Hello MrPedantic,
Yes, that's right. Sometimes other type of conflicts are carried out in the disguise of disputes on linguistic or stylistic matters. At least in 18c, though!

I like your expression:

people identify themselves so strongly with the dialect they happen to speak

... quite penetrating ...!

There're other reasons, too. I'll try to explain them, if there's appropriate occation.

Hello, MrPedantic,

I haven't read S. Pinker yet, to tell the truth. Seems the reference in that site is to his The Language Instinct. I found the following phrase and it surprised me a little bit.

the idea that language is a biological adaptation

It's tough for me to swallow this statement whole now. It's quite new for me!

I've heard that in the middle ages [grammar] was [glamour]. Only educated(?) people knew that ...
How about this?

Actually "glamour" comes from "grammar". It was originally a corrupted form of a Scot word for "grammar" and it also meant "magic". Probably, to most of common people of pre-modern times, skills of writing sentences looked something magical. It would be the reason "glamour" and "spelling" connote "magic" also.

paco

Yes, I imagine you are full of glamour because you are studying "English glamour" so hard.

Throughout Medieval Age, "grammar" meant "study of Latin literature". A phrase "English grammar" was first used by Ben Johnson in 1600 as the title of his English grammar book.

OED says:
"In early English use "grammar" meant only Latin grammar, as Latin was the only language that was taught grammatically. In the 16th c. there are some traces of a perception that the word might have an extended application to other languages; but it was not before the 17th c. that it became so completely a generic term that there was any need to speak explicitly of "Latin grammar". Ben Jonson's book, written c1600, was app. the first to treat of ‘English grammar’ under that name.
As above defined, "grammar" is a body of statements of fact—a ‘science’; but a large portion of it may be viewed as consisting of rules for practice, and so as forming an "art". The old-fashioned definition of grammar as "the art of speaking and writing a language correctly" is from the modern point of view in one respect too narrow, because it applies only to a portion of this branch of study; in another respect, it is too wide, and was so even from the older point of view, because many questions of "correctness" in language were recognized as outside the province of grammar: e.g. the use of a word in a wrong sense, or a bad pronunciation or spelling, would not have been called "a grammatical mistake". At the same time, it was and is customary, on grounds of convenience, for books professedly treating of grammar to include more or less information on points not strictly belonging to the subject."

Enjoy a glamorous Monday!

paco