As said above.
What are some words to describe someone who always thinks that everyone else is acting as if they are superior.
An example of the type of person I'm talking about would be Frank Costanza from the TV show Seinfeld.
I first read this as "What's a synonym for someone with an inferiority complex?" The link below has 34 synonyms and none of them describe Frank Costanza. I think that's because Frank comes across as strong and aggressive, whereas people with inferiority complexes are seen as more passive.
Frank seems to have a "superiority complex" (possibly due to an inferiority complex). I bet there's a word for his type in Yiddish.
How about: lofty, condescending, or disdainful? Also Frank exhibits "hauteur".
inferiority complex noun [ C ]
a feeling that you are not as good, as intelligent, as attractive, etc. as other people:
- He's always had an inferiority complex about his height.
feeling extremely nervous and worried because you believe that other people do not like you or are trying to harm you:
- He started feeling paranoid and was convinced his boss was going to fire him.
I am not familiar with the television show. It is interesting to me that your title does not match well with your question.
"Someone who thinks everyone is supercilious" is someone who thinks others are haughty, disdainful, or contemptuous. It is not just that others are acting as if they were superior, but that these others are actively demeaning or contemning those around them.
"Supercilious" means to raise the eyebrows. That is the facial expression that accompanies the attitude of "You are saying something stupid."
from Dictionary.com: "Supercilious" adjective 1. haughtily disdainful or contemptuous, as a person or a facial expression.