Next time when someone says something about someone else, check your mental process. What do you normally do? Do you simply listen and defer from judging the person about whom something is being said or make some judgements based on what's being said. Chances are very high you judge the other person just based on what's being said. This is more true if the person who is saying about the other person is someone known to you. Shame on us, if we do this routinely and unconsciously.
You have just conducted a kangaroo court session.
It's commonsense that we should listen to all points of views before forming an opinion about someone or something. It is even ok not judge at all. But, nothing can be worse than judging someone without getting all sides of the story. I would rather be neutral if I am not able to judge rather judge in a rush.
All of us make this mistake from time to time. One of the best ways to avoid this is by putting ourselves in the position of the other person on whom we are forming an opinion or judging. How do we feel if someone hears something about us from somebody else and passes a judgement on us that's not fair to us. Don't we feel bad? More often you ask this, more you will be able to defer judging people.
More and more relationships, personal and professional, get seriously affected because we rush to judge. We rush to form opinions. We want to brand people. We want to stereotype them. It's natural but if we really want to advance, this is one anti-pattern that we must overcome. If we do not learn not judge others, we are going to be judged as poor judge of people and go down the drain in no time.
Remember even if you own a gold mine, you need other people to mine the gold for you. We all need other people when we try to accomplish even simple tasks. If we have judged others with prejudice, chances are we are going to miss out on some good people who could have become our good personal friends or good professional acquaintances.