Here is the article.  I've been in some of these but I wasn't in any of them too long.  However people are pretty much people when it's on a one to one basis.  I've been treated well in all that I've visited. 

I believe that the Quad cities have to have some of the most polite people in the world.  I swear you could run over them with a shopping cart and they would apologize.  I've been in some of the stores and either bumped into somebody or hit them with an object (pipe at Menards) and they said sorry.

Top rude cities; http://www.travelandleisure.com/articles/americas-rudest-cities