We want truth. No matter if the lies are unharm or for good intention, we want to found it out. BBC’s h2g2 section has a good guide on detecting lies. One could detect through simple signs physically or from the tone and speech – and of course one would use machine and even chemicals:
The type of lie, and whether it is in keeping with the liar’s character, dictates how apparent the signs of lying are. Occasionally they are extremely obvious, especially when the liar is feeling guilty.
Obvious signs include:
* Over denial – Repeating protests of innocence.
* Stuttering – Stumbling over words without natural fluency.
* Hand Wringing – Fiddling, rubbing, picking and playing with the fingers and hands while talking.
* Eye Contact – Unwillingness to make or never breaking it.
However, the majority of people intending to tell a lie fabricate their story long beforehand and become comfortable with it, and so rarely get caught out so easily. Equally, many of the signs indicated may also simply be signs of nerves due to shyness or discomfort with a new situation.
Detecting Lies – [BBC - h2g2]