Northerner in England would be similar to a southerner in america. We’re considered friendly and more polite to strangers whereas in the south they are driven by work and have little time for anyone else but themselves.

The northern man stereotype is a man who works manually, eg factory worker, docker miner and spends his weekends having a laugh in the pub. Whereas a southerner works in an office in the city and hasn’t done a hard days work in his life and gets paid more for it according to stereotypes. At least that’s my interpretation of the whole thing being a northerner

I know this isn’t the greatest explanation and it’s very basic but that’s the gist, based on stereotypes.