Humans have evolved countless thousands of ways to emotionally resonate with one another. Our survival depended upon it for millions of years. Bonding with one another is our greatest survival skill. Our human nature, as a species and as an individual, is to devote ourselves to the love of significant others.
In the book “A General Theory of Love” by three M.D.’s, Lewis, Amini, and Lannon, This thesis is developed in a compelling way. They demolish the contemporary paradigm that ideal love happens between two self sufficient people who do not need one another, focus on responsibility for ensuring their own well-being, and who seek to avoid co-dependent enmeshment. As attractive as that ideal may sound, recent science has demonstrated that such a model is simply wrong. That is not how our bodies behave under the influence of love. We have evolved to depend upon one another for our health, well-being and very satisfaction with life.
Much of the book is devoted to the function of our mid-brain, the limbic system. This is the part of the brain that monitors both the external environment as well as the internal environment, and then makes decisions as to which of the “Four F’s” are our most appropriate response to any stimulating situation: Feeding, Fleeing, Fighting or Fornicating. The limbic system manages our interactions with others to provide us with: resonance, regulation, and revision.
All mammals have a limbic region in their brain, and this is what allows mammal mothers to bond with their young and care for them. Reciprocally, it allows infants to bond with their mother as a primary attachment figure and depend upon her for their protection and nourishment. The limbic system is the seat of love. Humans, whose survival as a species has depended upon staying together in a group at all times, have a particularly well developed set of mechanisms to ensure our cohesiveness with others.
Much of that bond is communicated and maintained through our reading of and sharing our emotions. Mirror neurons in the brain, as one example, are triggered whether we adjust our bodies, or the person we are accompanying adjusts theirs. Mirror neurons are one way that we mentally rehearse another person’s internal experience and assess their current state. Our limbic system reads the emotions of another through their facial gestures, body posture and muscle tone, vocal inflections, their scent, rate of respiration and scores of other means. Most of this perception happens below our level of conscious awareness, because thoughtfulness itself happens in a much more recent part of the brain, the neocortex. Much of our social interaction happens below and inaccessible to conscious thought. Nonetheless, we read others on a deep level and they read us, and this creates a resonance between us.
Even though we may not be aware of it, we do continuously perceive another, just as they are perceiving us, and in that moment our systems begin to co-regulate. We attune our internal body environment to more closely match those who are around us. Each party adjusts closer to the levels of the other: heart rate and strength of pulse, rate and depth of respiration, blood ion levels, muscle tone, immune responses, and countless other metabolic factors have been measured to adjust to those around us. This attunement is easy to see at grosser levels as well. Look at a gathering of connected people on the street, whether they are teenagers, professionals, students or construction workers. Their patterns of dress, their styles of walking, their postures, their communication rhythms have distinct similarities to one another, as well as distinct differences among the various groups. Inside of us, and between us, we are co-regulating ourselves to be more like our associates. I am reminded of a colloquial Spanish expression: “Díme con quién andas, y te diré quién eres,” which translates as “Tell me who walk with, and I can tell you who YOU are.”
This evolutionary mandate to bond with significant others is pronounced in romantic relationships. There is a common knowledge expression that long term couples tend to grow more alike. This is because their limbic systems are not only resonating and regulating, but also revising the very structure of one another’s brains. This is easiest to understand in the infant-mother bond. The infant is born as an open-loop. It does not know how to regulate it’s respiration, sleep cycles, feeding patterns, and thousands of other biological functions. Through being held and tended by the mother the physical system is trained how to respond. The brain functions of the infant are revised from a generous scaffold of possibilities to a template of reinforced patterns of being in the world. Similarly, we implicitly absorb the relationship models in which we are reared, entraining a detailed but subconscious understanding of what love feels like and looks like.
However, these patterns, although deep and strong and organizing of our life and perceptions, can continue to adjust through life, revising themselves in response to new relationships, new people, new experiences. We remain an open-loop system throughout our entire lives. “The General Theory of Love” says that this is why psychotherapy can be effective. By sitting with an attentive listener, one who becomes significant to us, we gradually change the way our brain processes information and, ideally, become more healthy and functional. Similarly, a love partner affects us at a deep level, including how our body functions in the world, and even how we perceive ourselves. The book asserts that our unchangeable human nature requires that we bond with one another to survive, and that we have evolved as beings who love in order to thrive.