Welcome BrianB, you and I tend to cut against the common grain I think. Every New Yorker I've ever met in New York City has been a great individual, polite, willing to go the extra mile to show off their town, never took me, a rube, for a cent. Same with Chigagoans, approached the right way they've got pride in their city to light up the midway. Maybe its the luck of the draw, never coming up against anyone who wants to take us down, but probably it does come down to interpersonal skills and giving people enough leeway to decide to treat you like a human being. Anyway, I'd rather believe in my own fictional Jedi mind tricks rather than some innate hatred in other human beings, neither is exactly true.
I will confess to a different feeling of brotherly love in right field of Yankee Stadium versus Wrigley Field - in one I was glad not to be wearing a Mariners cap, and kept my cheering down a bit while the visitors cleaned up on the Yankees. After all it doesn't happen every day, or half the days. But the fans can't get over the Jay Buhner trade in right field, ever.