What motivates you to be nice and give more? Well here are two recent studies that might offer you some motivation to do both more often.

Nature Online
19 March 2008

Based on the classic interpersonal cooperation game Prisoner's Dilemma, a recent study by Martin Nowak has determined that being nice really does payoff in the long run. Martin is the director of the Evolutionary Dynamics Lab at Harvard University. The study added a "costly punishment" component to the game. A player could choose to punish someone who didn't cooperate. This then penalized the non-cooperative person, while at the same time the other player had to pay to punish. They found that "those people who gain the highest total payoff tend not to use costly punishment: winners don't punish."

Listen to an interview with researcher David Rand (segment actually appears 17:38 in the March 19th 2008 Nature Podcast) that contains a great quote: "Punishment isn't stupid, just the people who choose to punish."

ScienceNOW Daily News
20 March 2008

"Social psychologist Elizabeth Dunn of the University of British Columbia in Vancouver, Canada, wanted to find out what kind of spending really does make people happy. So she and colleagues surveyed 109 UBC students. Not surprisingly, most said they would be happier with $20 in their pocket than they would with $5. They also said they'd rather spend the money on themselves than on someone else. Wrong move. When Dunn's team gave 46 other students envelopes containing a either $5 bill or a $20 bill and told them how to spend it, those who shelled out on others (donating to charity or giving a gift) were happier at the end of the day than those who blew it on themselves (to pay a bill or indulge in a treat).

Dunn says the results "confirmed our hypothesis more strongly than we dared to dream." The effects of altruistic spending are probably akin to those of exercise, she notes, which can have immediate and long-term effects. Giving once might make a person happy for a day, but "if it becomes a way of living, then it could make a lasting difference," she says. She hopes the finding might someday spur policymakers to promote widespread philanthropy that could make for a more altruistic--and happier--population."