9.Watch for micro expressions.
观察微表情
The true measure of a person’s emotions will quickly flash across their face at the beginning of a conversation. It could be a half smile that lasts for five seconds or a worried look that lasts the same amount of time. These micro expressions are sometimes noticed by people subconsciously and they tend to know right away that a person is lying, although they do not know how they know this. A lot of people tend to feel a “gut instinct” about something such as a person who is lying, and this is usually as a result of seeing a micro-expression during a conversation. The micro expression is quick but if you watch for it you can see it.