Trying to interrupt what the other person is saying, opening one's mouth frequently as if to speak. Eyes flicking about, blank stares, flipping through literature without really reading it, looking at others in the office, looking at the person's body or clothing. Avoiding moving closer, even when something is handed to the person, is strongly negative. Negative facial expressions. These include shaking head, eyes narrowed, scowling, frowning.
Body language is more meaningful when several expressions take place at the same time.
For example, the combination of leaning forward, nodding, and smiling is a strong indication of agreement and openness. Most meaningful is a matched set of gestures that agree with what the person is saying. As a rule of thumb, individual body positions or movements are frequently meaningless. Some faces form a smile or a frown more naturally than a neutral expression. What is meaningful, however, is a transition from one body position to another.