Bella DePaulo, a psychology professor at UC Santa Barbara, says that the motivation behind deception falls into two main categories—a person will either lie to make himself look good or to spare another person's feelings. Also, Dennis Reina, the author of "Trust and Betrayal in the Workplace" noted that men tend to lie about their jobs while women lie to be perceived as having a better social status. There are a few ways that you can spot a lie, whether it be in your personal or business life.
Ask the person a question directly, in person, and request an immediate answer. If the person pauses before responding, it is likely because he is trying to make up a lie. Do not allow him time to answer your question later, or else he will have his answer prepared.
Look at the person's body language to see if he is lying. If he fidgets, twiddles his thumbs, or looks uncomfortable, he may be deceiving you.
Keep in mind that when someone is lying or hiding something, he may get indignant. Anger at your question, even if it is not a big deal, is a indication that the person may have something to hide.
Watch the eyes. When someone looks around the room, he is searching for an answer to your question, which will most likely be an untruth. Observe whether the person is able to make and keep eye contact with you—if not, he may be telling a lie.
Listen for a change in the person's voice. If the pitch of his voice gets really high, or he starts talking in low tones so as not to be heard distinctly, he may be lying.
Be mindful of someone who tries to change the subject too quickly after a topic is raised, especially if he gives a general answer. This is a sign that the person may be hiding something.
Repeat your question to the person the next day to see if the stories match up. Look for inconsistencies in the story.
When someone is a liar (especially pathological) she knows that she is and will try her best to convince you otherwise. Phrases like "would I lie to you?" and "come on, you know I wouldn't lie" are red flags that the person is in fact lying.