In 1969, a young a researcher trained in both medical biophysics and psychology named Peter Levine sat across from a woman he would call Nancy in everything he'd write afterward (a small courtesy, protecting her name while keeping her story intact.)

Nancy had come to him with an impossible catalogue of symptoms (Oh, Nancy. How I relate): fibromyalgia, chronic fatigue, irritable bowel, migraines, panic attacks, and agoraphobia so severe she couldn't leave the house without her husband. Levine had been doing modest, careful work teaching people to relax the muscles in their jaw and neck, watching blood pressure drop twenty points. He began a session with Nancy the way he began all sessions; he had her lie on her back.

It went wrong almost immediately.

Nancy's heart rate began to climb. Then, without warning, it plummeted. She turned white, stared at him, and said: "I'm dying. Doctor, don't let me die." Levine had no protocol for this. There was no roadmap for moments that went this wrong.

What happened next he has described in lectures and books for fifty years, and it still sounds brilliantly unhinged. Levine suddenly had an unconscious image: a vision of a tiger crouching on the other side of the room getting ready to pounce. So he said something a therapist almost certainly should not say. He said: "Nancy, you're being chased by a tiger. Run! Run for the nearest tree!"

Nancy's legs had been seized for two decades, but she began to move, and then started running. (I’m such a New Yorker, when I first read this account, I couldn’t help but wonder about the square footage of his office space.)

The image of the tiger transformed, in Nancy's mind, into an image of her four year old self, held down by doctors and nurses while they forced an ether mask over her face for a tonsillectomy. Suffocating, in sheer terror, she had wanted to escape and couldn't. She was strapped to the table. The energy her body had mobilized for escape had nowhere to go. So it went somewhere else: it went inside. It burrowed into her nervous system and it stayed there for twenty years, disguised as migraines, panic attacks, and an inability to walk out the front door alone.

After that session and a few more, Nancy's anxiety resolved, alongside many of her other physical symptoms. She told Levine, when it was over, that she felt like she was being held by warm, tingling waves.

Levine spent the next fifty years trying to understand exactly what had happened in that room, and what it meant for the hundred million people walking around with their own version of Nancy's tiger.

Levine holds doctorates in both medical biophysics and psychology from UC Berkeley, served as a stress consultant for NASA while the Space Shuttle program was being developed, and refers to his research as "me-search.” His own unresolved childhood trauma drove his inquiry as much as scientific curiosity did. He is not a man given to simple explanations. But the idea at the center of Somatic Experiencing, the body-based therapy he built across five decades, is almost disarmingly straightforward.

Trauma doesn't live in the event. It lives in the body's interrupted response to the event.

Levine observed that animals in the wild rarely develop what he recognized as trauma symptoms, and spent decades building a theory around why. A gazelle gets chased to within inches of death, escapes, and then (this is the part that transfixed him) completes its stress response through physical mechanisms: shaking, trembling, movement, discharging the energy of the threat response. Then it goes back to grazing. The nervous system resets, and the encounter is finished. If you have a dog, you can watch them reset, every time they shake off any stressful encounter.

But humans learn to interrupt this process, and are taught to override our instincts. We tell ourselves to calm down, hold it together, not make a scene. We stop our natural impulse to complete the stressful encounter by pushing the trembling back inside. And the energy that was built for survival has nowhere to go, so it stays inside. If the immobility phase doesn't complete, that charge stays trapped, and from the body's perspective, it is still under threat, still perceiving the world from that perspective.

We do this to ourselves, and to others, all the time. How many times do we interrupt our children when they’re about to have a meltdown? Or when they’re acting wild and racing around? We tame our children out of their natural instincts to shake off their stress and reset. We condition others how we were conditioned, but holding in what is better left expressed sets us up for a lifetime of thwarted growth.

This is why people living with trauma seem to inhabit a slightly different present tense than everyone else. They’re often called dramatic, histrionic, or overly sensitive. When, in reality, they are, in a very literal physiological sense, still inside the original emergency. Their nervous system filed an incomplete report and has been waiting ever since to finish it.

The traumatic event itself isn't what causes long-lasting trauma. It's the overwhelming trapped response, the frozen energy that never discharged, that causes the imbalanced nervous system.

This is where Somatic Experiencing parts ways with most of what we call talk therapy, and why it struck so many people as both radical and strangely obvious.

For most of the twentieth century, healing trauma meant telling the story. You went into a room, you talked, you excavated the narrative of what happened to you, and presumably the light of consciousness dissolved the wound. Talk therapy reorganizes how we think, surfaces patterns, gives language to what we've been dragging around. But Levine's central argument, built from fifty years of clinical work with survivors of every conceivable catastrophe, is that the story is not where the trauma actually lives. The aim of Somatic Experiencing is to access the body memory of the event, not the narrative.

It is not necessary to share the details of your trauma history. (After 27 years of talk therapy, now you tell me? JK. Talk therapy very legitimately saved my life.)

If your trauma is holding you in place, and talking about it re-traumatizes you, you don't have to tell anyone what happened to you. Your body already knows. The work is to go in there.

By emphasizing only cognition and behavior, conventional therapy ignores three critical aspects of coherent experience: sensation, image, and affect. In trauma, the here and now becomes there and then. A smell, a specific tone of silence, the particular texture of someone’s voice, and suddenly you're not in your kitchen in 2026, you're four years old and the terror is indistinguishable from what’s real. So long as we’re still running an old file on new hardware, our nervous system cannot distinguish the difference between then and now.

I know this feeling. For years, entering a new relationship meant being ambushed by a dread I couldn't think my way out of, a full-body alarm that something terrible was imminent, even when, objectively, nothing was. Half a lifetime of talk therapy had given me accurate language for why this happened, but it did not stop it from happening. What I eventually understood was that my feelings themselves needed therapy, not just my thoughts about them. The insight led me to Rita Hayes, an LCSW and Somatic Experiencing therapist, whose first instruction to me was to close my eyes and find the feeling (not explain it, not contextualize it) just find where it lived in my body and describe what it was doing there.

What I found, when I looked, was something ancient. A vibration in the center of my torso. Then the absolute certainty that I was about to be dragged somewhere dark and disappeared.

Hayes introduced me to the concept of "parts" (or Internal Family Systems)— the versions of ourselves frozen at the moment of overwhelm, still responding to the world as though it's the same size it was when they were formed. A person's dread when a partner goes quiet might have nothing to do with the partner. It might be a two-year-old's nervous system still waiting for a parent who was never reliably there. Hayes describes these parts as "un-metabolized traumatic energy."

Simply: it’s unfinished business lodged in the body doing its loyal and exhausting best to keep you safe.

The young part of you doesn't know the difference between the past and the present. It's all the same emergency. And until someone goes in and shows it otherwise, it will keep pulling the alarm: on airplanes, in relationships, in the produce aisle at Whole Foods, wherever, convinced it's doing exactly what it was made to do.

Below, I walk you through what Peter Levine discovered about how to actually stop it, and bring you through what Rita Hayes does, session by session, to make that happen in practice.