The Science of Kindness

A Q&A With Dr. Kelli Harding, author of the "Rabbit Effect"

Kelli Harding, MD, MPH, an assistant clinical professor of psychiatry at Columbia University, researches the science of kindness and the social dimensions of health. She began her career working on the front lines of emergency psychiatry before pivoting to a specialty in mind-body medicine, which emphasizes a holistic view of health where human connection, purpose, and our environment are as important as anything that happens at the doctor’s office. 

We talked with Dr. Harding to learn more about her book, The Rabbit Effect: Live Longer, Happier, and Healthier with the Groundbreaking Science of Kindness, and about the hidden factors that make us healthy.

Tell us about The Rabbit Effect and why it became inspiration for your book.  

In 1978, researchers looking at the connection between high cholesterol and heart health in rabbits made a startling discovery. Feeding the rabbits the same high-fat diet, the scientists expected that all would have similar clogging of their arteries. Yet one group had 60 percent fewer fatty deposits than the other. Eventually, they identified the variable: the group that had significantly better health outcomes was under the care of an unusually affectionate researcher who talked to them, cuddled and petted them, while the other group were simply  fed. In other words, she was kind. The rabbit study was  just the beginning of what we now know from decades of public health research—our social world is the major predictor of our health. As a medical doctor, I was shocked to learn medical care, while critical, only accounts for about 10-20% of our overall health status. Instead, much of good health depends on creating supportive relationships in our homes, neighborhoods, schools, workplaces, and communities. This means every person’s kind or unkind choices in their daily lives makes a difference in the health of others. As soon as I understood this, I knew I needed to write the book and spread the word.

When you were researching the book, what did you learn about the role that positive emotional connections play in good health?

Kind, supportive relationships are essential for good health and help us navigate life's inevitable challenges. For example, consider a difficult situation you were in that was made better by having a loved one or trusted friend by your side. What's great is the data supports what we know intuitively as human beings—we feel better when we know someone else has our back. Kind, supportive relationships lower stress, the risk of chronic diseases, promote better immune functioning, better lifestyle choices, sleep, and mental health.

We all need a reason to get out of bed in the morning, and positive emotional connections to others, our community, or our work can provide a sense of motivation and purpose. Increasing data shows people with a sense of purpose live longer and function better even with serious illness. I've watched with awe how some patients beat the odds with serious illness to make it to a significant milestone in their lives, such as a child's wedding, finishing a project, or a special birthday celebration. Every human being, even those being cared for, needs to feel needed and that their life matters.

You spent many years working as an MD on the front lines of emergency psychiatry before pivoting to a specialty in mind-body medicine. How has this holistic approach changed the way you treat and relate to patients?

Working in the ER for many years, I developed a deep appreciation that those who often struggle the most with an illness have a history of adversity, such as limited social support, education, income, insecure housing, or experienced discrimination or trauma. To better understand why, I enrolled at Columbia's Mailman School of Public Health, and—wow! Combining the biopsychosocial model of medicine with population health data and knowledge of positive psychology, a broader, more comprehensive view of health emerged. This holistic view includes biomedicine, social health, and emotional wellness. Once I understood the data, I wanted to empower as many people as possible to improve their health, not in the usual ways like diet and exercise, but by cultivating kind, supportive relationships in all areas of their lives.

My experience in the ER changed me profoundly in another way too. It is clear to me now that when I left before the pandemic to do outpatient work, I was experiencing symptoms of burnout. I didn't have the language or framework to fully describe my feelings at the time. Instead, I felt demoralized and exhausted, so I left a job I loved. This experience and the tragic suicide of Dr. Lorna Breen during the pandemic highlighted that we must do a better job with self-care and caring for each other as caregivers.

How do you leverage the idea of kindness and other holistic approaches to wellness with patients who are struggling with debilitating mental health conditions, like medication-resistant depression and chronic anxiety?

Every illness occurs in a social context. If we ignore it, we may fix the problem but ultimately fail the patient. For example, we can treat resistant depression or chronic anxiety with a new medication, but if the person feels chronically lonely or socially isolated, is in an unsafe living situation or relationship, or toxic work environment, we may have missed the bigger picture.

As psychiatrists, we can address what is happening in the body physiologically and emotionally and be mindful of what's happening in the person's daily life. While we can't always fix the conditions of someone's life, we can at least acknowledge that they are playing a role, support the person, and help them advocate to make things better. Psychiatry has been at the forefront of holistic care for a long time with interdisciplinary teams with medical, social work, peer support, and different forms of behavioral therapy. We are well-positioned to expand and lead the rest of medicine in this model.

What are some of the tools you give to patients struggling with physical ailments that you sense are rooted in psychological issues? 

One tool is to teach patients about the profound interplay between the mind and body and making it ok to talk about the role of emotions in physical health. From the remarkable data about adverse childhood experiences (ACEs), we know that trauma is widespread and has profound implications for our physical health if not addressed. As a clinician, it is a privilege to help people live up to their full potential no matter what has happened to them. 

Other tools to help people get unstuck and find joy in life no matter what illness they face may include forgiveness, creating meaning, building community, finding a new sense of purpose, learning to advocate for oneself, connecting with awe, practicing self-kindness, or having more fun. My hope with the book is to offer clinicians more evidence-based ideas from public health and positive psychology to help people feel and function better.

Most agree that the pandemic and consequent lockdowns triggered the spike in mental health issues we’re seeing now. What are your recommendations for people struggling to recover as we enter a post-COVID world?

Accepting that things are different than before the pandemic and learning to move forward is a process. There has been so much loss—from opportunities, education, jobs, communities, and loved ones. My dad died at the start of the pandemic, and the pain felt amplified and prolonged by the inability to grieve in the usual ways. There is an expression that brings comfort: change is inevitable, growth is optional. Let's hope we will take what has happened to us as individuals, communities, and systems to make things better for each other going forward.

The big silver lining and the call to action of the pandemic is that mental health has come out of the shadows. People are talking about it more openly than ever before, even our nation's Surgeon General, Dr. Vivek Murthy, which is very encouraging. The crisis provided an opportunity to address significant challenges that existed even before the pandemic, such as young people's mental health, social isolation, and loneliness.

You write about the ripple effect of kindness: that people can “pass on” acts of kindness that they receive. What kinds of acts of kindness are known to be the most beneficial to self and others?

Kindness is incredible because it costs nothing and benefits the doer, receiver, and anyone watching. Even small acts of kindness can boost our mood, make us feel more connected to others, and want to pay it forward. The kindness data shows that your actions matter. This could be saying good morning to someone you pass by, waving at a neighbor, asking the cashier how their day is going, thanking a co-worker, or picking up a piece of trash on the sidewalk. In NYC, I like to thank the subway conductor when I get off the train. Their smile of surprise makes my day!

The ripple effect of kindness happens in the million tiny moments of our everyday lives. For example, the hug you give your partner walking out the door in the morning may mean they are more likely to let someone pass in front of them on their commute to work. That person, in turn, may arrive at their work in a better mood and compliment a co-worker on a job well done, and that co-worker may decide to start a new project because of the encouragement, and so on. Of course, the most beneficial acts of kindness are the ones you choose to do, so please pick something that feels authentic to you and be kind!

Media Contact

Carla Cantor
Director of Communications, Columbia Psychiatry
347-913-2227 |