Being judgmental is probably the single biggest obstacle to effective communication, especially in work teams. This is not to say that you cannot make a judgment or express an opinion about what the other is saying. To be a truly effective, however, make sure that you do not let your own opinions, feelings, reactions, or preconceptions prevent people from delivering their entire message. Be open and receptive until they have finished. Evaluate and judge after they have spoken, not before. Then make sure you understand exactly what they said and what they mean. Once they have delivered their message, it is your turn to deliver yours.
Let’s say that a small group of subordinates comes in to tell you that a project has fallen completely behind schedule. The deadline cannot be met. If you become angry, condescending, or exasperated—and show it—before they finish explaining the problem, you will put them on the defensive, and could make them angry and uncooperative. You risk getting them to work harder to salvage the project. They might go through the motions, but they will probably not work at the top efficiency.
The same can happen when you assume you know what people are going to say, and cut them off before they can finish saying it. It is rude, and you risk alienating them as well as being wrong. If you interrupt, belittle, or react before people finish talking, you destroy their trust in you, and seriously damage your chance of effectively communicating with them. You also seriously limit your opportunity to receive potentially valuable information.