• A common Technique for detecting lies is watching what direction a person’s eyes shift when they are thinking of the answer to a question. If you are facing the person, and they look to the right, they are remembering something, if they look to the left, they are creating something in their mind.
I’ve used this as a game. Someone would say 3 sentences. Only one would be true. I could tell which was a lie if they looked to the left. I find that for very few people this actually works upwards of 90% of the time, while for a lot of people I met, it doesn’t work at all, especially when they just stare into my eyes when I ask a question. But I do think it’s helpful in lie detection to pay attention to what the potential liar is paying attention to.
• A person who is lying to you will avoid making eye contact. This is only sometimes true. A lot of people lie while maintaining direct eye contact. However I feel this is actually more true in Japan, when someone tells me an obvious lie, often avoid eye contact with me.
Emotional Gestures & Contradiction
• Emotional gestures and words are not coordinated. Such as someone saying “ I love that movie!” / giving a compliment, / saying anything that should have more emotional investment then smiling after making that statement rather then at the same time the statement is made.
• Fake smiles. I really hate fake smiles, and I see them all the time in Japan. A fake smile only uses muscles around the mouth. Whereas a real smile involves movements of the whole face. The jaw/cheek, eyes, forehead are all involved.
• I’ve noticed that people lying often stutter, even a little when they are saying the lie. Also, their grammar may be off and they might speak softly. However this is also a general sign of nervousness characteristic of shy people regardless of if they are lying or not.
Those are just some common body language references. People may also put some sort of barrier between themselves and the person they are lying too, like a book, cup or their hands. But basically, I look for behavior that differs from a person’s normal way of interacting with people. You can also keep in mind what a person values and thus would like to protect by lying. Such as suggested by a university of Massachusetts study that found women are more likely to lie to protect someone’s feelings, while men are more likely to lie to defend or improve their own image.