What happens in Vagus... may make or break compassion.
© UC Berkeley
Is there a biological fingerprint for compassion?
Two scientific teams, one led by Zoe Taylor
at Purdue and the other by Jenny Stellar
at UC Berkeley, have found that the answer may lie in the Vagus nerve. That's the cranial nerve in the body with the widest reach, influencing speech, head positioning, digestion, and—importantly for these two studies—the parasympathetic branch of the autonomic nervous system's influence on the heart.
Students typically memorize the parasympathetic branch (PNS) as the "rest and digest" branch of the autonomic nervous system (ANS), which controls bodily functions that we're not aware of when we're relaxed and feeling content. The PNS is also called the "feed and breed" branch—and recently, social psychologist Barbara Fredrickson
added the label "tend and befriend" to the PNS, suggesting that it also supports functions that enable social engagement and nurturing behaviors.
These functionally descriptive labels for the PNS—"rest and digest," "feed and breed," and "tend and befriend"—directly relate to the Vagus nerve, which turns out to be something of an enforcer
for the PNS when it comes to the heart and compassion.
Roughly 20 years ago, Steve Porges of the University of Chicago pioneered PolyVagal theory, which suggested that the Vagus nerve fundamentally drives human social affiliation—the motivations and behaviors involved in approaching others in trusting, affectionate, and cooperative ways
. Since then, social science researchers have measured Vagal activity to examine how it relates to social affiliation, particularly related states like empathy, sympathy, and compassion.