“What doesn’t kill you makes you stronger.”
It is one of those phrases that sounds encouraging and supportive—until we go through something genuinely difficult and realise that we do not feel stronger at all.
We may feel more frightened. More vulnerable. More exhausted. We may startle more easily, find it harder to trust, remain constantly on alert, or feel that our body cannot fully relax.
And then the same phrase can carry a second, much harsher message:
“If what I went through did not make me stronger, is there something wrong with me?”
Current research on stress, trauma, and resilience invites us to look at this differently.
Trauma is not training
We often imagine stress as a form of exercise. Just as a muscle grows stronger when we gradually increase the weight placed on it, we may assume that every difficult experience adds another “weight”, and that if we endure enough of them, we will eventually become stronger.
Our bodies do have a remarkable capacity for adaptation. When we face a threat or an intense challenge, the body mobilises: alertness increases, heart rate changes, stress hormones are released, and energy is directed towards whatever we need to deal with. This adaptation is essential for survival.
The difficulty begins when there is not enough time between stressful or demanding experiences for the body to return to a state of relative calm. When stress is continuous or repeated, the body has to adapt again and again. Bruce McEwen described the cumulative cost of this ongoing adaptation using the term allostatic load (McEwen, 2004).
The body can withstand stress. But the continuous effort of adapting to it has a cost.
Research suggests that people exposed to multiple adverse experiences, particularly during childhood, may later show a greater overall physiological burden of stress (Guidi et al., 2021). This does not mean that trauma inevitably leads to mental health problems, or that everyone responds in the same way. It does suggest that repeated exposure to stressful conditions can influence the way the body responds to and regulates stress.
So the process is not necessarily:
stress → adaptation → greater strength.
Often, it may be closer to:
stress → adaptation → survival → cost → need for recovery.
The nervous system does not only learn to endure. It also learns to protect.
After intense or repeated traumatic experiences, our nervous system may become more sensitive to signs of danger. If someone has learned that danger can appear suddenly, it may be more adaptive for the brain to respond occasionally to something that turns out not to be threatening than to miss a genuine threat.
After traumatic experiences, a person may therefore notice a persistent need to stay watchful, heightened reactivity, difficulty feeling safe, or strong responses to cues that recall, even indirectly, an earlier danger.
In other words, the brain can become highly attuned to scanning the environment for what might go wrong.
This does not mean that everyone who experiences a traumatic event will develop post-traumatic stress. People follow very different paths after trauma, and many recover without developing a chronic disorder (Bonanno, 2004).
There is no single “neurological fate” after trauma. There is vulnerability, there is adaptation, there is resilience, and there is the possibility of recovery.
After severe stress, the way different brain systems interact may also change. This may mean that someone responds more quickly to potential danger or finds it harder to reduce the intensity of their response once a perceived threat has passed (Roeckner et al., 2021).
These changes do not necessarily mean that the brain has been permanently damaged. The brain remains capable of change and adaptation. Through new experiences, supportive relationships, and the development of different ways of regulating ourselves, people can gradually develop new expectations about what is dangerous and what is safe.
Traumatic experiences may influence the way the brain and nervous system respond to the world. But this does not mean that the past determines how they will function forever.
It is not that we became weaker
Someone who grew up in an unpredictable environment may have learned to register changes in another person’s tone of voice almost immediately. To notice a small withdrawal. To catch a shift in someone’s gaze. To anticipate other people’s moods. Never to relax completely.
At one time, this may have been extremely useful.
But danger does not follow every time someone’s expression or mood changes.
Not every change in another person’s behaviour signals a threat. And when we have learned to constantly search for signs of danger, we may eventually find it difficult to distinguish intuition from fear, and a real threat from the expectation of one.
This is why, in psychotherapy, it is not enough simply to learn to endure more.
We may need to learn once again to distinguish:
- When is there real danger, and when is there safety?
- When do I need to stay alert, and when can I let go?
- When is my body responding to what is happening now, and when is it responding to something that happened long ago?
This is not weakness.
It is relearning safety.
Resilience does not mean you were unaffected
Another difficulty with the idea that “what doesn’t kill you makes you stronger” is that it creates a misleading picture of resilience—as though there were two categories of people: those who broke and those who grew stronger.
Research does not describe resilience so simply.
Resilience may mean that someone was deeply affected but gradually managed to recover. It may mean that they experienced significant symptoms for a period of time and later regained their functioning. It may also mean that, despite the difficulties, protective factors—such as supportive relationships, social support, a sense of meaning, or the capacity to regulate emotions—helped support adaptation (Bonanno, 2004; Southwick et al., 2014).
In other words, resilience does not necessarily mean:
“It did not affect me.”
It may mean:
“It touched me. It changed me. And gradually, I found a way to live again.”
You do not have to find the good in the trauma
In recent years, the concept of post-traumatic growth has become increasingly well known: the idea that some people report positive changes following a traumatic experience.
And this does happen. Some people, after a difficult experience, report a greater appreciation of life, different priorities, deeper relationships, or a new sense of personal strength.
