Most people call it "body language" -- the clues to the meaning that we get from gesture, facial expressions, posture -- everything that isn't spoken.Experts call it "nonverbal communication," but it means the same thing: a second source of human communication that is often more reliable to understanding what is really going on than the words themselves.        Understanding body language is important to success, whether in the business world or in our personal lives.However, most of our ideas about body language are wrong, according to modern communication research.        There is a belief that people with shifty eyes are probably lying.As Paul Ekman says, "When we asked people how they could tell if someone was lying, too much blinking and shifty eyes were the winners.But sometimes people act like that because they are shy.Liars pretend to be calm in order not to be caught.        Ekman goes on to argue against such a wrong belief.Although this kind of body language is probably an expression of nervousness, it is not always because the person is lying.Shyness can,  for example, make people shift their eyes.To understand what someone's behavior means, you have to watch them carefully.        There is also a belief that when meeting someone, the more eye contact , the better.As a result people would like to make initial contact in formal situations, like a job interview, by staring fixedly at the other human.Yet Ekman points out that most of us are comfortable with eye contact lasting a few seconds, but any eye contact that is longer than that can make us nervous. In short, you must carefully consider the speaker and the speaking environment.Experts suggest that unless you know about someone's basic communication style, you will have little hope in understanding their true feelings through body language.In other words, body language carries important but not always true messages. According to the passage, body language is   _  .
a language that is not spoken a clue to get the meaning a reflection of people's behaviors a source of human communication