Genes Are Not Destiny
How environments — not DNA — shape the minds we become
We’ve been taught that our DNA is destiny.
It isn’t.
The real story is stranger
And far more empowering.
The Illusion of Destiny
In the late 1990s, Judy Singer coined the word neurodiversity and offered a striking image:
“Neurodiversity may be every bit as crucial for the human race as biodiversity is for life in general.”
Just as ecosystems rely on many species, she suggested, humanity relies on many kinds of minds.
It is a powerful idea.
It appeals to virtue.
And it has reshaped public debate for a generation.
Autism, ADHD, dyslexia, and anxiety.
These conditions are now widely framed not as defects.
but as natural variations, written into our genes like eye colour or handedness.
The moral implication is clear: if neurotypes are the natural expression of genetic determinism, then they must be accepted as they are, immutable and beyond discussion.
This framing holds profound consequences.
Over recent decades, the numbers tell a heartfelt story — neurodivergence has soared, with nearly one in three children in some nations carrying a diagnosis.
The ADHD medication market has become a vast, shimmering realm worth billions, echoing a society deeply invested in guiding these life stories.
Research funding flows generously into programs designed not just to help neurodivergent individuals survive, but to help them thrive within the often rigid structures that surround them.
Entire industries have blossomed, born from the tender hope that this surge is both natural and inevitable — a testament to our collective yearning and the intricate tapestry of human diversity.
Which brings us to the hard question: is it?
Is the explosion of neurodivergence simply the unveiling of genetic scripts that were always there, waiting to be recognised?
Or are we witnessing something else entirely — an emergent shift driven by the environments we have created?
The evidence points to the latter.
Cognition is not genetically scripted; it is emergent.
Emergence means that what looks fixed from a distance is, in fact, the outcome of many interacting forces.
Genes matter, but they are not blueprints.
They are raw possibilities, waiting on context.
Which possibilities unfold depends on the interplay of biology and environment.
the stress or safety of the womb, the warmth or neglect of early caregiving, the balance of nutrients and toxins in a child’s diet, the culture and community that shape development.
Neurotypes are not essences handed down by DNA.
They are emergent outcomes, sculpted at the intersection of genes and world, epigenetically shaped and environmentally selected.
This essay traces how we came to mistake genetic determinism for destiny, and what it costs us to hold onto that illusion.
It revisits Darwin, who spoke of traits in context rather than genes in isolation, and shows how his ideas were later miscast into a deterministic frame.
It explores why twin studies and genome scans, so often invoked as proof, fail to demonstrate inevitability.
It introduces the missing middle — the interostate, the body’s inner state of balance and stress — as the true gatekeeper of the reflective mind.
It examines the environmental fingerprints left in pregnancy, in childhood adversity, and even in the food we eat.
And it ends in the Anthropocene
A world we ourselves have reshaped
Where human beings are now the architects
of the very environments that summon minds into being.
The story we have been told is that genes decide who we are.
The story we need to tell instead is that of who we emerge
And that means responsibility lies not in our DNA
But in the worlds we create.
Where did the deterministic story come from?
We have to return to Darwin.
Contrary to how he is often invoked today, Darwin never spoke of genes.
He didn’t even know they existed.
What he described were traits
The curve of a beak,
the colour of plumage,
and the behaviours.
All traits
All helped creatures survive in their environments.
The clue is in the very title of his book:
On the Origin of Species by Means of Natural Selection.
Selection was never about a hidden code.
It was about the environment,
choosing which expressions worked in context.
Darwin was describing traits in relation to their conditions.
a constant dialogue between organism and world.
For most of human history, those contexts barely changed.
Childhood unfolded in remarkably similar conditions.
small groups,
constant movement,
outdoor play,
and storytelling.
And survival was bound to the rhythms of nature.
These environments were relatively invariant
The same developmental outcomes
Reliably selected.
Generation after generation.
When conditions are invariant, traits appear fixed.
Cognitive patterns look hardwired.
Not because they are encoded in DNA.
But because they are selected by environments that scarcely change.
Stability created the illusion of genetic destiny.
It was only with the upheavals of modern life.
industrialisation,
urbanisation,
mass schooling,
processed diets,
Sedentary lifestyle
digital saturation
that the contingency became visible.
As environments shifted,
new patterns of cognition began to emerge.
Traits that once seemed timeless
revealed themselves to be profoundly dependent on context.
This, more than any statistic, explains why determinism took hold.
For millennia, the environment was the silent constant.
Genes looked like fate because their selector never changed.
Genes are not destiny; they are raw material.
Traits emerge in context, and context is never neutral.
But over time, Darwin’s insights were recast through the lens of modern genetics.
With the discovery of DNA, a new metaphor took hold:
The genome as blueprint, the organism as execution.
Darwin was retrofitted as if he had discovered genes before their time
and declared them the sole arbiters of life.
This distortion matters.
It allows us to shrug off the rise of neurodivergence
as if it were nothing more than “genes finally showing themselves.”
