Early Years: Can We Rewire What Got Wired In?

FND Health
Aug 4
6 min read

I’ve been thinking lately about how our nervous systems might have been wired to overreact — how they became hypersensitive to stress.

To understand that, we have to go back. Back to where it all began.

Because some of us weren’t born into calm. We were born into chaos.

Early Years: Can We Rewire What Got Wired In? — Photo by Annie Spratt on Unsplash

Wired in a World of Chaos

Before we were even born, our nervous systems were already reacting — evolving, adapting, and being shaped by our environment. Long before we had thoughts or language, our bodies were listening. Building a network. Learning what to expect from the world.

And if that early world was full of stress, our systems picked up on it — playing a role in how our nervous system — and even our biology — took shape.

That stress could come in the form of a broken home. Maybe one parent was struggling with addiction. Maybe a sibling was seriously unwell, and the stress in the house was sky-high. Maybe your mum was constantly anxious — not just after you were born, but while you were still in the womb. Stress can take many forms, and there are countless ways we might come into a world already full of it.

And I’m not talking about the everyday ups and downs every family experiences.

I’m talking about prolonged stress — the kind that lingers for years.

The kind that seeps into your system before you even knew what stress was. You felt it all.

Your tiny system was already tuning itself to stress, noise, tension… survival.

We like to think we all start with a blank slate. But the nervous system doesn’t wait until you’re old enough to understand what’s going on. It adapts automatically — wiring itself to the environment it’s in.

And if that environment is full of fear, unpredictability, or emotional absence, then your body learns to live in a state of alert. Even if that chaos became your “normal,” your body might still carry it as dysregulation.

The Science: What Happens in Those Early Years?

The All-or-None Law for Nerves and Muscles (ANS) — the part of your nervous system that regulates things like heart rate, digestion, and stress response — begins developing in the womb and continues rapidly into infancy. It's highly sensitive to environmental input during this window (Frontiers in Psychiatry, 2021).

If that environment is full of stress, the nervous system adapts accordingly — by becoming more reactive, more sensitive to threat. This isn’t a flaw. It’s a survival mechanism. As Jessica Maguire explains, how your parents regulated their own nervous systems — and yours — shapes how you cope with and recover from stress today. These early relationships literally sculpt the vagus nerve and brain regions involved in self-regulation. source - Jessica Maguire

Research also shows that parental stress — even before birth — can affect a child’s development and emotional health (Psychology Today). Chronic early stress (or "early life adversity") has long-lasting effects on circuits in the brain involved in fear, emotion, motivation, and decision-making — especially the prefrontal cortex, hypothalamus, amygdala, and dopamine systems (Journal of Neurodevelopmental Disorders).

This can show up later in life as emotional dysregulation, anxiety, meltdowns, shutdowns — even chronic illness. The nervous system struggles to regulate and may become increasingly prone to getting stuck in survival mode.

The Body Remembers — Even When We Don’t

And here’s the part that many people miss — we don’t have to remember the stress for our bodies to carry it. Research show that chronic or early-life stress can program the autonomic nervous system — particularly the balance between the sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) branches — into a state of heightened reactivity.

This isn’t just psychological stress, and it’s not always linked to a conscious thought like ‘I’m remembering something traumatic.’ Often, there’s no conscious memory at all. The body holds the imprint of past stress in the nervous system itself, below the level of awareness.

Over time, the system learns to default to a ‘threat mode,’ even in safe environments. These reactions happen automatically, via an unconscious process known as neuroception — a term from Polyvagal Theory describing how the body detects danger without involving the thinking brain. Supporting research:

The Impact of Early Life Stress on Growth and Cardiovascular Risk: — PMC5115741
Programming of the stress response: — PubMed 17444884
Early Life Stress, Physiology, and Genetics: — PMC6688564
Neuroception: A Subconscious System for Detecting Threats and Safety — ERICEJ938225

These studies, among many others, show how early biological and emotional stress can become deeply embedded in the wiring of the nervous system — often without our awareness — shaping how we respond to life stressors later on.

So… Can We Rewire What Got Wired In?

This is the question that sits heavy for a lot of us.

If our nervous system was wired for stress, chaos, and survival early on — is it possible to change?

Yes.

That’s the power of neuroplasticity. Our brains and nervous systems are not fixed. They are constantly adapting and changing in response to experience — for better or worse. This means the same system that adapted to survive trauma can also adapt to recover from it.

“The neuroplasticity that enables brains to change in response to trauma also allows them to heal.”— PsychCentral on trauma and EMDR

Therapies like EMDR (Eye Movement Desensitization and Reprocessing) and somatic approaches are now showing that deep healing is possible, even decades after early trauma.

And it doesn’t have to be one big fix. Often, it’s about small, consistent signals of safety sent to the nervous system over time. That’s how rewiring happens — through repeated experience of calm.

Chronic Stress Isn’t Just Mental — It’s Physical

When the stress response is constantly activated, like a motor idling too high for too long, it takes a toll on the body. Elevated cortisol, constant adrenaline — over time, this contributes to everything from anxiety to weight gain, cardiovascular issues, sleep problems, and chronic illness (Harvard Health).

But — and this is key — the body can learn how to put the brakes on.

The same article highlights methods that help engage the body’s relaxation response — the biological opposite of fight-or-flight. These include:

Deep abdominal breathing
Gentle repetition of a calming word (like “safe” or “peace”)
Visualising tranquil scenes
Yoga or tai chi
Mind-body practices like prayer or meditation

These may seem simple, but when practised consistently, they send powerful signals to the brain and body that it’s okay to slow down. That it’s okay to be safe. That we’re not in danger anymore.

Rewiring Is Real. But It’s Gradual.

This isn’t about snapping your fingers and undoing years of survival mode. It’s about slowly shifting your internal baseline. From stress to safety. From hypervigilance to rest. From self-protection to connection.

And it doesn’t just happen in therapy or through mindfulness. It can happen through:

Safe, secure relationships
Healing your gut (which connects to your brain via the vagus nerve)
Getting enough sleep
Gentle movement
Joyful or creative expression
Even play, laughter, or time in nature

Final thoughts

So even if our start in life was full of chaos and stress — when our nervous systems were still developing — and that stress shaped the way we automatically reacted to the world, remember: this wasn’t your fault.

We didn’t know. Our systems were simply doing what they were programmed to do — reacting at a survival level.

And maybe… that’s part of why some of us developed chronic illnesses. When the nervous system gets wired to overreact to stressors, the whole body can end up paying the price.

But here’s the good news: neuroplasticity means we can change what got wired in.

Now, I’m not saying it’s easy.

In fact, it’s often a struggle - Those old tracks still run beneath us, buried just under the surface. When stress hits, the nervous system remembers —slipping back into the grooves.

But we can pause, breathe, and slowly lay down new rails, guiding ourselves toward something steadier —

a new rhythm in the body.

One that feels like calm.

Like safety.

Like joy.

References