As a Northerner living in the South, I will tell you that Northerners are painfully conscious of how they treat and are perceived by others and try to minimize their impact on other people. Southern Hospitality is mostly fake and really more about trying to size you up and figure out details about your life (but yes, in some areas people will go way out of their way to help you out with stuff).
New Orleans residents are outliers. They are far and away the friendliest people I've met anywhere in the US, but at the same time it's a tourist economy and everyone seems to have a hustle. Much love for New Orleans.