Happiness and creative flow... While the first does not beget the second, I think it's safe to say that the reverse is definitely true. Being 'in the moment' of intense creativity and therefore productivity is one of the most fulfilling sensations I'm able to feel. It's within these moments that all the dots seem to connect themselves, with little forced effort from my end.
In anycase, I just read a paper detailing the findings of a study of over 800 adolescents and their levels of happiness throughout the day over a one week period. There is an attempt to correlate these moments of happiness to possible moments of activities which might induce such a 'flow'.
The results were not incredibly surprising from the researchers' point of view (the kids were happier hanging out with friends vs studying, happier on a saturday than on monday), except for one point which was taken as counterintuitive: kids from lower socio-economic classes were found to feel better about themselves and feel happier overall, than kids from upper-middle and upper-class segments of society.
Honestly, that doesn't surprise me too much. I feel like higher echelons of society put a lot more pressure on kids to perform to a certain level, while laying restrictions on freedom of choice, specifically pertaining to education, careers and friends. Not only that, but we all know that money is the root of all evil; materialism can be a real drag.
The part of the studying that was most interesting to me was the finding that 'Happiness will increase to the extent that individuals are provided with the means to learn skills that can be deployed to meet reasonable challenges...'. So basically, people like to feel like they are learning, growing, and accomplishing something.
That's why I always go back to school whenever I start to feel a little depressed.