Introduction
The most useful sentence a person can learn about their own nervous system is this: my reactions make sense. Not “my reactions are good”, and not “my reactions are fine as they are” — just that they make sense. They are the coherent output of a system that learned, through experience, how to keep this specific person safe. What looks like an overreaction from the outside is almost always a proportional reaction to something the outside cannot see.
Why This Matters
The alternative story — “I am broken; my reactions are random; I should be able to override them” — is the most reliably corrosive story a person can carry. It fights the very system it is trying to change. Understanding that reactions make sense changes what we do with them, and that changes almost everything.
The Science
Polyvagal theory (Porges, 2007, 2011) describes the nervous system as running a continuous, non-conscious appraisal of the environment for cues of safety, danger, and life-threat — a process he named neuroception. That appraisal draws on the individual’s history: what a body has learned is dangerous, it will treat as dangerous again, often faster than conscious thought can catch up. The reaction is not proportional to the current stimulus. It is proportional to the pattern the stimulus resembles.
Work on adverse childhood experiences (Felitti et al., 1998; Nelson et al., 2020) documented how early exposure to stress calibrates stress-response systems for the long run — a calibration that is adaptive in the environment that produced it and often less adaptive in later ones. Teicher and colleagues (2016) mapped concrete structural and connectivity changes in the brains of people with histories of adversity, showing that the reactive templates are held in tissue, not merely in memory.
Current Research
Contemporary trauma-informed research treats “overreaction” as a category error. What is being called overreaction is usually the correct output of an under-updated model: the world has changed, but the model of the world still expects the old danger. Kolacz, Kovacic, and Porges (2019) extend the polyvagal framework into the autonomic gut-brain axis, showing how early stress leaves durable signatures in physiological reactivity that persist even after the stressor is gone.
Practical Implications
The next time a reaction embarrasses you, try a different first question. Not “why did I do that?” but “what did my nervous system just recognise?” The answer is often visible within a breath or two: a tone, a facial expression, a spatial configuration, an implied threat. The reaction is the alarm; the alarm makes sense; the useful work is updating what the alarm is set to.
Common Misconceptions
**“If my reactions made sense, I wouldn’t regret them.”** Making sense and being welcome are different questions. A reaction can be a coherent output of a well-calibrated old system and still be one you would like to update.
**“Making sense of reactions is just excusing them.”** Understanding a reaction and choosing what to do with it are separate steps. The first is not the second; but the second is much harder without the first.
Key Takeaways
- Reactions are outputs of a nervous system running its learned safety programme.
- What looks like overreaction is usually a proportional response to something invisible to observers.
- Neuroception (Porges) runs beneath conscious thought and draws on personal history.
- Understanding a reaction is the prerequisite for updating it, not an excuse for it.