The vagus nerve — your body's "love nerve" — activates during compassion and connects heart rate, breathing, and immune response. People with stronger vagal activity show more kindness, deeper social bonds, and a greater sense of shared humanity.
Now, my lab and some other labs have become obsessed with this fascinating part of your body called the vagus nerve. Vagus is Latin for “wandering,” and the vagus nerve starts at the top of the spinal cord, and just think about a couple of things. It's unique to mammals, it is interconnected, some studies suggest, with oxytocin networks which we’re about to talk about. Recent studies suggest the vagus nerve is also related to a stronger immune system response, and very recent evidence in the last year or two suggest that the vagus nerve, as it wanders through the body, regulates your inflammation response to disease. This is one of the great mind-body nexuses in the human nervous system. The vagus nerve wanders through your body, starts right up here at the top of your spinal cord, it goes to muscles in your neck that help you nod your head and orient your gaze toward other people and vocalize. It then drops down and helps coordinate the interaction between your breathing and your heart rate. Every time you take a deep breath, your heart rate slows down. It’s like baseball pitchers three and two count, you don’t see them go (takes a deep breath)—they breathe out to calm down. They vagus nerve controls that relationship between those two patterns. Then it drops down into the spleen and liver, and controls a lot of digestive processes. There used to be certain surgeries for digestive disorders that would sever the vagus nerve, because it regulates the digestive process. It’s this amazing bundle of nerves, and given that it helps you communicate, it helps you empathize by orienting gaze because it’s connected up to oxytocin receptors, and because it’s mammalian, a fellow named Steve Porges said, “This is the love nerve in your body.” It is the caretaking nerve in your body. What a fascinating possibility. So what we’ve been doing in our lab to assess that thesis is we show participants images of suffering and distress, and if you reflect on the image, you may even feel your chest sort of change a little. And then because this is Berkeley, we show them images that create an opposite state, which is pride, so we show our undergrads images of Berkeley like Sather Gate. And this is what’s amazing to me: images of suffering activate the vagus nerve. We have a new study; if somebody tells you an experience of, say their grandparent dying, your vagus nerve fires. If they tell you an inspiring story, their vagus nerve fires—it’s getting ready for feelings of compassion. This graph just shows you when you measure vagus nerve by looking at the relationship between heart rate and breathing we call RSA, the more I feel compassion, the stronger the vagus nerve response. The more I feel pride, the weaker the vagus nerve response. And this really astounds me. I that state of having a strong vagus nerve response, I feel common humanity with many different groups. I’m feeling connected to people with different political persuasions, different ethnic origins, this is Berkeley undergrads, they even admit to feeling similar to Stanford undergraduates, which is a remarkable thing. And that’s the self-other similarity. So these deep ethical intuitions of, “Gee, we have common humanity” are tracking a physiological process, which is really cool. Another way we can study the role of the vagus nerve in compassion and the meaningful life, and social well-being is find people who have really strong vagus nerves, or sort of high levels of activation in that bundle of nerves. You can do it in the lab, you can come to my lab and we could give you a profile of—and we think of this as a temperament—I as a joke called these people “vagal superstars”—that’s how people like to think about them. And what we find is a really interesting profile: if you have a really sort of a strong vagal profile, which you can cultivate through exercise, and recent studies suggest meditation, and other practices—if you have a strong profile, you have more positive emotion on a daily basis, stronger relationships with peers, better social support networks, kids in schools, fifth graders who have a stronger vagal profile are the kids who intervene when a kid is being bullied. And they cooperate, and will donate time like recess time to help a kid who needs help on homework. It relates to altruism and prosociality as well, and they’re trusted more. So another kind of data that says, wow, we think of compassion as this higher order emotion, but it really is tracking part of our nervous system as well.