CONFIRMATION BIAS. This is how a person can be when they are regarding another person. It could be another culture, or nation, or whatever, but in this case we are interested in when it is a person regarding another person.

The general idea is that they have a bias, and they wish to only confirm this to themselves, and the way they do this is to see only what they want to see. So if they wanted to see someone as a loser they will only notice their failures but not their successes,

The reason why they do this is because they find it difficult to be wrong, or maybe they are selfish and so in order to get what they want which they would otherwise not be entitled to they alter reality to fit them that they can get and serve their selfish needs. It could be other reason, like avoiding an obligation, or avoiding guilt, etc.

It is a bit like PROJECTION, it is altering reality to suit their self. These people are going to be awkward characters, very unreasonable, trying anything to have their way, going to any lengths, makebelieving fantasy is reality, etc. They would lie and cheat, and even believe it. They will twist anything to get what suits them and avoid what doesn't suit them.

It is a problem with them, they are maldeveloped. If you get involved with such a character you can have all kinds of problems. They can be very clever, they can seem normal, sane, etc. They can be believed, which is potentially very dangerous.