, and It Goes Up — The Secret of Thankfulness
One of my favorite sayings about relationships is this: Gratitude breeds more gratitude. When I receive a gift, I believe its true value lives not in the price tag but in the card tucked inside. Even a modest gift, if it comes with a heartfelt note full of genuine thanks, is transformed into something priceless — a treasure that reaches right into my chest.
On the other hand, even the most expensive designer gift, if it arrives without a card, feels oddly hollow. It might be useful, sure, but it does not move you.
At the start of last year, while setting my annual goals, I found myself thinking about all the people who had helped me. One by one, I called each face to mind and wrote a long email — not a handwritten letter, though I wished it were — spelling out exactly what they had done for me and what had come from it. As I typed, a huge smile spread across my face. In some cases, tears came. It was one of the happiest, most meaningful exercises I have ever done, and the replies I got back told me the feeling was mutual.
Gratitude Rewires the Brain
I have two sons. More accurately, I have two sons who are raising themselves with impressive competence — and for that I am deeply grateful. My older son is currently in Canada, somehow looking after his younger brother, a high school senior eight years his junior. Because both boys left the nest, my wife — who had spent her entire adult life supporting the kids and me without ever getting to use her own professional training — was finally able to start working in Korea. I cannot overstate what a gift that has been.
When the boys still lived at home, our family had a Sunday tradition: we took turns leading a prayer of gratitude. These were not the self-centered kind where you rattle off a wish list. They were expressions of genuine thanks — for each other, for what we had, for every quiet blessing we could identify. Something curious happened. During weeks when we did these gratitude prayers, our younger son's behavior shifted noticeably. He was more engaged, more cooperative, more present. Even the turbulence of adolescence seemed to calm. At the time, I was skeptical. Can a gratitude prayer really tame a teenager?
Then I came across the work of Professor Antonio Damasio at the University of Southern California, and my skepticism evaporated. Damasio and his team hypothesized that gratitude would activate brain regions tied to morality and value judgment. To test this, they showed participants video interviews with Holocaust survivors — people who had barely escaped death in Nazi concentration camps thanks to the help of others — while fMRI scanners mapped activity in their brains.
The degree of gratitude each person reported was tightly correlated with activation in two areas: the medial prefrontal cortex (mPFC) and the anterior cingulate cortex (ACC). The medial prefrontal cortex handles planning, execution, impulse control, meaning-making, and concentration — it is the brain's command center. The anterior cingulate cortex regulates emotion, processes pain, and plays a major role in reward anticipation, decision-making, impulse control, and moral reasoning. Could the transformation I had seen in my son during gratitude-prayer weeks have been driven by exactly these brain changes?1
Gratitude Summons Oxytocin
I mentioned earlier that for me, a gift's real value lives in the card, not the box. A study from the University of Tsukuba in Japan speaks directly to this. Researchers asked one coworker to write a thank-you letter to another and read it out loud. They then scanned the brain of the person listening. The results were clear: the listener's prefrontal cortex lit up with activity, while anger, depression, fatigue, and anxiety all dropped. The listener's emotional state shifted measurably toward the positive. One letter, read in one sitting, was enough to reshape the neurochemical landscape of another person's brain. When we call human beings "social animals," what we really mean is that we are built for reciprocity. We express emotions to each other, and we respond to the emotions directed at us. Do not fight this. Do not resist it. It is how we are wired.2
Not long ago, I splurged on a summer camp for my younger son. When he got back and I called him, I was quietly hoping for some appreciation — the camp had not been cheap. His response was the exact opposite. "Why did you sign me up for such a terrible camp?" he demanded, unleashing a torrent of complaints. I felt the anger rise — a sharp retort was on the tip of my tongue — but I summoned a restraint I did not know I had. No. Steer this toward gratitude. Find the positive. I took a breath and said, "But it must have been interesting, right? Living with kids you had never met before — was that not kind of fun?"
Slowly, reluctantly, he began to find the good in the experience. That is how gratitude works. When one person genuinely thanks another, the person hearing it feels warmer, and a natural desire kicks in to do something worthy of even greater thanks.
Research backs this up. People who receive expressions of gratitude become kinder — not just to the person who thanked them, but to complete strangers as well. Gratitude breeds more gratitude, and that gratitude ripples outward, quietly making the world a more livable place. This brings to mind the movie Pay It Forward, in which an eleven-year-old boy named Trevor, given a school assignment to find a way to change the world, builds a cascading chain of kindness. He does something generous for three people and tells each: "Don't thank me. Pay it forward."3
Here is what makes all of this even more remarkable. The medial prefrontal cortex and anterior cingulate cortex are densely packed with oxytocin receptors. This suggests two possibilities, both fascinating: people with naturally higher oxytocin may express gratitude more often, and the act of exchanging gratitude may itself raise oxytocin. Professor Paul Zak's team had 41 adults over age 65 inhale oxytocin for ten days and then ran a battery of psycho-physiological tests. Of all the changes they measured, the most significant was an increase in the feeling of gratitude.
We already know that mutations in the CD38 gene — which helps regulate oxytocin secretion — or in the oxytocin receptor variant rs3796863 are linked to reduced sociability and higher risk of autistic traits. In a recent study, couples who underwent simple gratitude training — "When your partner does something you appreciate, take a moment to say 'thank you'" — spent significantly more time together voluntarily and reported stronger positive feelings across nearly every area of their relationship. The study showed that CD38 mediated these effects. And here is the kicker: CD38 is also closely tied to immune function. It is possible that every time we practice gratitude, our immune system quietly strengthens and our bodies get healthier. So before you spend more money on supplements to boost your immunity, try telling the people closest to you that you are grateful.4