The psychology of extraordinary altruism

Living donation of a kidney to a stranger is a very rare act of extraordinary altruism and the motivations of non-directed donors are not well understood. Now, a new study by Kruti Vekaria, Abigail Marsh and colleagues provides insights into the psychological mechanisms that underlie the phenomenon of non-directed altruistic kidney donation.

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“Unfortunately, many altruistic kidney donors report that others respond sceptically to their decision to donate,” says Marsh. “Some donors have even told us that the transplantation professionals and mental health practitioners who screened them for donation doubted their motivations. The goal of our study was to examine whether altruistic kidney donors value the welfare of socially distant others more than the average person does, which would support the idea that their donations are motivated by genuine altruism.”

To investigate this question the researchers used a computerized social discounting task in which 21 non-directed altruistic kidney donors and 39 control participants chose whether or not to sacrifice hypothetical resources (money) to benefit others at varying social distances from themselves, ranging from their closest relative or friend to a stranger. “Choosing to sacrifice resources to benefit another person suggests that the person making this choice subjectively values the shared resources more than they value the same resources kept for themselves,” explains Vekaria. “This task has previously shown that people tend to discount or devalue the welfare of socially distant others, and this pattern of social discounting generally follows a steep, hyperbolic decline.”

The researchers found that the altruistic kidney donors had significantly lower rates of social discounting than the control group. In addition, the donor and control groups had similar perceptions of social distance. “This result indicates that altruists don't necessarily feel psychologically closer to strangers than the average person might, and provides evidence that non-directed kidney donors experience genuine altruistic motivation, not just increased self–other overlap,” says Vekaria.

“Our findings support the idea that people vary in the degree to which they value the welfare of socially distant others — those who choose to donate a kidney to a stranger may be on the extreme end of the distribution,” concludes Marsh. “Their motivations appear to be genuinely altruistic, and their decision to donate should be supported.”


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    Vekaria, K. M. et al. Social discounting and distance perceptions in costly altruism. Nat. Hum. Behav. 1, 0100 (2017)

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Carney, E. The psychology of extraordinary altruism. Nat Rev Nephrol 13, 383 (2017).

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