GUY RAZ, HOST:
It's the TED Radio Hour from NPR. I'm Guy Raz. So back in the mid-1990s...
ABBY MARSH: I was 19.
RAZ: Abigail Marsh was driving home to Tacoma, Wash. And, Abigail, you actually go by Abby (ph), right?
MARSH: I do. Yeah, I go by Abby in person.
RAZ: Only like high school teachers call you Abigail.
MARSH: That's right, and British people.
RAZ: And British people, right.
RAZ: So on that drive home on the Interstate 5 freeway...
MARSH: It's a big, busy freeway, biggest in the state.
RAZ: ...Abby experienced something that has stayed with her ever since.
MARSH: It was around midnight, and I was crossing over a bridge. And a little dog darted out in front of my car. I was still a pretty new driver, and I did the thing you're not supposed to do, which is swerve to try to avoid it. And the combination of swerving and then unfortunately hitting it anyways sent a car into a spin across the freeway until it finally came to a stop in the fast lane.
RAZ: So the car comes to a halt. And what's the next thing you remember?
MARSH: Well, I remember that it had died. And I don't know why the engine would die from doing donuts but it did. I remember the windows were down because it was a summer night. And I heard a knock on the passenger side. And I turned, and I see a man standing there. And he - all he said was, you look like you could use some help, can I come get in your car? So I said OK, and then he hopped in the car.
I figured out it was still in drive, which is why it wouldn't turn on, and then gunned us across the freeway and parked behind his own car which, like, I remember being a nice BMW. And then he looked at me, and he was like, are you going to be OK? You need me to follow you for a little bit? And I - all I remember saying is no, I'm going to be OK. And he said, OK, you take care of yourself. And he got out and hopped back in his car and drove off.
(SOUNDBITE OF MUSIC)
MARSH: It had always sort of been in the back of my mind because it was such a puzzle, as I think it is for a lot of people. Why would somebody risk their life to help a stranger anonymously and, you know, clearly with no hope in it for any kind of a claim or payoff at all? And he took real risks. And so it just - you know, why would anybody do that?
(SOUNDBITE OF MUSIC)
RAZ: On the show today, Ideas About Why We Help Others. What motivates us to do it? And why are some people just more altruistic than the rest of us, like the man who helped Abby, who darted in and out of traffic on a freeway to save someone he didn't even know? And, by the way, Abby, can you tell us what you do now for a living?
MARSH: Yeah. I'm a psychology professor at Georgetown University.
RAZ: And you are kind of, I guess, kind of best known for studying what?
MARSH: Both psychopathy and altruism I'd say.
RAZ: Here's Abbie Marsh on the TED stage.
(SOUNDBITE OF TED TALK)
MARSH: The events of that night changed the course of my life to some degree. I became a psychology researcher, and I've devoted my work to understanding the human capacity to care for others. The actions of the man who rescued me made the most stringent definition of altruism, which is a voluntary costly behavior motivated by the desire to help another individual. So it's a selfless act intended to benefit only the other.
What could possibly explain an action like that? One answer's compassion obviously, which is a key driver of altruism. But then the question becomes, why do some people seem to have more of it than others? And the answer may be that the brains of highly altruistic people are different in fundamental ways.
But to figure out how, I actually started from the opposite end, with psychopaths. A common approach to understanding basic aspects of human nature like the desire to help other people is to study people in whom that desire is missing and psychopaths are exactly such a group.
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MARSH: So they are characterized by a lot of things, but some of the most consistent findings about them is that they're very bad at recognizing fearful facial expressions.
RAZ: So basically if they see somebody in a vulnerable situation, it doesn't compute?
MARSH: Yeah. And there's a region of the brain under the cortex called the amygdala that we've known for a long time is really important for recognizing other people's fear because people who have lesions in this area show very specific selective deficits in recognizing other people's fear.
RAZ: And what does the amygdala look like in psychopaths?
MARSH: So in people who are psychopathic, it tends to be too small, sometimes maybe 20 percent smaller than that of healthy people.
MARSH: Yeah. Yeah. And we know from brain imaging studies that most people show a strong increase in activation in the amygdala when they look at somebody who's afraid, whereas people who are psychopathic don't.
RAZ: OK, so that was your baseline. And then what was your theory that you came up with?
MARSH: Well, over the years, people have been coming to the conclusion that it's not like there's two kinds of people in the world, psychopaths and everybody else.
MARSH: Psychopathy, like a lot of psychological disorders, exist on a continuum where you can have people at the very far and who are sort of maximally psychopathic and then people who are just a little psychopathic and then the bulk of people in the middle who are not particularly psychopathic.
MARSH: But that continuum suggests that might be only half the equation. It might be that the continuum keeps going in the other direction, so that you have highly psychopathic people on one end, average people in the middle. And then maybe on the other and you have people who are anti-psychopathic, who are unusually sensitive to other people's distress and unusually caring. And so that suggested to me that maybe if you study the people who are extraordinarily altruistic, their brains would look kind of like anti-psychopathic brains.
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RAZ: Abby wanted to test this theory out, so she gathered a group of people you might call extraordinary altruists.
MARSH: Put a bunch of recruitment advertisements out on living kidney donor listservs.
RAZ: Basically people who had donated a kidney to a complete stranger.
