# Psychological Trauma and Its Evolutionary Nature - URL: https://alisanburak.com/en/ruhsal-travmanin-evrimsel-dogasi - Language: en - Last updated: 2026-08-29 - Page title: Psychological Trauma and Its Evolutionary Nature | Assoc. Prof. Dr. Alişan Burak Yaşar > Why do PTSD symptoms exist? What do the amygdala, hyperarousal, and avoidance as a defensive strategy tell us from an evolutionary perspective? This page was translated automatically from Turkish. [Read the original](https://alisanburak.com/ruhsal-travmanin-evrimsel-dogasi) [← Back to blog](https://alisanburak.com/en/blog) # Psychological Trauma and Its Evolutionary Nature December 24, 2018Articles in Bilim ve Ütopya [Görsel: Psychological Trauma and Its Evolutionary Nature] I discussed the symptoms, nature, and future of psychological trauma in detail in my previous article, “Travma terapileri, iyileştirim ve sağkalım” (Trauma Therapies, Healing, and Survival), published on the Bilim ve Ütopya web portal [1]. Now I will discuss perspectives on the evolutionary nature of psychological trauma symptoms, which I mentioned in that article as a subject for a separate piece. For this article, I drew primarily on the chapter on psychological trauma in Martin Brune’s book on evolutionary psychiatry, Evrimsel Psikiyatri ve Psikosomatik Tıp (Evolutionary Psychiatry and Psychosomatic Medicine). I recommend it to interested readers as an introduction to this perspective [2]. As you may recall, psychological trauma arises after an event that is genuinely distressing or perceived as such. It involves symptoms such as negative thoughts that occupy the mind even when a person does not want to think about them, emotional turmoil, fleeing or avoiding places where one would normally feel comfortable, and being easily startled or aroused [3]. Psychological trauma most commonly leads to depression and, most characteristically, to post-traumatic stress disorder (PTSD) [4]. To draw an example from another system in our bodies, excessive accumulation of nonfunctional antibodies can sometimes lead to a systemic problem and allergic reactions, as we know [5]. Similarly, after stressful events, our psychological system can make life difficult to bear for someone who has experienced psychological trauma through symptoms of depression or PTSD [6]. As psychiatrists and psychotherapists, we can alleviate these symptoms using scientifically validated methods. But why might our bodies, which produce antibodies when microbes enter, produce depression under stress? We now know quite a lot about which parts of the brain become more or less active after psychological trauma. Broadly speaking, in people who have experienced psychological trauma, the alarm region called the “amygdala” continues to sound the alarm (remains highly active) even years after the trauma. Before trauma therapy, the amygdala, particularly its right side, is highly active, while Broca’s area, which is involved in speech, is less active. After treatment, however, the brain’s alarm region calms down, and painful experiences become possible to talk about. Broca’s area, associated with speech, recovers and functions adequately again [7]. Of course, what actually happens is somewhat more complex than this account suggests. Nevertheless, all the symptoms, emotions, and thoughts that people experience after psychological trauma are, in fact, ordinary components of a mechanism operating through structures in the human body that are there to become active when needed. These symptoms involve critical systems that have been with us for as long as we have existed. So what function might be served when this mechanism, firmly established in humans for tens of thousands of years, sometimes remains in a state of alarm? PTSD can, in fact, be seen as a combination of various defensive strategies. It involves a range of defenses organized in successive stages. When we consider trauma symptoms, these defenses include hypervigilance, avoidance of situations that may be associated with risk, immobility accompanied by heightened attention, withdrawal, aggressive defense, and freezing. We can also conceptualize these strategies, all of which evolved in our vertebrate ancestors millions of years ago, as ancient survival mechanisms. Indeed, various publications report that PTSD also occurs in primates—that is, in other mammals—whose young are separated from their mothers early, who live in isolation in small cages, or who experience trauma following repeated sedation for medical research [2]. In other words, trauma symptoms appear to exist in nonhuman animals as well. However, the defensive mechanisms involved in PTSD are not specific to PTSD. These features also occur in anxiety disorders, depression, and obsessive-compulsive disorder [2]. Viewed in this light, psychological trauma plays an important role in most mental disorders, and even in other physical illnesses, as many scientists now propose and demonstrate [8]. It can trigger the emergence of an underlying illness, worsen an existing illness, or directly cause these conditions to develop. Treatments for psychological trauma