I see what you guys are saying. So a rich Pureblood would be taught manners and such, and that's what the question originally asks. Because you've got...I suppose you can say lower upper class, middle upper class, and upper upper class, and those are the levels of society. Lower upper class, we know for a fact the the Weasleys will be there. Then you've got the middle upper class, which encompasses a wider range of Pureblood familes, and then the select few upper upper class families like the Blacks, Lestranges, Malfoys, Rosiers....And they learn how to behave according to their status.
...I forgot what I was going to say, but I wanted to point this out:
I've not read this essay, but I've always thought that Neville would be in the middle upper class, his family being fairly wealthy. One reason is that when I read in PS/SS Neville's story about being dropped from a balcony by his great uncle, I saw that he had a large family. The other is reading about Neville's grandmother's attire. She wears such frivolous clothing and I'm quite sure that the material is all real. I can't imagine an average person wearing something like that. Also, Neville's Gran has this air of authority and haughtiness, but perhaps its simply her character. How much is a remembrall, also? It must be a bit expensive, as it's got a fancy bit of magic in it.there's an essay on the Lexicon that puts Neville in the same social class as Ron. The only two incredibly wealthy students in Harry's year are Draco Malfoy and Justin Finch-Fletchley.
And though Ernie does not lord it over other students, I think he had a bit of pomp.
Just throwing that out there.