Blog post

Examining the altruism of kidney donation

Professor Abigail Marsh discusses her research to investigate the brains of people who have taken the highly altruistic act of donating a kidney to a stranger and why she became interested in altruism in the first place.
Professor Abigail Marsh headshot

Professor Abigail Marsh is fascinated with altruism, the belief in or practice of disinterested and selfless concern for the well-being of others. She directs the Laboratory on Social & Affective Neuroscience, where she has been conducting research to investigate the brains of people who have taken the highly altruistic act of donating a kidney to a stranger.

"If that's not altruistic, nothing is," said Dr. Marsh. "Kidney donors have many opportunities to change their mind and the donors I've worked with have often persisted for months, sometimes even years, to donate their kidney to someone they know nothing about and may never meet."

There is a substantial need for living kidney donors in the United States, with most transplanted kidneys coming from deceased donors. In 2022, just 5,863 out of the 26,308 kidney transplants performed were from living donors. There are currently over 90,000 Americans on the transplant waitlist who are waiting for a kidney.

In her previously published research, Dr. Marsh discovered that the size of the right amygdala in the brains of people who have donated kidneys to strangers is larger than this part of the brain in less altruistic people. The right amygdala is critical in recognizing emotional responses, including fear, and Dr. Marsh's research shows that people who have taken the altruistic act of donating a kidney to a stranger are better at recognizing other people's fear and distress than less altruistic people are. Simply put, people who have given a kidney to a stranger are so affected by the distress and fear someone in need shows that it moves them to donate one of their kidneys to help.

Another noteworthy finding to come out of Dr. Marsh's research is that kidney donors don't see themselves as remarkable. Instead, they possess an incredible amount of humility. "Humility is all about not thinking you're more important than other people, which is another way of thinking about how you value other people relative to yourself," said Dr. Marsh. "Somebody who is humble genuinely values other people's welfare more [than other people do] and this is what distinguishes highly altruistic people [from the general population]."

But while Dr. Marsh's research shows that altruists like living kidney donors may have more humility than the average person, her research also shows that they aren't less risk averse. Nor do they self-report higher levels of empathy, agreeableness, or conscientiousness. These findings are in direct contrast to the answers less altruistic people gave when they were asked what they think sets altruists apart. "[Non-altruists] thought altruists would be saints and good in every way," said Dr Marsh. "But every kidney donor I've talked to really doesn't like being seen as perfect. In some ways, [being seen as perfect] undercuts what they've done because they are a human being who made this lovely decision and this decision is consistent with their values. To them, it seems like the most obvious thing in the world to give to [someone in need of a kidney] in a way that would save that person's life at a relatively small risk to themselves."

In addition to a greater sense of humility, altruists are also more likely to believe that other people are good and less likely to think that a person can be fundamentally evil. "If you're going to give a kidney to a complete stranger, then it doesn't make sense [for you to also believe that people can be irredeemably evil] because giving a kidney to an evil person would be terrible," said Dr. Marsh.

Dr. Marsh's interest in altruism and why people care about other human beings started on a fateful evening when she was just 19 years old. She was driving down the freeway late at night in Tacoma, Washington when a dog ran out in front of her car. After swerving to avoid it, her car started fishtailing and spinning in circles across the freeway. The car eventually came to rest facing backwards and into oncoming traffic. "I was on an overpass, so there was no shoulder for me to escape onto," said Dr. Marsh. "[In addition], the car's engine died, so I really thought I was about to die at that moment too. I couldn't come up with a way to escape."

Then, out of nowhere, a good Samaritan showed up and knocked on her window, asking if she needed help. "I later figured out he ran across the freeway in the dark of night to get to me," said Dr. Marsh. After checking in on her to make sure she was okay, the man ran out into traffic again, got her car working and drove them both to safety. He told her to take care of herself and then was gone almost as quickly as he showed up, leaving Dr. Marsh in a state of shock and awe. "It was a really monumental thing to know that you owe your life to a stranger who put himself at significant risk to help you," said Dr. Marsh. "Ever since that evening, I've been trying to figure out the origins of altruism."

While she has answered some of her questions on the typical characteristics of extraordinary altruists, Dr. Marsh said there are remaining questions that she is pursuing the answers to. "I'm trying to find where in the brain that initial spark is, that decision to help another person," said Dr. Marsh. "Knowing that somebody is in trouble is not the same thing as wanting to help them." In addition, she'd also like to know if and how it is possible to make people more altruistic than they currently are. "We need to figure out how to change the degree to which people value other people's welfare," said Dr. Marsh.

When asked why her research matters and the impact she hopes it has, Dr. Marsh said it all comes back to the basic human need to understand why we do the things we do. "One of the most important questions [that I can think of] about human beings is why we choose to care about one another," she said. "I truly believe that if we could understand the basic mechanisms better, we can improve people's lives. I would love to develop real interventions that improve the degree to which people value the welfare of other people, even people they've never met. When you think about genocides in human history, they weren't caused by people who were incapable of caring about others, they were caused by bad leaders convincing their followers that a particular group of people was not worthy of care. So, if we can turn people's compassion off, we can turn it on too."

Professor Abigail Marsh is the director of the Laboratory on Social & Affective Neuroscience and is a professor in the department of psychology at Georgetown University. She received her doctorate in social psychology from Harvard University and conducted her post-doctoral research at the National Institute of Mental Health.

To learn more about Professor Marsh's research, visit her lab's webpage.

Watch Professor Marsh's TED Talk on altruism here.

To learn more about kidney transplantation and donation, visit our website.


Jenni Muns

Jenni Muns is the associate director of communications at AKF.