Those with superiority/inferiority issues will often take certain traits about themselves or about another person and use that as evidence and proof of OVERALL superiority or inferiority.
In other words, they'll take something like being very good at mathematics as evidence of general superiority over another. Only those who are also very good at mathematics, either at their level or above, will probably be considered "equals" or "peers", regardless of their abilities in other areas.
Many people will use physical traits as evidence of superiority or inferiority; any physical trait will do. And they'll often "trade" one for another in order to maintain their own superiority.
For example, Sheila sees herself as superior to Joyce, because she's taller than Joyce. But when Simone shows up and towers over Sheila, she is forced to either concede that Simone is superior to her because Simone is taller (using her own measuring stick), OR she will hold on to her "superiority" by TRADING or CHANGING the measuring stick. So Sheila is still superior to Joyce (in her mind) because she's taller than Joyce, but Simone's height "doesn't count" because... .... her skin and hair is lighter than Sheila's... so therefore Sheila is still superior (in her mind) to both Joyce and Simone.
When a superior/inferior minded person comes across another who "beats them" in too many of their own measurements, they may either try to "take them down", or they may concede to the other person's "superiority". But it will probably not occur to them that the measuring sticks they insist on using could be wrong or unnecessary, or that they don't actually need to use them at all.