MARSH: And we flew about 20 of them into Georgetown and put them in the MRI scanner.
RAZ: And she tracked their brain activity all while showing them the same photos that they had used with the group of psychopaths.
MARSH: We showed them pictures of fearful facial expressions.
RAZ: And then you measured how their amygdala reacted - or the activity?
MARSH: Exactly, exactly. So the fMRI measures blood flow in the brain, and so we will look to see if there was an increase in how much blood was recruited to the amygdala.
RAZ: And did you see, like, wildly active levels?
MARSH: (Laughter) We saw increases in activation of the amygdala. It wasn't like they were totally non-overlapping distributions.
MARSH: But, yes, on average, when we looked at 20 adults who had never donated a kidney to anybody, but were similar to the altruist in every other way that we could think of measuring, on average the altruist showed increased amygdala activity relative to those controls.
RAZ: And what about size?
MARSH: And it was bigger too. So their amygdalas were 8 percent bigger than the controls were on average.
(SOUNDBITE OF TED TALK)
MARSH: But I should add that what makes extraordinary altruists so different is not just that they're more compassionate than average, they are. But what's even more unusual about them is that they're compassionate and altruistic, not just towards people who were in their own innermost circle of friends and family. Right? Because to have compassion for people that you love and identify with is not extraordinary. Truly extraordinary altruists' compassion extends way beyond that circle.
And I've had the opportunity now to ask a lot of altruistic kidney donors how it is that they manage to generate such a wide circle of compassion that they were willing to give a complete stranger their kidney? And I found it's a really difficult question for them to answer. I say, you know, how is it that you were willing to do this thing when so many other people don't? You're one of fewer than 2,000 Americans who's ever given a kidney to a stranger. What is it that makes you so special? And what do they say? They say nothing. There's nothing special about me. I'm just the same as everybody else.
RAZ: So is there a strong biological component to altruistic behavior? In other words, I mean, is it connected to this idea that we need to perpetuate and strengthen our species? We need to make sure it survives and therefore we behave this way because we assume others will behave this way towards us in times of need?
MARSH: So the idea is that because, you know, we humans - we're a group-living species and really very sort of physically vulnerable, and so, yes, as a species, we never would have survived unless we had developed these strong impulses to provide care for the vulnerable and the needy.
So those capacities exist, but it gives us the capacity to feel true care for others' welfare at a psychological level that doesn't have any, you know, this is going to benefit me in the long run.
RAZ: How do other species demonstrate altruism?
MARSH: Well, there have been some really cool studies looking at altruistic behavior in rats where rats will help one another when they're trapped in water or trapped in little confining tubes. (Laughter) rats - I don't work with them myself, but I've - rat researchers have convinced me that rats are pretty cool.
And rats are very good mothers. There are wonderful studies of how rats will walk across electrified grids to retrieve their babies. They're really...
RAZ: Aw, rats. Yeah.
MARSH: Yeah, right. Exactly, exactly.
RAZ: Warmer, yeah - towards rats. So OK - so rats are altruistic. What other species are altruistic?
MARSH: A lot of the higher primates are. Dolphins are, certainly dogs are. Dogs are a lovely example of, you know...
RAZ: They love puppies, just other puppies?
MARSH: Dogs will take care of any species you give them. But there are fantastic stories of dogs that have been given baby skunks, baby owls, you name it, and they have tremendous mothering instincts.
RAZ: It's interesting because clearly those animals are not doing it for selfish reasons. Like, a dog is not looking after a cute, little baby animal and saying, hey, you know, recognize me for all this great altruism that I'm demonstrating. Like, a dog is just doing it. It's just behaving that way.
MARSH: Yeah. You see this creature in need, and you can't help but want to care for it.
MARSH: That's, you know - that's how people are. I would argue that almost everybody has had the experience of encountering a baby animal or a young child in need somewhere that they didn't know, and your just instant urge is to help...
MARSH: ...In those circumstances.
RAZ: But, like, yeah. But the thing that I wonder about the research that you carried out is - and this is the question I'm scared to ask you - is does this mean that some of us are just wired to be better than others?
MARSH: Well, there was a big study that came out - I think it was last year in Nature Genetics that looked across all of the genetic studies that had been down across the last several decades. And they found that on average across almost every human trait, the amount that's dictated by genetic variation is about 50 percent. And I think the same is probably true for altruism.
In fact, there was one study - it was just one, but it did suggest that variation in human altruistic tendencies is about 50 percent due to genetics. But, as we all know, genetics aren't destiny either. And I think it's almost certainly true that most people can become more altruistic...
MARSH: ...The way - well, probably. I mean, we - so we know that society is becoming more altruistic over time. So that suggests that this has to be something that can change.
In fact, you know, we as a people, in this sort of modern world that we live in care so much more about the welfare of strangers than we did in the past. You know, that the fact that we care about the plight of strangers in - who live thousands of miles away from us is actually something really remarkable about us. We do care.
You know, maybe we can't always get our act together to do what needs to be done, but it's like, yes, there are so many people suffering, but we really care about that even though these are people we've never met and will never meet. And isn't that amazing that we still care?
RAZ: Abigail Marsh, she's a professor of psychology at Georgetown University. You can see her full talk at ted.com. On the show today, Ideas About Altruism. I'm Guy Raz, and you're listening to the TED Radio Hour from NPR.
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