But Darwin’s real legacy is more radical:
Survival is always a dialogue between potential and the world.
Change the world.
and new traits — and new neurotypes — inevitably appear.
It is not only diversity in neurotypes that emerges through environmental shifts.
New traits and vulnerabilities are selected whenever the world changes.
Widespread smoking selected for higher rates of lung cancer;
diets devoid of fresh fruit selected for scurvy;
and improved access to protein and nutrients selected for increases in average height.
We looked for causes; we did not celebrate.
We never sang the mantra
It is in my genes.
We have allowed the word diversity to go on holiday.
Instead of naming the specific traits, conditions, or neurotypes
that emerge through environmental pressures,
It has become a catch-all slogan
comfortable to invoke, but too vague to explain.
Diversity is not a backdrop or a virtue in itself;
It is the visible pattern of what environments permit or suppress.
When we speak only of “diversity,” we risk overlooking the harder truth:
It is the contingencies of
nutrition,
stress,
schooling,
and culture
that decide which traits flourish and which wither.
Why Genes Don’t Dictate Neurotype
The illusion of fixity
created by long-term environmental stability
made it easy for later science to read traits as genetically inscribed.
Twin studies and genome scans seemed to confirm the story.
At first glance, both suggest that conditions like autism, ADHD, or dyslexia are “genetic.”
But the closer you look
the less solid the determinist case becomes.
Twin Studies
At first glance,
Twin studies seem to prove that conditions
like autism, ADHD, or dyslexia
are “genetic.”
Identical twins share nearly all their DNA.
Fraternal twins share about half.
When identical twins resemble each other more closely in a given trait,
researchers attribute the difference to genes.
That’s where dramatic claims come from: autism is “80% heritable.”
But heritability is not destiny.
An 80% heritability estimate does not mean autism is “80% genetic.”
It means that in that specific population,
living under those specific environmental conditions,
80% of the variation could be linked to genetic differences.
Change the environment, and heritability changes too.
Height is over 90% heritable
Yet average human height has soared in the past century.
Not because our DNA shifted,
but because nutrition did.
Takeaway: Heritability measures probability, not fate.
Genome-Wide Association Studies (GWAS)
GWAS add another layer of confusion.
They scan DNA across large populations,
looking for variants that show up more often in people with a diagnosis.
The result?
Long lists of “risk/potential genes.”
But polygenic scores explain very little
Usually, less than 20% of the variance.
And even that predictive power
depends on the environment in which the score was derived.
If schooling, nutrition, and culture are broadly uniform,
the only variance left to measure is genetic.
Change the environment,
and the predictive value of the score shifts or collapses.
Many “risk/potential genes”
aren’t fate-writing mutations at all.
They are regulators
exquisitely sensitive to context:
inflammation, synaptic plasticity, stress reactivity.
In one environment,
a variant may tilt toward difficulty.
In another, it may scaffold resilience
or even creativity.
Genes don’t dictate outcomes;
they open possibilities.
Context decides which ones unfold.
The Missing Middle: Emergence and the Interostate
The missing middle
what I call the interostate.
The interostate is the moment-by-moment accumulation
of the body’s internal state
inflammation,
hormones,
nutrition,
stress,
and more.
It acts as a barometer of biological safety,
read by the amygdala,
which signals to the prefrontal cortex
it is safe enough to reflect
or whether survival must take priority.
This inner barometer is the true gatekeeper of the reflective mind.
Twin studies and genome scans
show that genes matter but not that they decide.
What’s missing is the middle layer:
the process by which genetic potential becomes lived reality.
Without this layer, possibility is mistaken for fate.
For much of human history, this middle was hidden.
Stable environments meant the same developmental outcomes
were reliably summoned generation after generation,
creating the illusion of fixity.
Only when modern life destabilised childhood
through new diets, schooling systems, technologies, and stressors
Did the hidden selector become visible.
Emergence
That selector is best understood through the lens of emergence.
Emergence means that what we observe
a neurotype,
a behaviour,
a way of thinking
is not the direct output of genes
but the outcome of many interacting forces.
Just as the flocking of birds emerges from simple local rules,
Consciousness emerges from neurons firing together,
so neurotypes emerge from the dialogue between genes and the world.
At the centre of this process is the interostate
The body’s barometer of biological safety.
The interostate integrates
autonomic tone,
immune signals,
hormonal state,
and emotional load into a single message:
is the world safe enough for reflection, or must we prioritise survival?
In practice, this message is read by the amygdala.
When the interostate signals safety,
the amygdala allows the prefrontal cortex to engage.
Reflection,
inhibition,
curiosity,
and play become possible.
When it signals threat,
the gate closes,
and cognition defaults to reactive modes
of vigilance and defence.
This is the insight of the TGTS model:
thought is not continuously available.
It is gated by the interostate.
And all neurotypes
ADHD, autism, anxiety, and neurotypicality
are selected outcomes of this gating process.
