Just read the survey by Oswald and Blanchflower on the happiness literature. Something that surprised me was that there was very little discussion of the effects of culture on how people respond to surveys. It was mentioned but I thought it would be more important than this. I notice that as someone originally from England that I am much less willing to award high scores on surveys of say hotels or movies or whatever than Americans are and probably this also translates into how I would report on my happiness compared to people from some other cultures. Or is this not really important?
The paper does mention eating fruits and vegetables as being important for well-being. This is investigated in more depth in another of the authors' papers. I wonder if that helps explain why everyone seems to be so miserable in Eastern Europe in all these surveys? :)