Somatic Experiencing is a mind–body approach to the treatment of trauma developed by Peter A. Levine, Ph.D. His seminal book, Waking the Tiger: Healing Trauma, presents findings from over forty years of research in the field of traumatology. Dr. Levine holds a Ph.D. in medical biophysics from the University of California, Berkeley, as well as a doctorate in psychology from International University. In developing Somatic Experiencing, Levine turned to the wisdom inherent in nature, closely observing the behavior of wild animals. He sought to understand why animals are consistently able to return to normal functioning after traumatic events, while humans so often develop lasting adverse effects.
To begin exploring Levine’s findings, it is important to understand the role of the Autonomic Nervous System (ANS) when we are faced with threat. Like wild animals, the human nervous system is biologically wired to detect danger and to assess whether an environment is safe. Psychophysiologist Stephen Porges termed this involuntary, non-cognitive ability to perceive safety or danger “neuroception.” Through neural circuits operating outside of conscious awareness, we continuously evaluate whether situations or people are safe, dangerous, or life-threatening.
When an environment is perceived as unsafe, the body automatically initiates defensive responses. The most primitive of these is the orienting response. For example, if we were walking through a forest and heard a sudden sound in the bushes, we would instinctively stop, look, and listen in order to identify the source and location of the sound. If the threat is confirmed, the body prepares for one of three primary survival responses: fight (aggression), flight (escape), or freeze (overwhelm or “playing dead”).
Each of these defensive responses is governed by specific pathways within the sympathetic and parasympathetic branches of the ANS. The hypothalamus serves as a central regulator of these processes, and through the hypothalamic–pituitary–adrenal (HPA) axis, energy is mobilized for survival. Understanding these innate defensive mechanisms is essential to grasping Somatic Experiencing’s core strategy for resolving traumatic stress.
Levine observed that unlike humans, wild animals are able to move out of intense sympathetic arousal—fight or flight—and parasympathetic immobilization—freeze—after a threat has passed. When animals return to a sufficiently safe environment, they instinctively engage in spontaneous bodily movements such as shaking, trembling, or stretching. These movements appear to help discharge the high levels of survival energy generated during the threat and allow the nervous system to return to equilibrium. Only when safety is restored—and neuroception registers this safety—can the body release its defensive guard. At that point, animals naturally complete the motor action plans of self-protection that were interrupted during the attack. This completion is biologically essential for survival and restoration of balance.
A classic example shown in Somatic Experiencing trainings illustrates this process. In the video, a polar bear is chased by a helicopter, triggering a powerful flight response. The bear runs with tremendous effort until it is struck by an anesthetic dart and collapses into immobilization. As the anesthesia wears off, the bear begins moving its legs as if running, followed by shaking, twitching, and convulsing before returning to normal behavior. These movements are not random. Rather, the bear is completing the interrupted motor action plan of escape and discharging the enormous amount of survival energy mobilized during the chase.
During the pursuit, the bear’s nervous system summoned intense energy and adrenaline to ensure survival. When the dart interrupted this response, that energy became trapped in the body. Once the environment was again safe, the bear’s nervous system instinctively allowed the completion of the flight response, gradually shifting from sympathetic activation back into parasympathetic regulation. Through this discharge, equilibrium was restored.
This process is central to the Somatic Experiencing model. The body must be allowed to complete defensive responses in order to fully resolve traumatic activation. Wild animals do this naturally; humans often do not. When this discharge does not occur, the nervous system remains stuck in heightened or collapsed states, contributing to post-traumatic stress symptoms.
Another survival response shared by humans and animals is the freeze response. Levine became particularly interested in this state because of its prevalence in human trauma. Freeze is a last-resort defensive response that occurs when escape or resistance is perceived as impossible. It is nature’s compassionate mechanism for reducing pain and terror, often accompanied by the release of endorphins and a sense of dissociation. While freeze is commonly associated with life-threatening events, it can also arise in situations that simply overwhelm the nervous system.
Although individuals in a freeze state may appear low-energy, depressed, or disconnected, beneath this immobilization lies a tremendous amount of bound survival energy. Levine observed that humans often struggle to emerge from this state, leaving them feeling collapsed, numb, and disconnected—symptoms common in modern culture. Somatic Experiencing provides a gentle, titrated way to help individuals safely move through this immobilization and regain a sense of self.
The freeze response is often characterized by numbness, emptiness, and a sense that “nothing is happening.” Paradoxically, it is by allowing these sensations—without fear or force—that the nervous system can begin to reorganize. As awareness remains present with the “no feeling,” sensations and emotions that were previously bound often begin to emerge and complete themselves.
I recall my teacher, Steve Hoskinson, saying to a client who had contacted their frozen state during a Somatic Experiencing session, “What if we just stay with this ‘no feeling’ for a while, without needing to do anything?” As the client brought gentle awareness to the numbness, emotions and sensations gradually arose. This demonstrates that beneath apparent numbness often lies a reservoir of incomplete responses waiting to be integrated.
Regarding the freeze response, Levine states, “The physiological evidence shows that the ability to go into and come out of this neutral response is the key to avoiding the debilitating effects of trauma.” When a traumatized person regains this capacity, it often feels like a new lease on life. A sense of “I can” replaces the pervasive feeling of “I can’t.” Witnessing someone move from listlessness and shutdown to renewed vitality is deeply moving and offers profound hope for healing.
Why, then, do humans struggle to move through these responses as fluidly as animals? One reason lies in the neocortex—the intellectual, rational part of the brain—which often interferes with instinctual discharge. The neocortex tends to analyze, judge, and inhibit bodily impulses, effectively overriding the body’s natural completion of survival responses. Levine describes this as a “self-made web of fear-induced immobility,” in which reasoning substitutes for instinctual action.
Additionally, humans are highly self-conscious social beings. Shaking, trembling, or spontaneous movements following trauma may appear strange or socially unacceptable, so these impulses are suppressed. Over time, this suppression distances us from our instinctual intelligence—the very place where healing resides. Levine emphasizes that healing trauma requires reclaiming our innate capacity to mirror the fluid adaptability of wild animals, allowing the nervous system to pass through immobilization, discharge survival energy, and return to full mobility and aliveness.