I overheard Japanese people talking about what school to put their kids in, and they kept talking about what places are 民度低い, then the discussion switched to whether most fat people are 民度低い or not. I did not even know the term applied to people as well, but it seems that it does indeed.
While the meaning slowly becomes obvious to people who hear it all the time, how would you explain it to a kid who has never heard the term?
Objectively, on what criteria do people usually tell whether a place or person is 民度低い ?
I am aware that different people use different criteria, but I am interested in knowing what are the most often-used criteria.