International Body Psychotherapy Journal

Vol. 18, Issue 1., Mar. 22, 2019

C. Sue Carter

As a sentient species, humans are on the threshold of novel insights into the origins of the magnificent obsession we call “love.” It is well established that healthy relationships can protect against disease and restore the body in the face of illness. Without positive relationships, especially in early life, humans fail to flourish, even if all of their basic biological needs are met. “Love lost” is one of the most powerful forms of stress and trauma. However, the mechanisms through which love protects and heals are only now becoming apparent. Love is most easily understood through the lens of our evolutionary past and in light of our contemporary physiology. At the epicenter of this story is a mammalian hormone, oxytocin, and an even more ancient molecule, known as vasopressin. These biochemical building blocks of love are not unique to humans and are shared with other highly social species. Through the study of social behavior in other mammals, we are also learning that the same physiology that lies behind the healing power of love, reduces inflammation, regulates the autonomic nervous system, the immune system, and even regulates the microbiome. Furthermore, the oxytocin-vasopressin system is regulated by experience across the lifespan, helping to explain the lasting physical consequences of both love and adversity. By examining the biology of social bonds and parenting, we are uncovering pathways that allow humans to experience and embody love. Keywords: oxytocin, love, monogamy, nurture