Are Trans Women 'Biologically Male'? The Answer is Complicated

This article is reposted from The Conversation.

G. Samantha Rosenthal, Washington and Lee University

A surprising buzzword in the U.S. Congress these days is "biological."

In a now viral video, U.S. Rep. Nancy Mace of South Carolina was filmed taping a piece of paper with the word "biological" on it above a women's restroom sign inside the Capitol building. This followed Mace's introduction of two bills to limit the use of single-sex women's facilities – first in the Capitol then on all federal properties – to members of the corresponding "biological sex."

Mace's Capitol bill claims that the presence of "biological males" in "restrooms, locker rooms, and changing rooms designed for women jeopardizes the safety and dignity" of "female" House members and employees.

What prompted this legislation, as U.S. Rep. Marjorie Taylor Greene of Georgia made clear, is just one person.

"Sarah McBride," Greene told reporters, "is a biological man."

But is she?

McBride, the representative-elect from Delaware, is the first out transgender person elected to Congress.

Neither Mace nor Greene offered any evidence for their claim that McBride is male. In fact, opponents of transgender rights in the United States are not really in agreement on what they even mean by "biological sex."

And the world's scientists aren't either.

As a scholar of transgender history, I have written about the long history of gender-affirming care in the U.S. and the equally long history of backlash against it. Debates over trans rights frequently hinge on a central question about bodies: Is a transgender woman who has medically transformed her body still a "man," or has her biological sex changed?

The answer is complicated.