When is gender identity set? What the science actually says

What I actually said, and why I need to correct the record

On the Trigonometry programme, in a conversation with Kellie-Jay Keen, I said: "Your gender identity is set at birth, um, or, or even b- from conception. We don't know." I want to address that directly, because the first clause of that sentence goes further than the science warrants, and the hesitation in how I said it reflects the fact that I was already reaching the edge of what I could confidently claim.

The position is that the second part, "we don't know," is the most accurate thing I said. I should have let that carry more weight than it did. Saying gender identity is set at birth or conception overstates what the current scientific consensus supports, and I would rather correct that clearly than let an imprecise live remark stand as my position.

What the research actually shows

There is genuinely interesting research pointing to prenatal influences on gender identity. Studies have looked at hormonal exposure in the womb, genetic factors, and neurological differences, and some of that work is suggestive. It points in a direction. But pointing in a direction is not the same as a settled finding, and the difference matters.

The biology of gender identity is complex, and it does not reduce neatly to a single moment or mechanism. Researchers are looking at a range of overlapping factors: prenatal hormone levels, receptor sensitivity, gene expression, and the interplay between all of these. What the evidence does not yet support is the specific claim that gender identity is fixed at a single identifiable point, whether conception, birth, or any other.

The most accurate summary of where the science stands is this: there are biological influences, their nature and timing are not fully understood, and this is an active area of ongoing research. That is a less tidy answer than "set at conception," but it is the honest one.

Why this matters, and why it also does not

I understand why questions about the origin of gender identity carry so much weight in public debate. For some people, the idea that gender identity has a biological basis feels like it confers legitimacy, as though trans people need a prenatal origin story to justify being who they are. I want to gently push back on that framing, because it sets a standard we do not apply to anything else about a person's identity, personality, or inner life.

We do not require a genetic explanation for someone's sense of humour, their faith, their experience of falling in love, or their feeling of belonging to a particular culture. We accept those as real because people experience them and live by them. Gender identity is no different in that respect.

At the same time, I do think the biological research is worth taking seriously, not because trans people need it to be real, but because it helps us understand human development more fully. If prenatal hormone exposure influences gender identity in some people, that is scientifically interesting and has implications for how we understand a wide range of human variation. The research deserves to be reported accurately, which means neither dismissing it nor overstating what it has found.

The problem with overclaiming in either direction

One thing I have noticed in public debate about trans issues is that both sides often overclaim about the science. Some people insist that biology definitively explains trans identity and that gender identity is fixed from conception. Others insist that gender identity is entirely socially constructed with no biological component whatsoever. Neither position reflects where the research actually sits.

The truth is more interesting and more open than either of those positions allows. Human development is not a simple story of genes producing fixed outcomes. It involves ongoing interaction between biological factors, developmental environment, and lived experience. Gender identity, like many aspects of who we are, probably reflects something of all of those, in proportions we do not yet fully understand.

That complexity is not a weakness in the case for trans people's existence and rights. It is just the reality of being human.

What I stand by, and what I would say differently now

I stand by the substance of what I was trying to say in that conversation: that gender identity has real, likely biological components, and that trans people are not making a choice or performing an identity. The evidence genuinely points in that direction. What I would say differently is this: we do not yet know the precise biological mechanisms, and we should not claim more certainty than the research gives us.

The most defensible position, and the one I should have articulated more cleanly, is that gender identity appears to have biological roots, the nature of those roots is still being worked out, and that uncertainty does not make trans identity any less real or any less deserving of respect and affirmation.

Honesty about uncertainty is not a concession

Some people will read a correction like this and treat it as a concession, as though admitting scientific uncertainty undermines the case for trans people's validity. It does not. Science that is honest about what it does not yet know is more trustworthy, not less, and a trans person's identity does not depend on research having answered every question about its origins.

People have always existed across the full range of gender. That is documented across cultures, across history, across every society we have records of. The research into biological origins is trying to understand a phenomenon that has always been part of human life. Its conclusions so far are suggestive, genuinely interesting, and still incomplete, and saying so plainly is the only honest position available to anyone who takes the science seriously.