Our Responses to Fear Help Us Understand Compassion

Fear is powerful, but so is the feeling it often sparks in others: compassion. The Fear Factor is nominally a book about the first but delves deeply into the latter—the urge to help other people that most humans experience to an extent, some (such as psychopaths) don't know at all, and others feel in abundance. Inspired by an anonymous hero who crossed a highway on foot to save her after her car stalled out, author Abigail Marsh, a psychologist at Georgetown University, explores why people respond to others' fear in diverse ways.
—Matt Huston

You've shown that in children who are at risk for becoming psychopaths, the amygdala doesn't respond normally to fearful faces. Some of them claim not to experience fear. What does that tell us about compassion?

The fact that a population marked by fundamental callousness has difficulty recognizing others' fear suggests that difference is important for understanding compassion. The lack of an amygdala response to other people's fear is an incredibly important link in the chain, because we know the amygdala is essential for experiencing fear as well. If you have difficulty experiencing fear due to amygdala malfunction, why would you have an emotional response to somebody else's fear? And if you can't understand their experience, why would you be motivated to try to alleviate their suffering?

What happens in most brains in response to someone else's fear?

Somehow, there is an internal simulation of the fear. We're still trying to figure out how we experience fear, but it's most likely a set of responses across the brain in regions that are responsible for motivation, subjective experience, and interoception, the feeling of one's own internal state. When they respond in a coordinated way to some external threat, we think that gives you the feeling of fear, and when you respond to someone else's fear, you're recruiting the same circuitry to get an internal representation of it. That's what allows you to label what they're feeling. And the amygdala seems to be responsible for coordinating that response.

How did you come to research extreme altruists, such as people who donate kidneys to total strangers?

We had two-thirds of a continuum: The very low end—callous people who don't recognize fear—and the middle—people who vary in terms of how altruistic they are and how well they recognize others' fear. Was there a high end? Thanks to my experience of being rescued, I have always wanted to understand what would make somebody do something highly altruistic.

You report that the altruists' brains are unusually responsive to fearful faces. You call them "anti-psychopathic." Have you imagined what it's like to be at either extreme?

It's hard to imagine going through the world as impervious to other people's suffering as psychopaths are. It's a disability in some ways. With the altruists it's easier, because most of us can understand feeling the intense desire to help somebody. One summer, my daughter, who was still learning to swim, got stuck underneath an inner tube. Her voice is burned into my brain: "Mommy, help me!" My response was instant: I jumped into the water to get her out of there. Afterward, I was like, "Oh! That's what that feels like." The thought of her in danger was incredibly motivating. It's harder for me to imagine having that same sense of urgency toward strangers.