Might seem obvious, but most people aren’t aware enough to recognize their own nervous habits and then consciously fight to conceal them.
Yes, we know, this feels like it’s out of a bad mob movie, but it’s still one of most common signs of raised stress levels.
3. Failure To Make Eye Contact
A very common indicator of deceit or guilt.
4. Dilated Pupils
And it they can manage to look you in the eye, check for this sign of high stress levels.
5. Elongated Pauses
If someone has to lie on the spot, they’ll usually take an extra second or two longer than normal to collect their thoughts. Listen for multiple pauses.
6. Rise In Vocal Pitch
Another sign of increased stress levels the studies have found to be more common in liars than truth tellers.
7. Will Protest Too Much
In normal conversation, if your companion uses qualifiers like ‘to be honest’ or ‘I swear’ it implies that they don’t expect to be believed or trusted. Implication of lie is higher.
Congratulations, you are now officially an expert!
And will never ever ever (probably) fall for a lie ever again. SOURCE