January 7, 2016 – People, including those who exhibit “extraordinary altruism,” consistently reject offers of below one-third of a total stake even when it means they won’t get anything, according to a new study by Georgetown psychology professor Abigail Marsh and Georgetown graduate student Kristin Brethel-Haurwitz.
In an economic game, study participants were told that an anonymous fellow participant had received a stake of money (for example $10) that could be shared between them.
Participants then learned how much their partner had offered to share and could either accept or reject the offer. If a participant rejected the offer, neither participant would receive any money.
People in the study included both altruistic kidney donors, all of whom had donated a kidney to a stranger, as well as a control group of people who had not donated a kidney.
The altruism study, published today in Scientific Reports, found that all participants tend to reject offers that were less than a third of the total stake, or under about $3 in the example. People who had donated kidneys to strangers were equally likely as other adults to exhibit this behavior, according to the study.
“Rejecting unfair offers is sometimes called altruistic punishment because it is theorized that people do this ‘irrational’ thing to punish the other party for being unfair, which may, in turn, prevent that person from acting similarly unfairly in the future, to the benefit of other people,” says Marsh, who studies altruism and recently authored a pioneering study on the brain structure and function of kidney donors.
Outside the Lab
“Our team theorized that if punishing inequity is motivated by altruism, extraordinary altruists would punish more frequently,' she adds. “But what we discovered is that extraordinary altruists punish the same amount as everyone else.”
Marsh says the findings "support the concept that what we think of as altruistic punishment is better termed ‘costly punishment’ and may be motivated by social, but not necessarily pro-social, concerns. Our results also support prior suggestions that self-reported altruism may not reliably predict altruistic behavior.”
Marsh says the study also reinforces the importance of looking outside the laboratory when studying important positive behaviors such as altruism.
“People who have engaged in highly altruistic behaviors in the real world may be able to teach us things about altruism that can’t be learned using economic paradigms or questionnaires,” Marsh says.