As a result, when I left Scotland I made a conscious decision to call myself English rather than British thereafter and that's still how I fill out forms etc. I can't remember who wrote the essay, nor the full detail, but its grand sweep was something like "if we don't have our hatred of the English to bind us, then what? Given that we seem to hate each other." In essence, that chimed with my experience of a basically sectarian Glasgow.
I've been around Britain this summer. In Sunderland I was fully expecting some Geordie-bashing. None occurred. In Swansea I was treated like royalty by everyone bar the Mecure hotel chain. But on the course I ran in Edinburgh there was a rant from a lovely woman about how the "East and West up here hate each other". Such a nation coming out of a referendum split 50/50 is surely a worry either way....?