Why is trauma, as we know it, a distinctively modern disease? Why do we observe PTSD in domesticated, but not wild, animals?

Trauma is physiological—it’s not just in your head. While it need not involve violence, death, or rape—in fact, it is reliably amplified by boring things like office buildings and public schools—its mechanism includes more than mean people and scary opinions. Let’s start with an example from 9/11: 

“Sharon,” at work in the World Trade Center, felt a shock and an explosion, and tried to run, but found the elevators disabled, and the stairwells already packed. She was forced to walk slowly, with the crowd, down eighty flights, every moment anticipating the next blast, which came as she reached the ground floor. She woke up on top of a corpse. Later she developed a debilitating anxiety, anhedonia, insomnia, and dissociation. 

Don’t let this story’s extremity distract from the details. The secret ingredient of trauma is helplessness. More technically, we are traumatized when our nervous system is mobilized to address a threat, and is in some way thwarted. Here, Sharon’s instinct to run was frustrated, firstly, by the social demands of an organized escape, and secondly, by her being knocked unconscious. 

COMMONPLACE 1: Trauma is fear plus immobilization. 

To understand our first commonplace, you should know a little about the autonomic nervous system. We’re taught in school that this manages unconscious processes such as respiration, perspiration, circulation, etc., and that it mobilizes the body for the “fight or flight” response. So far, so Wikipedia. 

In 1994, Stephen Porges called for an elaboration and revision of our understanding of the autonomic nervous system. In his “polyvagal” model, we have a hierarchy of three autonomic subsystems: smart vagus, sympathetic, and vegetative vagus. 

The middle rung of this “autonomic ladder” will be familiar. The sympathetic-adrenal system mobilizes organs and limbs for a fight or flight response to perceived danger. It is an effective system common to many vertebrates—reptiles, amphibians, fish, etc.—but its activation is metabolically costly. 

The sympathetic system is bracketed by branches of the less-familiar parasympathetic system, distinguishable by their origins in different source nuclei of the brain stem, by the organs each targets, and by function. 

One branch of the vagus nerve originates in the dorsal nucleus and extends its unmyelinated fibers primarily to organs below the diaphragm. This is a primitive system which we share with the likes of this: 

Under life-threatening circumstances, this subsystem may cause the body to immobilize and shut down, in order to conserve energy and to minimize pain. This is sometimes called the “freeze” response. In less oxygen-hungry animals, this can be highly adaptive; in mammals, and particularly in humans, it can be fatal. On account of this function, Porges calls the dorsal vagal complex the “vegetative vagus.” 

At the top of the hierarchy, we have the ventral vagal system, unique to mammals. The myelinated fibers of this “smart vagus” originate in the brain stem’s nucleus ambiguus, and target organs above the diaphragm. This ventral vagal system is also integrated with nerves controlling the throat, middle ear, and the muscles of the face.

For our immediate purposes, we will focus on smart vagus influence on the heart. Porges likens the human heart to a supercharged engine: the sinoatrial node, the heart’s “pacemaker,” independent of vagal influence, sets resting heart rate surprisingly high. This naturally revving engine is habitually inhibited by the smart vagus, a function Porges terms the “vagal brake.” 

Importantly, the brake may be adjusted; the smart vagus may relax its inhibitory control to promote moderate metabolic expenditure. Moreover, the myelination of smart vagus fibers allows such adjustment to take place instantaneously. This means that we can promptly attend to work, to play, or to limited threat without recruiting the sympathetic system, and that we may just as quickly return to a state of calm. 

Because sympathetic fight or flight is metabolically expensive, and dorsal vagal freeze may be damaging, the mammalian preference is to first respond to danger with the smart vagus. If that proves inadequate, the sympathetic system will be recruited before the last resort of dorsal vagal immobilization. Furthermore, the sympathetic and vegetative vagus subsystems are less flexible, in at least two respects. First, the activation of a subordinate system entails the inhibition of superordinate systems. Second, neither the autonomic nor vegetative systems allow for much modulation of response; whereas the smart vagus may promote or inhibit metabolic expenditure, the autonomic is all mobilization, and the vegetative all immobilization. Autonomic and vegetative responses are thus like programs that, once initiated, must be allowed to execute. 

