Nature Grows Love: The Living World Was Built to Bond With You

Two ways of knowing, held together

Before the studies, a word on how I want to hold them. Robin Wall Kimmerer, a botanist and enrolled member of the Citizen Potawatomi Nation, writes about braiding indigenous knowledge and Western science together as two languages describing the same living world, neither one subordinate to the other. Science measures. Lineage knowledge relates. A controlled study isolates one variable at a time and tells you what it can prove within that narrow frame; a people who have planted, foraged, and grieved on the same land for generations know it as kin, and that knowing is not lesser just because it cannot be reduced to a p-value. I am going to walk you through some real research in this piece — soil bacteria, oxytocin, awe — and I want to be honest about where that research is strong and where it is early. But the underlying claim, that the earth is built to connect us to each other and to itself, is not waiting on a lab to be true. Science is catching up to something people who worked the land already knew.

Dirt and your mood: the soil bacteria story

Start with something almost too simple: putting your hands in the dirt. There is a specific bacterium living in ordinary soil, Mycobacterium vaccae, that has become one of the more interesting threads in this research. In a widely cited 2016 study published in PNAS, researchers led by Christopher Lowry's group found that immunizing mice with a heat-killed preparation of this soil bacterium promoted resilience to chronic stress — the treated mice showed fewer submissive, avoidant responses when exposed to an aggressor, calmer behavior on standard anxiety tests, and a dampened inflammatory response compared to untreated mice. Separate work from the same research line found the bacterium increased activity of tph2, the rate-limiting enzyme your body uses to build serotonin, specifically in a brain region called the dorsal raphe nucleus — in plain terms, exposure to this soil microbe turned up activity in some of the very neurons that produce serotonin.

• This is animal research, not a human clinical trial — I want to be precise rather than exciting about that. Nobody has shown that gardening cures depression, and no one should tell you it does.
• What the research does support is a real, mechanistic pathway: an ordinary soil bacterium interacting with stress-regulation and serotonin-related circuits, in a direction that looks protective rather than harmful.
• Researchers call this the "Old Friends" hypothesis — the idea that our immune and nervous systems co-evolved alongside everyday environmental microbes, and that modern life has quietly cut off an input those systems were built to expect.

What this means, and does not mean

I want to slow down here because this is exactly the kind of finding that gets oversold. "Soil bacteria cure depression" is not a claim the evidence supports, and I will not make it. What the evidence does support, honestly stated, is that soil-derived microbes appear to support mood-regulation and stress-response pathways in animal models, and that this sits inside a much older, much less controversial observation: people who spend real time with their hands in the earth — gardeners, farmers, anyone who has knelt in a garden bed at the end of a hard week — have always described it as restorative. The lineage truth here does not need the mouse study to be valid. But the mouse study gives us one plausible, physical reason why the ancestral practice might work the way generations of people already said it does. That is what two ways of knowing looks like in practice: neither one waiting for permission from the other.

Touch, oxytocin, and the biology of bonding

Nature also reaches you through skin. Oxytocin is a hormone released during touch, closeness, and warm social contact, and the research on it is some of the more solid work in this space. Studies on affectionate touch — a hand on a shoulder, a hug, skin-to-skin contact — show it reliably triggers oxytocin release and tracks with lower reported anxiety and stress, along with reduced cortisol, the body's main stress hormone. Researchers now describe oxytocin less as a simple "love hormone" and more as a signal that turns up the emotional and social significance of what is happening around you — it makes closeness feel like it matters, biologically. Direct contact with the earth — bare feet on grass, hands in soil, skin against bark or water — is itself a form of touch, and it is worth noticing that most nature contact already comes bundled with the very touch and stillness we know supports this system.

Awe, the small self, and why old forests matter

Then there is what happens when you stand in front of something genuinely vast — an old-growth forest, a wide sky, a coastline. Psychologist Paul Piff and colleagues ran a set of five studies, with over two thousand participants, testing what awe does to people. Across every study, awe-inducing experiences — many of them nature-based — produced what researchers call the "small self": a temporary, measurable shrinking of self-focus, paired with an increase in generosity, ethical decision-making, and broader moral concern for others. In plain terms, standing in front of something bigger than you are appears to quiet the part of the mind that is usually keeping score for itself, and that quiet makes room for other people. This is not a fringe finding — it replicated across different populations and different awe triggers, most of them drawn straight from the natural world. An old forest is not just scenery. It appears to be a functional invitation to feel smaller and connect wider.

The kinship Kimmerer names, and why it fits the biology

This is where the science and the lineage knowledge braid together rather than compete. Kimmerer describes a grammar of animacy — language that treats the living world as kin, as "who" rather than "it" — and a reciprocity at the heart of how traditional peoples related to land: the land gives, and you give back, rather than simply taking. That is not a poetic flourish layered on top of biology. It describes, in relational language, the same thing the serotonin pathway, the oxytocin system, and the small-self research are describing in mechanistic language: we are wired to bond with the living world, not to stand outside it and extract from it. Reciprocity is not just an ethic that happens to be nice. It may be the natural expression of a nervous system built to connect with what is alive around it, including soil, plants, and old trees, not only other people.

The invitation, not the prescription

None of this is a mandate, and none of it is fear-based. Nobody needs a soil-bacteria protocol or an oxytocin target to hit. What it is, is permission — to take seriously something you may have always suspected: that digging in the dirt, touching the actual earth, and standing in an old forest are not indulgences you schedule when you have spare time. They appear to be part of the design, and the science, young and honest as it still is, keeps pointing the same direction the lineage knowledge always has. So dig in the dirt without gloves sometimes. Put your bare feet on the ground. Go find an old tree and stand under it for a while, longer than feels efficient. You do not need a study to give yourself permission to do this, but it is nice, and reassuring, when the study agrees with what people have always known.