I have recently started reading Pies and Prejudice by Stuart Marconi which is a book which talks about the North South divide from the perspective of a Northerner. Not so much on the socio-economic differences or geography, but on the defining characteristics of the people.
The book is well written and funny as you might expect, but I can't help, but think that the comparison is being made with a straw man. The first chapter talks about his experiences of the South and I was struck by a definition of the South that encompasses: London, East Anglia, The Midlands, The Home Counties and The West Country (He defines the North as starting at Crewe station).
I feel fairly well qualified to talk about this as I am an East Anglian with a Lancastrian mother who has lived in Suffolk, Birmingham and London and has spent quite a bit of time in Wigan, Liverpool and Manchester where I have family and friends.
I want to avoid making too many generalisations, but in my experience people from the North will tend to self identify with the concept of being a Northerner whilst I don't know many people who would describe themselves as a Southerner in any meaningful sense not only because it tends to be used as a term of mild abuse, but because its impossible to give it any meaning other than "Not a Northerner". I would always consider myself an East Anglian over any other geographical description not least because though Ipswich is fairly far South the North Norfolk cost is as far north as Stoke on Trent.
When I first moved to Birmingham I found it a very alien place to be. The accent could be hard to understand and the cultural reference points and sense of humour were different. It's much the same if I go to Cornwall for a holiday. I certainly don't sound the same as these people or have any more in common with them any more than if I spend a day in Wigan or Sheffield.
In terms of the traits that I could identify the differences between the people from Wigan and the people from Bristol that I've met aren't really that pronounced. Accent is the obvious one which amongst the middle classes doesn't tend to be all that different anyway (the tell tale Baaarth/Bath excepted).
The one that has been pointed out to me on several occasions is that people randomly talk to you at bus stops, but I have been just as aware of that in Birmingham or the East end as I have been in Sheffield or Manchester though I do conform true to type as if I don't have a specific question to ask I hate being engaged in conversation by strangers (Though I think that reflects badly on me not my place of birth)
I must say it has never been something that has any bearing on my life, but I'm interested to know how others feel on the subject.
I shall leave you with this anecdote from freshers week at Birmingham University upon being introduced to a new person who was from Macclesfield (I should add this is one of the only times something like this has ever happened to me).
Me: Hello I'm Nick
Them: That's a funny accent, where are you from?
Me: Suffolk
Them: Ah a Southerner, eh I expect you don't want to speak to a Northern Monkey like me then?
Me: Erm
Them: cos that's the problem with Southerners isn't it... not very friendly you don't give people like me a chance, you just form opinions about us from the off, I don't know how you get by really. Now with a Northerner they would give you a chance you would be chatting away like old mates by now, everyone is just so friendly, but Southerners are just such miserable bastards you don't have a chance
Me: You're not really giving me a chance now.
Them: Typical (Storms off)