It's true, or so claims this study . Research done in University of British Columbia and Harvard Business School on this very unusual topic shows that money spent on another person significantly boosts happiness compared to that spent on oneself. Seems almost counter-intuitive to me, especially considering how morale boosting self-shopping is.
The more I think about it, I feel maybe there is something to this finding, after all. Another way to interpret the results is, if you spend money on people around you and keep them happy, your life will be made easier as well, and consequently, you are happier. In any case, charity is a wonderful thing, and now that there's research showing that the more you give, the happier you are, and there's no better reason to keep up the good work.