also make important contributions to recovery from other illnesses [9]. Let that be the focus of another article. The heightened attention and constant state of alarm we observe in people who have experienced psychological trauma may help them detect potential dangers. Thus, wakefulness, loss of sleep, and being easily startled may primarily serve a “preparatory function,” keeping the organism alert to danger [2]. From an ethological perspective, careful observation of the environment may have evolved to avoid devastating threats. Species living under a constant threat of predation may adapt, and chronic predatory threat does not lead to functional changes in the stress response system. Chronic stress and the organism’s response to it are more likely to arise in species with long life histories. Short-lived species such as field mice do not show signs of chronic stress. Conversely, the human organism’s response to stress and trauma may be a defense that works against danger in the short term but becomes ineffective or even harmful when it becomes chronic. If we divide the mind into three parts—the most primitive, the intermediate, and the most developed—we can identify the frontal lobe as the part that makes us human. Avoidance is a relatively primitive response of the mind’s primitive regions, conserving energy by avoiding combat [7]. Avoidance is a preventive response that occurs before an attack, whether real or imagined [2]. If avoidance fails and the threat of an encounter is approaching or unavoidable, attentive immobility may occur. This state of alertness involves attention, a slowing of the heart rate, reduced pain sensation, and a startle response. Attentive immobility or freezing (a state of shock) prepares the organism to choose among different courses of action, including withdrawal, flight, aggressive defense, or relaxation. Withdrawal and flight resemble avoidance, but there is now a perceived threat. Aggressive defense involves fighting when anger takes over. The frequent complaints of low frustration tolerance, irritability, and angry outbursts in patients with PTSD can be viewed in this light [2]. Another strategy, partial submission—as if negotiating with the aggressor—is a partially resistant response to an ongoing threat. We can also think of it as a pause in the fight against the source of the threat, namely the perpetrator causing harm. This occurs when it is impossible to escape a dominant aggressor. As a defense against the harmful experiences we have endured, our minds may therefore make us more vulnerable and susceptible to similar experiences again, perhaps in an attempt to overcome them this time. This is an automatic response of our organism, yet people who have experienced trauma find themselves stuck in the past, continually blaming themselves for what they did or did not do. In fact, rather than being a conscious choice, this is simply one of the defensive systems inherent in psychological trauma and the human organism [2]. Tonic immobility (remaining rigid and motionless) is a last resort that occurs when a devastating threat is imminent. It may involve the muscles, but it can also be understood as a freezing of the mind or emotions. When we examine this phenomenon, we broadly refer to its most pronounced form in psychiatry as “dissociation.” Human PTSD research has found freezing and immobility to be more common among survivors of sexual assault than among other people [2]. Furthermore, as researchers demonstrated while developing the new psychotherapy approach known as Somatic Experiencing, feigning death—a motionless, disconnected, frozen state—is an important survival strategy in nature [10]. Taken together, these observations suggest that people experiencing PTSD-related symptoms exhibit excessive defensive responses after life-threatening events, feel internalized helplessness and terror very intensely, and seek ways to avoid future retraumatization. Thus, one possible mechanism explaining both the development of PTSD signs and symptoms over time (symptoms may sometimes emerge late) and their persistence may be an effort to preserve autonomy and gain control over potential threats, even though many people with PTSD fail to achieve this. Interestingly, if we view traditional cultures as model societies for our ancestors’ “environments of evolutionary adaptedness,” we can see that PTSD is not rare, but its symptoms appear less severe. In some societies, substantial numbers of people are killed through homicide (approximately 30 percent of the Ache people and 4 percent of children among the Kung San) or warfare (25 percent of Melanesian men in New Guinea). Given the prevalence of assault and violence in these cultures, PTSD has been reported among the Kung San, but avoidance behavior has been less prominent among the symptoms observed in these societies. In other words, some systems in this repertoire of defensive strategies appear to be less active in certain circumstances. Being able to grieve and participate in mourning rituals may prevent many people from developing more severe post-traumatic symptoms. These