Not long ago, I visited a Trader Joe’s in Boston’s Back Bay. As I went to pay for my goods, I found a seemingly endless line for the cash registers. Well over 40 people were waiting to check out. It was “rush hour,” so perhaps I had no right to be surprised. But startled I was — and not because of the line. It was fascinating to see that everyone was in a good mood. There was no complaining. In fact, everyone seemed to think the situation was just fine. These people were chatting happily with one another while they awaited their turn, even though they were a bunch of strangers! And strangers in New England, a region not known for its denizens’ patience, hospitality, and/or predilection for idle chitchat. Where was all this good cheer coming from?