There are grounds to believe that a sympathetic or dorsal vagal activation must be discharged bodily, in the manner observed in a number of species. In this video, you can see an impala captured by a leopard. At the start, it is a completely immobilized rag doll without sign of life. Some time after the leopard abandons its catch, the impala begins to rouse, first breathing rapidly, and before it rises, trembling from head to hoof. This appears to be a mammal’s instinctive, and necessarily physical, means of discharging stress from the body. The stress program is allowed to fully execute, even though the danger is past. Mobilization and immobilization responses must literally be shaken off, or we end up like the traumatized World Trade Center worker with which we began.

Peter Levine believes that we are so much in our heads that we’ve lost, and must relearn, this instinctive stress release. I would add that we have been busily constructing environments—like the World Trade Center—in which it is impossible to execute our fight or flight response. Moreover, what we might call “industrial discipline”—the behavior necessary for the smooth operation of office, classroom, shopping mall, etc.—entails its repression.

The idea that industrialism has a psychological and physiological price is not new. To pave the way for our second commonplace, let’s consider an argument that industrialism has altered our patterns of child-rearing and socialization. 

Towards the end of Freud’s career, he noticed that the typical type of client he was seeing had changed; narcissists were taking the place of the neurotics of his early practice. This shift was significant for more than the treatment of mental illness: in Freud’s view, since inculturation and socialization involve a kind of “character deformation,” (i.e. a focusing, narrowing, or specialization), and since there is a continuity between health and disease, then the lineaments of mental illness reveal those of culture. In other words, mental illness is characteristic of a given civilization; it is a social construction that reveals the pattern of social construction itself. When mental illness changes, it is reasonable to predict changes in socialization. 

By the 40s, sociologists were beginning to notice the same thing. David Riesman’s The Lonely Crowd, published in 1954, claimed that the inner-directed “economic man” of the 19th century had been supplanted by an “other-directed” type bearing a strong resemblance to Freud’s narcissists. Here is his description of the new type:

“What is common to all the other-directed people is that their contemporaries are the source of direction for the individual…The goals toward which the other-directed person strives shift with that guidance: it is only the process of striving itself and the process of paying close attention to the signals from others that remain unaltered throughout life…As against guilt-and-shame controls, though of course these survive, one prime psychological lever of the other-directed person is a diffuse anxiety.”

In three books published in the late 70s and early 80s, Haven in a Heartless World, The Culture of Narcissism, and The Minimal Self, Christopher Lasch built upon Freud and Riesman’s observations, suggesting a cause for the change in character type. The increasing division of labor required by advanced industrialism, Lasch notes, has largely removed instruction and work from the home. When children learn skill and discipline from strangers who do not love them, and are loved by parents who do not teach them, other-direction is the product.

This argument may seem surprising, but it is supported by much clinical observation. Here is a recent (2015) statement of the same point from Bessel van der Kolk:

“A secure attachment [to a parent] combined with the cultivation of competency builds an internal locus of control, the key factor in healthy coping throughout life…Securely attached kids learn the difference between situations they can control and situations where they need help. They learn that they can play an active role when faced with difficult situations. In contrast, children with histories of abuse and neglect learn that their terror, pleading, and crying do not register with their caregiver. Nothing they can do or say stops the beating or brings attention and help.”

COMMONPLACE 2: Affection (secure attachment) and instruction (cultivation of competency), together create an “inner locus of control,” or inner-direction.

The polyvagal model provides a theoretical explanation for clinical observation and Lasch’s thesis. 

We have discussed how the smart vagus regulates supradiaphragmatic organs, and particularly the sinoatrial node of the heart, but mentioned only in passing that this autonomic subsystem is also integrated with nerves controlling the striated muscles of the face, the throat, and middle ear. The smart vagus is the heart-to-head connection, which Porges calls the “social engagement system.” This integration means that humans can intelligibly express autonomic state, and may socially regulate autonomic function, and further, that by practice in social “co-regulation,” we may learn to self-regulate stress. In other words, heart-to-head influence is bidirectional: inner-direction is learned by seeing what others feel, and feeling what you see. 

When he was about two, my son blithely attempted to dive head-first from a tall platform bed. It was only when he observed my expression as I caught him that he became aware of the danger, and began to cry. He felt what he first saw. In this way children learn autonomic regulation from parents’ autonomic expression. 

Secure attachment in the context of child-rearing means that a child has come to trust not only the parent’s autonomic expression, but the parent’s attunement to his own autonomic expression. If a securely attached child learns difficult skills from a parent, he learns not only the skills, but how to self-regulate while performing them, that is, how to marshal metabolic resources by means of the smart vagus and social engagement system. 