They are not deficits in capacity but equilibria of adaptation:
stable patterns that emerge
when the interostate calibrates itself to the conditions of early life.
To put it plainly:
genes provide possibilities,
but the interostate
as a barometer and selector
decides which possibilities become reality.
Environmental Fingerprints
If neurotypes were written in the genes, the environment would leave no trace.
But everywhere we look,
The fingerprints of the environment are stamped into the mind.
They work by shaping the interostate
tipping the body’s barometer of safety one way or another,
and in doing so, selecting which cognitive equilibrium takes form.
Prenatal Stress: Tatiana and Viktoria
History has given us natural experiments.
Children conceived during famine, war, or disaster
show higher rates of autism and ADHD.
The mechanism is no mystery:
maternal stress hormones cross the placenta, tuning the foetus’s interostate before birth.
Tatiana knew this in her body,
Though she could not name it.
Pregnant when the war broke out,
she lived under sirens and shelling,
her nights broken by fear.
Her body, which should have been a fortress of calm,
became a conduit of stress.
Cortisol surged daily,
and those signals did not stop at her bloodstream
They seeped into the developing nervous system
of her unborn daughter, Viktoria.
Viktoria entered the world already primed for vigilance.
Her interostate had learned danger before it had learned safety.
Reflection was harder to access;
her body defaulted more quickly to defence.
This is what we mean when we say
neurotypes are selected by the interostate:
her genome contained many possibilities,
but the chaos of war
narrowed them toward a profile of vigilance.
Adverse Childhood Experiences: When Vigilance Becomes Biology
The same dynamic plays out after birth.
The landmark CDC–Kaiser study
of more than 17,000 adults found a relentless gradient:
each additional Adverse Childhood Experience (ACE) —
neglect,
abuse,
parental addiction,
domestic violence
increased the likelihood of later difficulties
in attention,
emotion,
and mental health.
Behind the numbers are children
whose interostates adapt the only way they can.
A boy who flinches at every slammed door.
A girl who scans each room before speaking.
Their amygdalas learn to read the world as unsafe.
The interostate locks into high arousal.
The gate to reflection narrows.
What looks like impulsivity or inattention is not a broken brain
But the biology of defence
An equilibrium selected by chronic threat.
This is autonomic inflexibility:
once a system that could flex between stress and calm,
it becomes rigid,
canalised by adversity into a single survival mode.
The ACE is not just a memory.
It is an environmental fingerprint
pressed into the body’s barometer of safety.
Diet and the Microbiome: Daniel’s Story
The environment inscribes itself even more deeply — in the gut.
Ultra-processed foods (UPFs),
erode the microbiome.
They starve the trillions of microbes
that help
regulate immunity,
mood,
and cognition.
Daniel, seven years old, ate little besides UPFs.
His microbial diversity collapsed.
Inflammatory signals rose.
His interostate tilted toward sympathetic arousal,
stuck in “fight or flight.”
The gate to reflection narrowed.
His restlessness and anxiety
Not mysteries of genetic wiring
but echoes of a diet dismantling microbial ecosystems.
Here lies the proof:
A child’s microbiome can shift within days of dietary change
And behaviour often shifts with it.
Genes do not change in days.
The interostate does.
The Lesson
Maternal stress,
childhood adversity,
processed diets:
each leaves fingerprints on the interostate,
tilting the balance of safety and stress.
And with each tilt, a different neurotype is selected.
Neurotypes are not immutable codes written into DNA.
They are emergent outcomes of bodies adapting to their environments.
Genes open possibilities;
the interostate chooses which to realise.
Responsibility in the Anthropocene
The determinist story has lulled us into passivity.
High heritability estimates
long lists of “risk genes”
make it sound as if outcomes were written in advance.
But the evidence says otherwise.
What determines cognition is not DNA
but the interostate —
the body’s barometer of safety,
the gatekeeper of reflection.
Genes provide possibilities.
Environments decide which ones take shape.
For most of human history,
Stability made genes look like destiny.
But in the Anthropocene,
Stability has shattered.
Screens saturate childhood,
ultra-processed diets inflame the body,
schooling collides with sensitive windows of development,
And chronic stress erodes safety.
Our DNA hasn’t changed in a few generations
But the selector has.
And that places the responsibility with us.
The philosopher Sartre once wrote that
“existence precedes essence”.
Biology makes the same point:
Who we are is not given, but emerges.
The question is no longer
What do the genes decide?
They decide nothing alone.
The real question is:
What kinds of minds do we, as a society, want to call into being?
.
The lesson is stark.
Neurotypes are not immutable identities delivered by genes.
They are equilibria, selected by environments.
And in this new epoch, environments are of our own making.
That gives us responsibility.
The landscapes we build —
nutritional,
digital,
educational,
emotional —
will decide the kinds of minds that flourish.
The question is no longer
What do the genes decide?
They decide nothing alone.
The real question is:
What kinds of minds do we, as a society, want to call into being?