Most of us have felt the satisfaction that comes from spending money on another person, whether it be a gift for a friend or a donation to disaster victims. Now an international team of psychologists report that the relation between generous spending and happiness holds around the world, even in countries as impoverished as India and Uganda. “Here in North America we might think we have the luxury of extra money to spend on others, whereas people in poorer places might be better off spending their limited resources on themselves,” says the study's lead author, Lara Aknin of Simon Fraser University in British Columbia. “But we see that generosity is rewarding in rich and poor countries.”

This conclusion comes in part from a sweeping survey of 200,000 adults in 136 countries, who answered questions about both their charitable donations and their subjective well-being. After household income and other demographic factors were taken into account, a positive link between donations and happiness emerged in 120 of these countries, rich and poor alike, and the boost in well-being from having given in the past month was as high as it would be if the respondent's household income were to double, according to the survey responses.

The researchers then ran several experiments to test if giving actually caused the happiness boost. For example, participants in Canada and South Africa, the latter a nation with much lower per capita GDP, were randomly assigned to buy a goody bag either for themselves or for a sick child in a local hospital; in both countries, those who had spent the money on the anonymous child reported feeling happier than those who had spent the money on themselves.

The experiments yielded a robust cross-cultural consistency, according to the studies published in May in the Journal of Personality and Social Psychology, supporting the idea that the relation between giving to others and our own well-being is a universal human trait. Indeed, other recent research agrees. In an experiment Aknin and her colleagues published in January in PLOS ONE, toddlers too young to talk or to have been taught to share smiled more when sharing a treat than when receiving a gift. Moreover, in a set of studies published last year in Nature, researchers showed that giving was more spontaneous than greed, which required more thought.

Aknin believes giving feels good the world over for the same reason that eating and sex do: we have in our brain a naturally selected system of short-term rewards for behavior that aids long-term survival. None of our ancestors could survive on their own, Aknin points out, “so if generosity fostered social connections, then it might have been a really adaptive strategy.”