Provincialism is an unsophisticated, small-town way of life. City dwellers commonly accuse those who live in the country of narrow-minded provincialism.
Talking about someone's provincialism is fairly derogatory and critical — the word implies a view of the world that is very small and cut off from the wider world. You're most likely to be seen as having this trait if you're from the suburbs or a rural area. Many people start life with a bit of provincialism, becoming more sophisticated and knowledgable about the world as they grow older and gain experience.