Is there a term for this mental condition?

[Reader]

Maybe it would help me figure out how to deal with it. You know sometimes when someone starts to dislike someone else, it seems that everything they do is wrong. For example, people who have an ex and suddenly everything the ex does is wrong, from the way they brush their teeth to the way they tie their shoes, even if nothing is wrong with the way said person brushes their teeth. Or if you were anti-Bush, it seemed he did everything wrong his whole presidency. I think my mother in law has developed these feelings about me, that nothing I say is remotely true or acceptable. I really think she would mount an argument that the world is flat if I said it was round. Is there a term for this vilification of someone you've decided you don't like?

[BayGirl2]

The inverse is the Halo Effect. Once you put someone on a pedestal everything they do is right/likeable.

I can't think of the name of what you are describing, but I totally know what you mean! In work situations I refer to it a "Vibing someone out". Send enough bad vibes and they will eventually leave on their own.

[justlearning]

Selective perception: http://en.wikipedia.org/wiki/Selective_perception

And here's the link to read about specific types of cognitive bias: http://en.wikipedia.org/wiki/Cognitive_bias

[cvanbrunt]

It's not a mental condition. It is a cognitive bias called confirmation bias. Basically, individuals seek out information that supports their pre-existing viewpoint or they interpret information/actions in a way supports their viewpoint. It's a very common "cognitive shortcut".

[Reader]

Thanks, that's exactly what I was looking for!