An ancient part of your brain
determines your response.
6 MINUTE READ
PUBLISHED JANUARY 3, 2018
When Abigail Marsh was 19, a dog ran in
front of her car on the highway. She swerved, spun out, and found herself
facing an oncoming lane of traffic with an unresponsive engine. Across the
highway, another driver saw her emergency lights flashing, pulled over, and ran
to her aid. He pushed her into the passenger seat, kicked her engine into gear,
and drove her to safety. Then he disappeared into the night. She never saw him
again. [Find out more about the science
of why some people are good and others really are not.]
What makes someone put his
life in danger to help a person he’s never met, and why do other people
intentionally cause harm and feel no regret? These are questions Marsh, now an
associate professor of psychology and neuroscience at Georgetown University,
set out to answer. In her new book, The
Fear Factor, Marsh lays out her theory why one ancient part of the brain
controls how we identify and respond to fear.
NINA
STROCHLIC: A stranger risked his life to get you to safety when you were a
teenager. How did this affect the path you took in life?
Abigail Marsh: The combination of a
near-death experience and having a stranger rescue me was an incredibly
emotionally affecting experience. It was hard to shake from my consciousness. The
thing that lingered longest was the fact that a total stranger rescued me. It
seemed so improbable—I could not imagine taking an enormous risk to help
somebody I’d never met.
I had this nagging itch of
wanting to understand why someone would make a decision like that. It was this
puzzle that must have been the engine that drove me.
N.S.: How did you translate
that question into research?
A.M.: It becomes clear to me
looking back that a common thread through my research was an effort to
understand why people want to help other people. This led me to do lab research
about altruistic decision making. But you can’t put people in the position of
making life or death decisions in a lab. So what I did for my post-doc research
was study people who are clinically deficient in care and compassion.
We ran brain scans of teens
with psychopathic traits while showing them images of frightened faces. We
found a lack of response in a part of their brain called the amygdala, an
evolutionarily old structure involved in a lot of emotional and social
behaviors. To contrast that, I picked kidney donors to study because their
behavior was most unambiguously altruistic—with a stranger it can’t be about
reciprocity.
N.S.: When you first launched
your study of children with psychopathic traits, what did you expect them to be
like?
A.M.: I came from a town that
has produced an oddly large number of psychopaths: Ted Bundy, the Green River
Killer, and the D.C. sniper all came from Tacoma, Washington. It’s a myth that
the prototypical serial killer is a psychopath. Now I recognize that a
quintessential psychopath is someone consistently callous in the face of others
suffering. They’re not necessarily out to hurt people, they’re out to get what
they want and if other people get hurt that’s just collateral damage.
Before I assessed my first
child with psychopathic traits I’d taken a training course, which said keep
yourself between the subject and the door and don't carry anything sharp. I had
no idea what I’d be confronting.
When I walked into the room I
could not have been more taken aback. This boy looked like he walked off the
set of a commercial. He had a sweet smile, made conversation and shook our
hands. It was really hard for me to incorporate the fact that he was doing
violent and awful things in his daily life.
That’s called the mask of
sanity. It’s what people found so remarkable about Ted Bundy—those who knew him
thought he was a well-adjusted guy.
N.S.: We tend to think about
how nurture versus nature impacts the way we turn out. What dictates whether
we'll end up as altruists or psychopaths?
A.M.: Every psychological
outcome is influenced by genetic differences and experiences—often 50 percent
is genetic variation. Psychopathy heritability is probably between 50-70
percent. Clearly that’s not the end of the story; life experiences play a role.
The hardest thing about
working with children with psychopathic traits is that I really feel for the
parents. Some parents hope their child ends up in jail because at least
somebody will be taking care of them. We’re all strongly affected by the idea
that children's behavior is affected by what their parents do—we used to
believe that about schizophrenia and autism, too. Bad parenting can cause bad
behavior, but it’s not connected in a major way with serious mental illnesses.
It’s hard to know if parenting
practices can result in people being more altruistic. When I ask people why
they donated a kidney to a stranger, it’s quite difficult for them to answer.
Some say, “That’s the way my parents raised me.” Then I ask, “Well, do you have
any siblings and are they the way you are?” Most will say, “Oh no. Not at all.”
Anyone can come up with an explanation for why they are the way they are, but
it’s very hard to know if it’s true.
N.S.: You chose to study
“extreme altruists” via donors
who gave a kidney to a complete stranger. Why did you end up studying this
group?
A.M.: Altruism is behavior
that benefits someone other than the altruist. But motivations are hard to
measure: It’s socially normative to do little acts like donating blood or
giving to charity. Some people act altruistically to people who have helped us
in the past or will in the future. Others help genetic relatives in a
motivation called kin selection. But it’s really hard to come up with an
alternate explanation for why you’d donate a kidney to a stranger other than
you genuinely want to help somebody because the only benefits are to the recipient.
At the time, there were only
around 1,000 altruistic kidney donors in the whole U.S. and I anticipated it
would be really difficult to recruit. I reached out to the local D.C.
transplant organization and posted some ads on websites and things. I vividly
remember when I opened my laptop I was literally flooded with emails, which has
never happened to me in my entire research career. We had enough people in
days.
N.S.: Tell me about the
amygdala. Before you started researching it, what did you know and what did you
discover?
A.M.: The amygdala is
essential for recognizing other people’s fear. The findings from our initial
studies with children who are psychopathic show a reduced amygdala response
when they’re shown pictures of fearful facial expressions. Their amygdala was
also smaller. This was a really important clue.
People who are psychopathic
have a fearless personality. Amygdala dysfunction impairs their ability to
generate fear response, and identify other people’s fear. They actually can’t
empathize with it. One boy I studied had lobbed a fake grenade into a building
full of people to terrify them. When I asked him if he felt bad, he said,
“Total Kodak moment.”
Altruistic kidney donors
seemed to be the opposite of psychopaths: their amygdalae were larger and more
responsive. People who are highly altruistic are really good at recognizing
other people’s fear and that may be one reason they’re motivated to help.
N.S.: The altruists you
studied often describe a kind of intuition that makes them act before they can
think twice. Why do some people have this and others don't?
A.M.: This is a much deeper
mystery about altruists: How do you get from having a strong response to the
sight of other people’s fear to being motivated to help them?
The evidence points toward a
hormone called oxytocin that is responsible for generating maternal care in the
amygdala. It provides a consistent response to anything that looks infantile,
including other people’s babies, animal babies, or even people who look like
babies—like someone with a wide-eyed fearful expression. I’m betting that
oxytocin in the amygdala is key to making the critical change from “This
person’s afraid, I need to protect myself,” to “This person’s afraid, I’m going
to help them.”
N.S.: How has your research
changed the way you look at human nature?
A.M.: There’s so much sad
news, but the world we live in is not accurately reflected in it. Studying
psychopaths is a paradoxically uplifting experience. Working with people who
really don't care if they hurt people highlights how unlike that most other
people are. We can have blinders when it comes to suffering, but the average
person does care. Trends show that people are becoming increasingly
altruistic to strangers.
There will always be people
out there who won’t be nice, and there’s no evidence we’ll be able to get rid
of the one or two percent of people who cause suffering. But most people are
capable of care and compassion. Studying people who are psychopathic actually
makes me optimistic about everyone else.
This interview has been edited
for length and clarity.
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