This Personality By State post at GetListy discusses recent research from the University of Cambridge, which ranked aspects of personality by state.  North Dakota came in number one for extrovertedness and again for agreeableness.  The state came in last for openness.

It’s exactly what I see.  The people of North Dakota may not like change (they treasure traditions of hard work, family closeness, creativity and innovation), but they are warm, friendly and easy to get along with.

(And I personally like the fact that there are some things they’re not open to–it helps keep ND a safe and happy place to live.)