Can You Tell when Someone is Lying

Question

How can you tell when someone is lying to you? What makes it obvious that someone is lying? Maybe, I'm naive but I can't honestly tell if someone is lying unless they have told me the story before and they changed it.

Answer 1

Body language is the number one tell.  They won't make eye contact, they fidget.  Usually you look up in the air when you are making something up.  When you are lying your pupils get bigger.  Your heart rate speeds up so if you notice them start breaking a little heavier or excess energy by tapping (especially if they aren't normally fidgety).  If it's something they could easily prove (like by showing you their cell phone or something) and they get really defensive and say things like I don't know how I could prove it to you.

Turn it around on you.  For example if you ask a simple question like Where were you last night?  And they turn it around defensively to Do I have to report in to you?  Why do you always act like my mother?  They try to change the topic to a fight over your behavior instead of answering what was a very simple question.

There are some good books on the subject written by the FBI guys that do this stuff for a living.  I love them.

However that won't help if someone is good lying--like telling you No one saw that or You are too good for him.  B/c if they aren't feeling guilty about it a lot of the signs won't be there.