insights from traditional cultures may shed light on practices for coping with trauma in our own culture. A lack of social support after a traumatic event leads to ongoing stress and the PTSD syndrome. For example, someone who has experienced psychological trauma may develop much more severe symptoms if those around them respond with blame and devaluation. In summary, PTSD is a heterogeneous condition characterized by both ancient and more recently evolved defensive mechanisms against life-threatening events. Some PTSD-related symptoms can also appear sporadically across many different mental disorders. In severe cases, they can cause functional impairment [2]. Thinking about this account through a brief story may help us bring it together as a coherent whole. Imagine a community living in a forest 10,000 years ago. If a lion attacked this community and injured a child, let us consider the psychological symptoms that might arise among this group of people living in ancient times. What would typically happen after such an event? People would mistake even cats for lions, have nightmares for days, lose sleep, startle at the slightest sound, and find themselves thinking negative thoughts about the lion even when they did not want to. Some would even develop depression. The group would also repeatedly recount the event to others, who would become traumatized through hearing about it. Being easily startled, fleeing, and avoiding would drain their energy as an exaggerated alarm and warning signal. Yet their chances of survival would increase, at least in the short term. An alarm system that is easily activated by danger, and of course often sounds when there is none, would be unable to remain silent when real danger arrived, and the group would be preparing for it. In earlier times, when the internet, books, and systematized cultures were not nearly so developed, these symptoms may indeed have played a very important role in our species’ survival. Yet they may not be so essential for humans today. Looking again at the present, trauma symptoms also impair people’s ability to analyze long-term circumstances and find solutions; flight, avoidance, and flashback symptoms prevent us from acquiring new knowledge that could help us avoid danger. This is why we recommend psychotherapy to people experiencing psychological distress. At the same time, when I consider nature, now left defenseless against our species, I cannot help thinking that perhaps nature itself needs to experience trauma symptoms and some degree of flight, avoidance, and anger. Thus, for humanity, which has acquired power over the world that escapes control, we may be living in a critical century for analyzing the nature and meaning of psychological trauma and developing an active philosophy concerning life and the existence and sustainability of the world. ## References 1. www.bilimveutopya.com.tr/makale/travma-terapileri-iyilestirim-ve-sagkalim 2. Brüne M. Textbook of evolutionary psychiatry and psychosomatic medicine: The origins of psychopathology. Oxford University Press; 2015. 3. Kessler RC, Rubinow DR, Holmes C, Abelson JM, Zhao S. The epidemiology of DSM-III-R bipolar I disorder in a general population survey. Psychol Med. Cambridge Univ Press; 1997;27(05):1079–89. 4. Tural Ü, Önder E, Aker T. Effect of depression on recovery from PTSD. Community Ment Health J. Springer; 2012;48(2):161–6. 5. Dannaeus A, Inganäs M. A follow‐up study of children with food allergy. Clinical course in relation to serum IgE‐and IgG‐antibody levels to milk, egg and fish. Clin Exp Allergy. Wiley Online Library; 1981;11(6):533–9. 6. Hammen C. Stress and depression. Annu Rev Clin Psychol. Annual Reviews; 2005;1:293–319. 7. Van der Kolk B. The body keeps the score. Viking New York; 2014. 8. Felitti VJ, Anda RF, Nordenberg D, Williamson DF, Spitz AM, Edwards V, et al. Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults: The Adverse Childhood Experiences (ACE) Study. Am J Prev Med. Elsevier; 1998;14(4):245–58. 9. Foa EB, Keane TM, Friedman MJ, Cohen JA. Effective treatments for PTSD: practice guidelines from the International Society for Traumatic Stress Studies. Guilford Press; 2008. 10. Payne P, Levine PA, Crane-Godreau MA. Somatic experiencing: using interoception and proprioception as core elements of trauma therapy. Front Psychol. Frontiers; 2015;6:93. --- *This article was first published on the web portal of Bilim ve Ütopya magazine on December 24, 2018. Since the portal has been taken offline, I am republishing the text here.* [← Previous Trauma Therapies, Recovery, and Survival](https://alisanburak.com/en/travma-terapileri-iyilestirim-ve-sagkalim)[Next → Groups and Social Interaction 1: “Tell me your friend's strengths, and I will tell you yours”](https://alisanburak.com/en/gruplar-ve-sosyal-etkilesim-1-arkadasinin-guclu-yanlari) --- Kaynak / Source: https://alisanburak.com/en/ruhsal-travmanin-evrimsel-dogasi İletişim / Contact: Bağdat Caddesi, Veli Güneysu Apt. No:453 K:4 D:9, Suadiye / Kadıköy, İstanbul · +90 532 642 95 25 · info@alisanburak.com · https://alisanburak.com/bagdat-caddesi-psikoterapi-iletisim