I've never been to Minnesota, and they don't seem to be different from people anywhere else in North America from what I've noticed. Most North Americans are pretty loud, extroverted, and social in general, (almost to a degree that would be somewhat offensive to people from certain other world cultures,) as that's what's deemed favorable by the culture, and a lot of naturally introverted people feel a lot of social pressure to act extroverted in order to get along with everyone else. I have read though that people in the Great Lakes area are mostly descended from Scandinavians and other Northern Europeans, and I've heard pretty much most of those same characteristics used to describe people from Northern Europe also (as opposed to Mediterraneans who are generally thought of as being a lot louder, more extroverted, and overtly social), so maybe they retained some of those cultural elements while still getting louder and more Americanized like most other people here.