But there is an important distinction.
The fact that some people experience growth following trauma does not mean that the trauma was necessary for them to grow. Nor does it mean that someone who does not feel stronger has failed to process the trauma properly.
Research on post-traumatic growth also has important limitations. People may report that they feel they have changed or grown, without all of those perceived changes necessarily reflecting objective psychological improvement (Boals, 2023).
This does not invalidate post-traumatic growth. It simply invites us to understand it more carefully.
Learning to return to safety
After a traumatic experience, or after a prolonged period of psychological strain, we may need to learn how to return to a sense of safety.
Very often, thoughts like these arise:
- “Why haven’t I got over it?”
- “Why am I still afraid?”
- “Why am I not stronger after everything?”
- “Other people went through worse and managed.”
Here, self-criticism can become a second layer on top of the original trauma.
There is no longer only what happened. There is also the way we speak to ourselves about what happened—and about how we believe we “should” be afterwards.
This internal attack is not necessarily neutral for our nervous system. Research has linked self-criticism with neural systems involved in threat processing and negative self-evaluation (Longe et al., 2010).
The way we speak to ourselves may influence how we experience threat and stress. This matters particularly after traumatic experiences, when our protective systems may already be on heightened alert.
The role of self-compassion
Self-compassion is often misunderstood.
“If I go easy on myself, won’t I simply be letting myself off?”
“If I do not push myself, how will I move forward?”
“Shouldn’t I be stronger than this?”
But self-compassion does not mean telling ourselves that everything is fine, or excusing every choice or action.
It means being able to acknowledge pain without adding shame and self-attack on top of it.
It means being able to say:
- “That was very difficult for me.”
- “It makes sense that my body responds this way after what I went through.”
- “I do not have to prove that I am strong by suffering more.”
- “I can understand what happened to me without blaming myself for it.”
In one experimental study, a brief self-compassion intervention appeared to reduce certain subjective and physiological responses to social evaluative stress (Arch et al., 2014).
Findings such as these suggest that the way we relate to ourselves may influence how we experience stress.
What strength may actually look like
Real strength after trauma may have less to do with enduring more and more pain, and more to do with learning again to recognise what we need and to relate to ourselves and others differently.
To recognise hypervigilance.
To notice when our body is on alert.
To distinguish the past from the present.
To ask for help.
To allow someone to come close without automatically expecting to be hurt.
To discover, gradually, that calm does not necessarily mean that something bad is about to happen.
Strength is not the capacity to endure more and more pain.
It may be the capacity to live without constantly having to protect ourselves.
And perhaps this is why, after trauma, the most important question may not be:
“How do I become stronger?”
But rather:
“How can I feel safe enough again that I do not have to be strong all the time?”
Because healing is not always about increasing our tolerance for pain.
Sometimes, it is about learning that we no longer have to live inside it.
References
Arch, J. J., Brown, K. W., Dean, D. J., Landy, L. N., Brown, K. D., & Laudenslager, M. L. (2014). Self-compassion training modulates alpha-amylase, heart rate variability, and subjective responses to social evaluative threat in women. Psychoneuroendocrinology, 42, 49–58. https://doi.org/10.1016/j.psyneuen.2013.12.018
Boals, A. (2023). Illusory posttraumatic growth is common, but genuine posttraumatic growth is rare. Clinical Psychology Review, 99, 102230.
Bonanno, G. A. (2004). Loss, trauma, and human resilience: Have we underestimated the human capacity to thrive after extremely aversive events? American Psychologist, 59(1), 20–28. https://doi.org/10.1037/0003-066X.59.1.20
Guidi, J., Lucente, M., Sonino, N., & Fava, G. A. (2021). Allostatic load and its impact on health: A systematic review. Psychotherapy and Psychosomatics, 90(1), 11–27. https://doi.org/10.1159/000510696
Longe, O., Maratos, F. A., Gilbert, P., Evans, G., Volker, F., Rockliff, H., & Rippon, G. (2010). Having a word with yourself: Neural correlates of self-criticism and self-reassurance. NeuroImage, 49(2), 1849–1856. https://doi.org/10.1016/j.neuroimage.2009.09.019
McEwen, B. S. (2004). Protection and damage from acute and chronic stress: Allostasis and allostatic overload and relevance to the pathophysiology of psychiatric disorders. Annals of the New York Academy of Sciences, 1032(1), 1–7. https://doi.org/10.1196/annals.1315.001
Roeckner, A. R., Oliver, K. I., Lebois, L. A. M., van Rooij, S. J. H., & Stevens, J. S. (2021). Neural contributors to trauma resilience: A review of longitudinal neuroimaging studies. Translational Psychiatry, 11, 508. https://doi.org/10.1038/s41398-021-01633-y
Southwick, S. M., Bonanno, G. A., Masten, A. S., Panter-Brick, C., & Yehuda, R. (2014). Resilience definitions, theory, and challenges: Interdisciplinary perspectives. European Journal of Psychotraumatology, 5(1), 25338. https://doi.org/10.3402/ejpt.v5.25338
