Place your hand open palmed in front of your face touch your nose with your thumb whilst waggling your fingers.
That's cocking a snook.
Incidentally Bill check out any posting by Geordie Porgie for an authentic flavour of the Dialect of my own area.
I can & often do talk like that.
However (though you'd never know it from my typing) I spent a long time in postgraduate education & am capable of communicating in terms appropriate to that environment as well.
I say this not to boast but to serve as an example of the duality you suggest.
I think in time this will become a more & more commonplace occurence.
Here's hoping.