The Science of Happiness: How Relationships Influence Health and Longevity

Over the past few months, I’ve been doing a deeper dive into the research on how happiness will influence health and well-being. It’s probably very intuitive to understand the reason why our happiness would positively affect our health, but I’d like to deconstruct why this is so. But first, defining happiness is important.

Happiness is an interesting word, because we often think about happiness as fleeting moments — a great vacation, a delicious meal, the thrill of a new achievement. But according to research and the great philosophers, it has a much deeper, richer meaning. Aristotle, for instance, called it eudaimonia — roughly translated to "happiness," "flourishing," or "the good life." His intent with this flourishing wasn’t a feeling state per se but a genuine state of fulfillment.

The longest study on happiness, spanning over eight decades, started in 1938, with Harvard’s Study of Adult Development. More than 1,300 descendants and three generations later, we see how happiness influences health, helping us understand what leads to a healthy and happy life. It is the quality of our relationships.

Many other studies have corroborated these findings as well. When we have relationships that are connected, inflammation and cortisol are lower, and the inverse is true. Without connection, cortisol and inflammation are higher, leading to diseases such as depression, heart disease, diabetes, longer healing recovery times, and even early death. 

The autonomic arousal of the sympathetic nerve system, responsible for sending the signal to the body to fight, flight, or freeze, is governed by cortisol. Its opposite companion is the parasympathetic nervous system, which is governed by acetylcholine, which slows things down. This branch is known as the “feed and breed”, “rest and digest.” Also, oxytocin enhances this branch via the ventral vagal cranial nerve. Oxytocin, known as our bonding hormone, augments the dampening of the sympathetic nervous system, calming heart rate, helping us feel calm and connected. We all know when we feel this! It’s the sigh of relief, and I feel safe.

Dan Siegel, MD, UCLA, uses a term to “feel felt.” This is a good way to understand the vagal nerve. When we feel felt, we relax. Its opposite is true. When we feel unseen, unheard, our sympathetic nervous system activates, and the fight, flight, freeze (lower brain regions), and connection is lost. Disconnection is inevitable, and rupture occurs. The brain is hijacked. Our executive function, higher brain reasoning, and empathy center is turned off.

Chronic inflammation, high cortisol, and high adrenaline are markers to illuminate the autonomic nervous system, and where we might be captured in a state of mind of disconnection, dissociation, and withdrawal. Each of these markers is a stimulator of heart disease, diabetes, cancer, dementia, and others. I would suggest if we were encountering these diseases in our lives to also be looking at the quality of our relationships. Dr. Bessel van der Kolk’s book, “The Body Keeps the Score,” elucidates further the connection between chronic stress states with heart disease, autoimmune, digestive problems, sleep disturbances, and other diseases.

Eudaemonia is an antidote to what ails us, and how our relationships can provide a healing suave. But first, we must be connected to ourselves, and that often means a deep dive into our own histories, stories, and where we find ourselves in each moment. It is a felt sense, not an intellectual one. Dr. Siegel coined the term Interpersonal Neurobiology (IPNB) in which he discusses how various parts of our brain come to “know” (gnosis-experiential knowing) a felt sense (connection). He advocates for each of us to essentially clean up our “garbage.”

Siegel says the right hemisphere describes (names it) and the left hemisphere explains it. There is nothing the left brain can do to calm the right brain. The right hemisphere needs to attune or tune into the feeling first. Have you heard the saying “feel it, to heal it?” Once you feel it, you can then name it. Then the left hemisphere may get busy solving the problem, but not before. 

Harvard’s study continues to find that when we engage in relationships that are connecting, meaningful, feeling felt, soothed, and safe, we enjoy greater happiness, and therefore, health. When the researchers asked participants what their greatest achievement was in their lives, it wasn’t how much money they had, or how many accomplishments or awards they received, or how fit they were; it was being a good partner.

In my practice, I have the amazing privilege of witnessing many patients with great connections, and I also see the metrics that corroborate Harvard’s research. Just as well as its opposite. The next time you find yourself missing an opportunity to relate deeply in a relationship, stop and check in with yourself first. When we are genuinely connected to ourselves, we will promote connection to others. Remember name it to tame it, feel it to heal it. Connection reduces all-cause mortality and morbidity. Without good relationships, we live in a state of inflammation, high cortisol, high adrenaline, and disease.

May you know genuine well-being.