British people, can a people be backward due to either the way their inherited accent makes them think, or the way their ancestors thought,?

Accents have nothing to do with intelligence. 

However, it is possible that some people might assume a lack of intelligence because the speaker has a regional accent.

Are you implying that accent determines intelligence? If so, then think again, it's a ridiculous idea.

I'm British and I'm struggling to understand the question.

I do wish contributors to YA would read their own writing before hitting the 'submit' button.