I was watching one of those "follow your soul" programs on TV (OK, it wasn't *that* bad, even though Norman Vincent Peale was on it.) Anyway, one of the speakers claimed that people who were giving and spent their lives in service to others lived longer than others, and that there were studies to prove it.
This is exactly the opposite of what I remember seeing; it's my memory that researchers found that curmudgeonly, selfish, outspoken people lived longer. Thus, the stereotype of an old man yelling "You kids get off my lawn!" He's still around, while the nice old lady who baked everyone cookies is presumably not.
Anybody know more? A web search turned up a lot of information about long-lived dog breeds.