When it comes to relationships, understanding whether someone is being truthful about their intentions is crucial.

Some experts argue that nonverbal signs of lying aren't reliable and paying attention to behavior may not help you detect a lie. "A truth teller also might be nervous or emotional about whatever ...

In her new book "The Body Language of Liars," Glass reveals eight signs to look for to know if someone is lying ... high probability that he or she is not telling you the truth," writes Glass.