Title: People Who Donate Kidneys to Strangers Value Them as Much as Family, Friends

A new study published by a Georgetown expert on altruism shows that individuals who give strangers a kidney value the welfare of strangers nearly as much as family or close friends.

Abigail Marsh, an associate professor of psychology and neuroscience, worked with Georgetown Ph.D. candidate Kruti Vekaria and other students on the new study on altruism published today in the scholarly journalNature Human Behavior.

“The interesting thing about extraordinarily altruistic people is that they are willing to take significant risks and costs not just to benefit a family member or close friend, but to benefit a stranger,” says Marsh, who has done previous studies on extreme altruism.

“Whereas most people are willing to sacrifice to help people close to them, how much they are willing to sacrifice drops off considerably for more distant acquaintances or strangers.”

Social Discounting

Marsh says psychologists call the tendency to devalue the welfare of people who are distant as opposed to people close to them “social discounting.

“Many people might sacrifice something for a friend or neighbor, but if it’s someone they don’t know who lives 500 miles away, they are less likely to help,” Marsh explains, “But extraordinary altruists, such as the people who give kidneys to strangers, don’t seem to discount the welfare of distant others nearly as much.

For the study, Marsh and Vekaria measured social discounting in 21 altruistic kidney donors versus 39 control participants.

All the participants completed a computerized social discounting task, during which they made nine dichotomous choices about keeping or forgoing resources to benefit each of seven target individuals who ranged in social distance from 1 (closest) to 100 (furthest).

“We found they will sacrifice as much for their 100th closest relationship as the average person will sacrifice for their 20th closest relationship,” Marsh says.

Valuing Strangers

The study authors say their findings add to a growing body of research that demonstrates social discounting can “meaningfully measure altruistic motivation,” and provide evidence that increased subjective valuation for the welfare of distant others, rather than misperceptions of social distance, can predict real-world generosity.

“The results from our study provide insight into not only what motivates extraordinary generosity, but also the underpinnings of altruism in general,” says Vekaria, who is listed as first author on the paper. “While they do differ in their social discounting, we found that extreme altruists and healthy controls don’t differ in their social distance perceptions. “This means that the extreme altruists don’t necessarily view themselves as any ‘closer’ to strangers. They actually just value strangers differently.”

Marsh adds that the study also shows that “it is actually possible for people to value the welfare of even people very distant from them, which is a reason to be optimistic about the average person’s capacity for generosity.”