Productivity and happiness

It seems to me that the relationship between happiness is as follows: when totally and utterly depressed we have not the ability to work (with the exception of some geniuses); when completely entirely happy and content we have not the will to work. The relationship probably looks something like the following:



As our productivity also influences other peoples' happiness (by making food, clean water, shelter, energy, entertainment etc), society wants each of us to not be at our happiest (on the plus side, neither does it want us to be depressed!).