressure on a suspected liar can help with detection.

So yeah, the next time you spot someone acting fidgety when talking to you... Maybe he/she is just nervous about talking to you... Or maybe he/she is rushing for time? Or simply he/she needs to go to the loo ;p