A person who has cognitive bias will show different signs. For example, let us say that you have cognitive biases; then, you will typically show all or a few of the following signs:

Assuming you are always correct: You will not approve of other people’s opinions or decisions for assuming that you are the one who is right – all the time, and in all the cases.

Blaming others when things go wrong: You will always find a way to blame others if things do not go as planned. You will never question yourself – even if you are the one actually responsible for that.

Assuming you know more than you really do: You will not entertain different options or opinions in cases of any such necessity because you think that you already know everything you should know. You simply deny the fact that nobody knows everything; rather, people must welcome different ideas and new information to become more knowledgeable.

Believing that everyone thinks like you: You show a tendency to ignore what others feel, or want to express because you think that what you are proposing is ‘universal’; you think that all other around you are thinking in the same and in the same way as you are doing. You do not want to give it a thought that this cannot be true.

Only noticing things that confirm your beliefs: You say something, or do something, and look for ways to legitimate it. There are many other ways that can prove you wrong; but you pick only those information or statement that reassures your ideas.

Attributing other people’s success to luck: When you succeed, you describe it as a result of extensive merit or hard work – even if this is not entirely true; but, when another person succeeds, you do not want to recognize their merit or labor, you are not willing to give them any credit for that; rather, you try to explain and establish it as their luck or just coincidences.

This is not a complete list of signs in regard to cognitive biases; there can be other signs depending on variables like the person, situation, bias type and so on.

To be honest, everybody has biases. That is a common phenomenon. We will not be able to overcome all the biases that we have. It is not possible to bring the level of bias down to zero. But what we can do is to look into ourselves, analyze our behavior critically, be honest and admit our biases, and then try our best bring the level as close to zero as possible.