John Gathright helps a young tree climber discover her potential.
John Gathright helps a young tree climber discover her potential. Credit: Dr. John Gathright

WHAT WOULD YOU DO if you knew that climbing trees could lower pain sensitivity and stress in people with disabilities? If you knew that it could increase the experience of positive emotions while decreasing negative ones?

For Dr. John Gathright, founder of Tree Climbing Japan, the answer to those questions is simple: Get more people into trees!

Toshiko Hikosaka (left) and John Gathright (right) with Treehab participants
Toshiko Hikosaka (left) and John Gathright (right) with Treehab participants; Credit: Dr. John Gathright

Gathright had already been leading tree-climbing expeditions for children with disabilities for close to a decade when he began pursuing a self-designed doctorate in the physiological, psychological and societal benefits of purpose-specific tree climbing programs. After searching in vain for an expert who could help explain and quantify the amazing benefits he’d observed in the course of his work, he realized he’d have to do it himself. By the time his story was presented at the 2013 Partners in Community Forestry Conference in Pittsburgh, it was a story that could bring tears to the eyes of American Forests’ staff, already well aware of the emotional and psychological benefits of trees.

It had all begun in 1997 when 57-year old Toshiko Hikosaka set out to climb a giant sequoia tree in California. In 2001, with Gathright and Tree Climbing Japan’s help, she became the first paraplegic person to do so. The expedition to the top of the 243-foot Stagg tree — the fifth largest giant sequoia — culminated in triumph, wonder … and exhaustion. With Hikosaka too tired to climb down safely, the group spent the night in the boughs under the stars.

John Gathright and a young tree climber reach a treetop
John Gathright and a young tree climber reach a treetop; Credit: Dr. John Gathright

But the finish line of Hikosaka’s climb up the Stagg tree was just the beginning of another dream. Her strength and resilience is inspiring and uplifting, but not, as Gathright would discover, unique. Later, after they had returned to Japan, he found that a documentary of Hikosaka’s climb had left people all over Japan hankering to follow in her footsteps. In particular, he met many children who wanted to experience “treehab” — rehabilitation therapy through tree climbing — the adaptive tree climbing techniques that Gathright had developed with Hikosaka. So Gathright led the founding of the nonprofit Treehab, specializing in tree-climbing rehabilitation and therapy. Soon, Gathright and the others at Treehab were seeing tremendous changes in the children’s moods and outlooks. As Gathright puts it, “Little miracles were happening all over Japan up in the trees” as the little climbers felt less pain, as their depression eased and as more smiles and laughter rang through the treetops.

And so Gathright soon found himself working with other researchers at Nagoya University, asking the question, “How do people change when they climb trees?” They measured pulse and stress hormone levels on the ground and again in the trees. They studied pain sensitivity. Time and again, their research showed the positive effects tree climbing was having on the kids. Even more interesting, they collected the same data while climbing concrete towers and discovered the effects were not as strong — not even when the tower was in the same forest. It wasn’t just the climbing. It was the trees.

Today, Treehab has helped thousands of children with physical disabilities and emotional trauma discover their inner tree climber and boost their confidence. Gathright found that the more you learn about how trees can help people — he calls trees our friends, teachers and doctors — the more you’re compelled to harness their power. American Forests continues to protect and restore forests so that future generations can also experience their healing presence.

Learn more about John Gathright and Treehab in the TED Talk “Out on a Limb — The Healing Power of Trees,” available on 

Dr. John Gathright giving a TED Talk in Kyoto, Japan
Dr. John Gathright giving a TED Talk in Kyoto, Japan; Credit: TEDxKyoto