Forget Survival of the Fittest: It Is Kindness That Counts
A psychologist probes how altruism, Darwinism and neurobiology mean that we can succeed by not being cutthroat.
(…) DISALVO: Your team at U.C. Berkley has done a lot of interesting research on the vagus nerve and its association with altruistic feelings. Tell us a bit about this research and its implications for better understanding the nature of altruism.
KELTNER: The vagus nerve is part of the parasympathetic autonomic nervous system. It is a bundle of nerves that originates in the top of the spinal cord, it activates different organs throughout the body (heart, lungs, liver, digestive organs). When active, it is likely to produce that feeling of warm expansion in the chest, for example when we are moved by someone’s goodness or when we appreciate a beautiful piece of music. University of Illinois, Chicago, psychiatrist Steve Porges long ago argued that the vagus nerve is a care-taking organ in the body (of course, it serves many other functions as well). Several reasons justify this claim. The vagus nerve is thought to stimulate certain muscles in the vocal chamber, enabling communication. It reduces heart rate. Very new science suggests that it may be closely connected to oxytocin receptor networks. And it is unique to mammals.
Our research and that of other scientists suggests that the vagus nerve may be a physiological system that supports caretaking and altruism. We have found that activation of the vagus nerve is associated with feelings of compassion and the ethical intuition that humans from different social groups (even adversarial ones) share a common humanity. People who have high vagus nerve activation in a resting state, we have found, are prone to feeling emotions that promote altruism-compassion, gratitude, love, happiness. Arizona State University psychologist Nancy Eisenberg has found that children with elevated vagal tone (high baseline vagus nerve activity) are more cooperative and likely to give. This area of study is the beginning of a fascinating new argument about altruism-that a branch of our nervous system evolved to support such behavior.
“Performing [circumcision] without anesthetic has allowed researchers to study the parameters of extreme pain in experiments that would not have been allowed on laboratory animals. Using routine, unanesthetized circumcision as a model of stress, Porter et al. were able to examine the relation between cry acoustics and vagal tone in 49 (32 experimental; 17 control) 1 to 2-day-old, full-term normal, healthy newborns during the preoperative, surgical, and postoperative periods. Vagal tone was significantly reduced during the severe stress of circumcision. These reductions were paralleled by significant increases in the pitch of the infants’ cries.”
Male Circumcision: A Legal Affront. Christopher Price 1996
Clinical Studies have demonstrated that the cries of chronically stressed infants, medical compromised infants are characteristically higher and more variable in pitch than those of healthy infants. Other studies have indicated that the vagal tone of chronically stressed infants is significantly reduced in comparison to that of normal infants. A neural model of cry production has been proposed which suggests that decreased vagal tone among infants at risk may, in fact, be related to these increases in cry pitch. Using routine, unanesthetized circumcision as a model of stress we were able to examine the relationship between cry acoustics and vagal tone in normal, healthy newborns undergoing an acutely stressful event.
Vocalizations, heart, and respiratory waveforms were continuously recorded from 49 (32 experimental; 17 control) 1-2 day-old, full-term infants during preoperative, surgical, and postoperative periods. Vagal tone, as measured by the amplitude of respiratory sinus arrhythmia extracted from heart rate data, was significantly reduced during the severe stress of circumcision, and these reductions were paralleled by significant increases in the pitch of the infants’ cries. In addition, individual differences in vagal tone measured prior to circumcision surgery were predictive of physiological and acoustic reactivity to subsequent stress. These results emphasize the potential role of vagal control of the autonomic nervous system during stress.
Newborn Pain Cries and Vagal Tone: Parallel Changes in Response to Circumcision