There are few processes more intricate, more fragile, and more quietly astonishing than how a child becomes themselves.
We often imagine development as a staircase — simple steps upward from helplessness to autonomy. But those who have truly studied its depths — from Aristotle to contemporary scientists — know that development is not linear. It is a symphony of interactions, echoes, and contingencies. Nowhere is this more vividly felt than in the unfolding debates around ontogenetic development and the nature of epigenesis.
To understand the child, we must first understand how life begins not just physically, but relationally.
Epigenesis: The Unfolding of Potential
The term epigenesis dates back to Aristotle, who observed that the embryo does not begin as a miniature human, fully formed and waiting to expand. Instead, it becomes — cell by cell, structure by structure — through a process. Development is not the playing out of a script already written. It is the writing of the script in real time.
This perspective has always stood in contrast to preformationism, the belief that all traits, all structure, even all generations, are nested like dolls inside one another from the start. In that older worldview, development is just a matter of time — unrolling what already exists.
But epigenesis tells a different story. It says: what exists now is not what will be. The child is not a revelation. The child is a creation.
The Misleading Comfort of Certainty
It’s easy to understand why preformationism was attractive. It offered predictability. It made life mechanical, measurable, controllable. It whispered that the essence of a person — their traits, temperament, talents — was preloaded, perhaps even preordained.
For centuries, this belief coexisted with scientific curiosity. Even as microscopes began to reveal the raw, pulsing structures of early life, many clung to the idea of hidden blueprints inside sperm or egg, each generation waiting quietly inside the previous one. There was something deeply comforting, if not truthful, in believing that life was already solved.
But Caspar Friedrich Wolff’s careful studies in the 18th century cracked this illusion. He watched chick embryos form not from pre-made parts, but from fluid sheets that folded, curled, transformed. It was not emergence from within. It was construction.
He offered a revolutionary image: that life, at its core, is formed by interaction.
Epigenesis Today: Not Just Biology, But Relationship
Modern developmental science, as presented in The Cambridge Encyclopedia of Child Development, builds upon this legacy. It refines our understanding of epigenesis — not just as biological change, but as a system of coactions.
Genes do not operate in isolation. The environment is not just a background. Development happens because organism and environment respond to each other.
Think of it this way: a child is not molded by nature or nurture. They are sculpted by the conversation between the two.
Gilbert Gottlieb, one of the great voices in this field, described this as probabilistic epigenesis. He argued against the neat, one-directional view that genes lead to structure, and structure leads to behavior. Instead, he proposed a dynamic model — one where experience can shape gene expression, and behavior can influence biology.
In this light, development becomes a web of influence. Not a path, but a dance.
Beyond the Nature–Nurture Debate
Much of the 20th century was consumed by a false war: nature versus nurture. Are we born with our traits, or shaped by the world?
The very question misunderstands the child.
A child does not receive traits like hand-me-down clothes. A child generates outcomes through their active engagement with the world. Even the most basic capacities — walking, speaking, forming attachments — do not emerge without experience. And those experiences are not added onto a passive brain; they are woven into its very architecture.
Genes set possibilities. But it is the act of living — the reaching, the feeling, the being seen — that determines what becomes real.
This is not ideology. It is biology made humble.
Why This Matters
To understand epigenetic development is to relinquish the dream of certainty. We do not know, at birth, who a child will be. And that is the sacred nature of development.
It is a process that must be nourished, not managed.
It means our role — as parents, teachers, caregivers, societies — is not to control outcomes, but to create conditions. Conditions of safety, curiosity, connection. Conditions where the child can engage, and through that engagement, become.
We do not build children. We support them as they build themselves.
Becoming Human
When we trace the debates over epigenesis — from the philosophers of antiquity to the neuroscientists of today — we are not just tracking intellectual history. We are witnessing a shift in how we see life.
From certainty to emergence.
From inheritance to interaction.
From blueprint to dialogue.
A child is not a repetition. A child is a new act of creation, shaped moment by moment through contact with the world.
And perhaps that is the most hopeful thing science has to offer us: the reminder that who we are is not fixed. That development is not done. That the work of becoming never ends.