Why not both? Culture and language "progresses" (progress implies linearity– might be more accurate to say "develops" or "unfolds") through slang and in-jokes!
Check out linguist John McWorther's work on this subject: http://en.wikipedia.org/wiki/John_McWhorter
In fact it's quite interestingly parallel to how technology often starts out as toys and games (and instruments of war and pornography).
Because Shakespeare's slang and in-jokes are normal English today.
edit: The comparison to Shakespeare just seems kind of off, but beyond that, I never argued that the vernacular / slang being generated today wouldn't be used or become accepted by society at large.
>It's not progress of culture or language, simply an increase of quantity of slang
>, I never argued that the vernacular / slang being generated today wouldn't be used or become accepted by society at large.
If those 2 sentences are not contradictions, can you clarify your comment?
Isn't "accepted by society at large" part of what culture __is__ ?
A "language progress" is a movement in usage and meaning. We "progressed" from "thy" "thee" to "your" "you" etc. It doesn't mean the words starting with "y" are "better" or "clearer" (in fact, they are the opposite of the previous formal/informal distinctions.) Nevertheless, language/culture has moved on.