What happens in our bodies during a traumatic event? Why do some people develop lasting trauma while others don’t?
In his groundbreaking book Waking the Tiger, trauma expert Peter Levine explores what causes trauma through the lens of our natural stress responses. He reveals that trauma stems not from permanent damage but from incomplete physiological responses to threatening events.
Keep reading to discover how our bodies naturally process trauma and why humans often interrupt this vital healing mechanism.
What Causes Trauma
Levine shares his perspective on what causes trauma, arguing that trauma isn’t the result of irreversible damage to any part of a person’s body or mind. Rather, a person suffers from chronic trauma symptoms because their body hasn’t completed its physiological stress response to the original traumatic event.
(Shortform note: Although Levine says that trauma doesn’t result from irreversible physical damage, evidence indicates that direct physiological wounding is a primary cause of some trauma cases. For instance, researchers have found that some US veterans’ PTSD symptoms are the result of microscopic scars in the brain created by nearby explosions.)
Levine explains that, when threatened, animals (and humans) generate a burst of stress energy and instinctively choose from three possible responses: fight, flight, or freeze. The freeze response—the most relevant to human trauma—serves as a last-ditch survival mechanism, allowing prey animals to play dead and potentially escape when a predator’s guard is down. It also induces a dissociative state where pain is not experienced, sparing the animal from needless suffering as it’s being eaten. This frozen yet high-stress state is temporary—animals naturally unload excess stress energy after a threatening event, often shaking or trembling to get it out of their system.
| Fight, Flight, Freeze, or Fawn When discussing an animal’s possible stress responses, many experts also include the “fawn” stress response: when a threatened animal acts submissive to pacify an aggressor. Unlike the other trauma responses that animals can quickly shake off (as Levine explains), it’s common for animals to develop a habitual long-term fawn response. For example, a rescue dog might act overly submissive if it’s been mistreated by a past owner. Traumatized people sometimes habitually resort to the fawn response, too. For instance, a child might act unusually eager to please to try and keep their abusive parent happy and calm. |
Humans Interfere With Their “Freeze” Response
According to Levine, humans (like animals) enter a “freeze” state in response to highly stressful events. However, unlike animals, humans resist and suppress their natural stress recovery response. The process of exiting the freeze response and releasing trapped energy typically involves intense physical sensations, including trembling, shaking, and sweating. These sensations are often frightening or uncomfortable, so people attempt to suppress them. Humans’ highly developed neocortex allows them to do so, shutting down the stress recovery response (which occurs in more primitive parts of the brain) before it reaches its natural conclusion.
Levine explains that, when humans suppress their stress response, a vicious cycle begins: They become frozen in this trauma-response state, leaving them trapped in a state of constant stress. The persistent feelings of anxiety and fear that accompany this state further drive them to suppress their stress response. Over time, this stress energy continues to build, manifesting as trauma symptoms.
| This Explanation Currently Lacks Evidence This understanding of the neuroscience of trauma currently isn’t completely backed by evidence from researchers. It’s true that humans enter a “freeze” state in response to threatening situations, and many clinicians observe neurogenic tremors (intense trembling) in trauma victims. However, there isn’t strong evidence that the neocortex interferes with the primitive brain’s stress recovery response by suppressing unpleasant sensations. It’s true that some areas of the neocortex can create constant stress and anxiety when hyperactive. For instance, the dorsal anterior cingulate cortex helps evaluate potential threats and trigger reactions of fear, so when it’s hyperactive (as it is in people with PTSD), people more easily become panicked and stressed. However, other areas of the neocortex cause people with PTSD to suffer because those areas aren’t active enough. For example, the ventromedial prefrontal cortex monitors and prevents inappropriate fear reactions. So, when it’s not working properly, people (again) become panicked and stressed more easily. That said, evidence shows that people who use Levine’s healing method often successfully heal from trauma. For this reason, it may be helpful to believe that this view of the brain and stress energy is at least true in a metaphorical sense, if not a literal one. |
