Q: Why should you never ask a man if he is from Yorkshire?
A: Because if he is he will have already told you and if he isn't you don't want to embarrass him with the question.
There's a UC San Diego student doing lab experience in a lab near me. He's a bit of a fashion victim and today was wearing tweed and a flat hat. I had the biggest desire to run up to him and shout:
ey up lad, where't though whippet
In general though I'd say Northerners are far more likely to tell you where they come from (and be prouder of it )
He might well have been from Yorkshire... you do know that Yorkshire Airlines fly to San Diego
http://www.youtube.com/watch?v=Rm6VC5gdaFA