As we have seen, when the social engagement system is inadequate to manage a task or threat, we fall back on our more primitive autonomic subsystems, fight, flight, or freeze. Children without secure attachment, having learned that their social engagement system is ineffective and unreliable, must rely on more primitive autonomic fuel. Others may be fortunate to enjoy secure attachment with their parents, but, being instructed largely by strangers, fail to learn performance by means of smart vagus self-regulation, and the result is similar. 

The smart vagus social engagement system is fast, flexible, metabolically cheap, and provides a trustworthy response to social cues. When untrained and impaired, the only alternatives are the relatively slow, rigid, and metabolically expensive sympathetic and dorsal vagal systems. Impairment entails the experience of the social world as hostile or at least inscrutable, and the experience of the self as damaged.

Conviction of social hostility or inscrutability, in turn, leads to hypervigilance of threat, which promotes binary thinking, i.e. reliance upon criteria independent of social intention to determine, at a glance, whether an actor is dangerous. The large metabolic investment of sympathetic arousal inclines those who rely upon it to procrastination or perfectionism, and frequently involves difficulties with sleep and digestion. Autonomic dysregulation, further, may lead to a host of physical ailments, including hypertension, diabetes, and fibromyalgia. These are just a few aspects of the “diffuse anxiety” of which Riesman wrote. 

So much may be said generally. More specifically, we can describe three primary “trauma types”: the autonomically dysregulated will adapt a coping mechanism, or attachment style, corresponding to one of the primitive stress responses, fight, flight, or freeze. 

A fight type approaches the hostile world, and manages his anxiety through domination, accomplished either assertively, by means of grandiosity or bullying, or passively, by means of fawning or manipulation. This “disorganized” attachment style may resemble narcissistic or borderline personality disorder. 

The flight expert attempts to placate the hostile world, seeking safety in busyness and performance. He is the workaholic, the compulsive runner, and the fastidious in charity or religious observance. This “anxious” attachment style recalls obsessive compulsive disorder. 

A freeze type gives up, and loses himself in the dissociation of over-intellectualization or fantasy. He might be a college professor or a drunkard. Sometimes both. His “avoidant” attachment style may resemble autism and ADHD, and may present schizoid features. 

To sum up, we have argued that a change in the typical presentation of mental disease was documented at the turn of the 19th century, indicating a change in socialization and child-rearing. The product of these new patterns of socialization is predominantly other-directed—lacking an “inner locus of control”—with an impaired ability to self-regulate, or manage anxiety. At the same time, industrialism requires habits and environments that preclude the bodily discharge of anxiety. 

The period of the First World War was a watershed in terms of governance and of military, financial, and industrial organization, so perhaps it should not be surprising that it had implications for character formation as well. Our contemporary arrangement may be likened to a factory producing three chief models of trauma robots. Whether this development is regrettable cannot be answered independently of teleology (what are people for?). It has its uses—I have argued that other-direction is the glue of political ideologies and fundamentalist cults, and Lasch thought it the character structure most convenient to totalitarianism, and most susceptible to propaganda—but there is need to remedy its worst maladies. If you would like to read more about the disease and its potential cure, have a look at the following partial bibliography:

Stephen W. Porges, The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation

Stephen W. Porges, Polyvagal Safety: Attachment, Communication, Self-Regulation

Peter Levine, In an Unspoken Voice: How the Body Releases Trauma and Restores Goodness

Iain McGilchrist, The Master and His Emissary: The Divided Brain and the Making of the Western World

Iain McGilchrist, The Matter With Things: Our Brains, Our Delusions, and the Unmaking of the World

Louis A. Sass, The Paradoxes of Delusion: Wittgenstein, Schroeder, and the Schizophrenic Mind

Bessel van der Kolk, The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma

Pete Walker, Complex PTSD: From Surviving to Thriving

Christopher Lasch, Haven in a Heartless World: The Family Besieged

Christopher Lasch, The Culture of Narcissism: American Life in an Age of Diminishing Expectations

Christopher Lasch, The Minimal Self: Psychic Survival in Troubled Times

David Riesman, The Lonely Crowd: A Study of the Changing American Character

Erich Fromm, Escape from Freedom

Jacques Ellul, The Technological Society