Nature vs Nurture - What We Pass On Before Birth
Introduction
I’ve been in health and sports medicine for over 50 years, and I never stop asking questions. Much of what I write here is playful speculation, drawing on decades of study, observation, and inquiry. It is not medical advice — just food for thought.
Please take a few minutes to read this:
The baby is listening
From the moment of conception, the baby is not a silent passenger. It is listening to signals from its mother, asking:
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Is the environment safe and welcoming, or is it hostile?
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Will there be plenty of food, or will there be famine?
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Which parts of my Godscript — my genetic code — should I turn up, and which should I turn down?
If the mother feels secure and content, genes that support calm parasympathetic growth may be upregulated. If she is anxious, stressed, or unhappy, genes that prime the sympathetic nervous system (fight-or-flight) may be strengthened.
If nutrition is abundant, the foetus may favour lean tissue and energy-burning. But if food is scarce — or if the mother is a picky eater, undernourished, or over-exercising — the foetus may dial down metabolism and up fat storage, preparing for deprivation. Biology is clever like that. The baby is constantly tuning its Godscript to match what it “expects” in the world outside the womb.
Godscript: nature’s blueprint
At conception, half the Godscript comes from the father and half from the mother. This sacred script is shared across all life. It holds the notes for growth, repair, and resilience.
But having the score isn’t enough. You still need instruments and a conductor. Genes may be the music, but the quality of the performance depends on the environment in which they are read.
The womb as conductor
The intrauterine environment decides how the Godscript is played. Through the placenta, the baby inherits:
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Nutrients — folate, iodine, amino acids, fatty acids, vitamins
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Toxins — pesticides, plastics, heavy metals
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Hormones — cortisol, oestrogen, thyroid, progesterone
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Immune signals, stress chemicals, and sometimes medications or drugs
Every one of these factors can flip genetic switches on or off. This is why so much of what we call “genetic” is really inherited in broader ways — through nutrients, toxins, stress, and epigenetics.
The mitochondrial monopoly
Here’s something most people overlook: all mitochondria come from the mother. The father’s sperm mitochondria are destroyed after fertilisation. These little powerhouses fuel every cell, regulate energy, immunity, and repair, and sit at the heart of performance and ageing.
Please read these articles about mitochondria:
If the mitochondria are faulty, the Godscript cannot be properly read, no matter how good the code. Even the best sheet music sounds poor if the instruments are broken. This makes maternal health, fitness, and mitochondrial resilience absolutely central to a child’s long-term health.
The father’s role
The father’s contribution goes beyond half the nuclear Godscript. His sperm carries:
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Epigenetic markings that affect gene expression
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Small RNAs that guide early development
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Age-related mutations — older fathers pass on more de novo changes
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Lifestyle imprints — from stress, smoking, alcohol, or toxins
So while the mother’s role dominates during gestation, the father’s condition at conception still leaves a lasting mark.
Genetics vs inheritance
This is why I distinguish between genetics and inheritance. Genetics is simply the DNA code — the Godscript. Inheritance is broader: everything passed from parents to child, including mitochondria, nutrients, toxins, stress, and even the exposures of grandparents via epigenetics.
It helps explain why conditions like autism, obesity, and other modern health challenges can rise so sharply in just one or two generations, and why the Mother's side of the health history equation is ,more revealing and helpful than that of the father. Our Godscript hasn’t changed that fast. But what babies inherit through the womb has, let alone what happens after birth.
Putting it together
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Father: half the Godscript, plus sperm quality, age, and exposures.
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Mother: half the Godscript, all mitochondria, and the entire womb environment, including her state of nutrition, toxicities and state of mind.
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Child: the outcome depends on how the Godscript is read and played in the womb, and how well the mitochondria keep the instruments in tune.
A Freeranger conclusion
When people debate “nature versus nurture,” they miss the point. The two are intertwined from the start, and are inseparable. The Godscript sets the score, but it is the quality of the womb environment and the mitochondria that determine whether the music soars or stumbles.
Our greatest inheritance is not money or property — it’s health. We pass this on through what we eat, how we live, the stress we carry, and the resilience of our mitochondria.
That, I suggest, is the legacy that matters most.
Be strong!
Be healthy!
Be freerange!
