I don't know that it is as prevalent these days but as recently as the 60s there were a considerable number who would describe themselves as "Upper middle class", and look down on the middle classes (and, worse, the lower middle classes) as the sort of people who would put three plaster flying ducks in a row.

The middle classes were ghastly people like the social climber Hyacinth Bucket (pronounced bouquet). They probably went to grammar school (cringe) and could not speak properly.

The Upper middle classes had gone to public school, preferably for more than one generation. Often they were professionals (lawyer, doctor, dentist, military, civil service, vicar, usually not priest because the Upper middle classes were usually not Roman Catholic (apart from those who went to Downside). Some were Jewish. There were some who had displayed an unfortunate taste for art or music at university and become rather bohemian, like Nick Drake. There were very few non-English, usually only those from an equivalent or better foreign milieu who had been educated at Oxford (for some reason usually not Cambridge) who spoke impeccable Queen's English.

Above them were the county set and minor gentry. They (or close relatives) had inherited landholdings.

Above them were the aristocracy - the holders of inherited titles (or the close relatives of such).

"Society" - as in "The Society pages" was different again and did include foreigners a significant proportion of whom or whose families were Greek and owned ships, and eminent families who had colonised the colonies but now had funny accents like South African or Australian.

Apart from the lower middle class, they would all have been horrifed or offended baldly to have been called "Middle Class".