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Biological Sex
Also written: Biological sex, Biological male, Biological female, Biological man, Biological woman, Biological gender
evolving-usagepoliticized-term
At a glance
Source-by-source
“Use "assigned female/male at birth" or "sex assigned at birth." Avoid "natal sex," "biologically female/male," or "born a woman/man."”
As the earliest entry on the page (2017), Radical Copyeditor sets the replacement the later guides inherit — "assigned sex at birth" — and notably rejects "born a woman/man" alongside the "biological" forms, closing off the verb-phrase workaround, not just the adjective.
2023 · entry updated 2021-03-01 VERIFIED-ARCHIVED
“Avoid the terms "biological gender," "biological sex," "biological woman," "biological female," "biological man," or "biological male." These terms are inaccurate and often offensive… Instead use: assigned male/female at birth, assigned sex at birth or raised as a boy/girl.”
The Diversity Style Guide advises against the full family of "biological" sex-and-gender phrases as inaccurate and often offensive, pointing instead to "assigned male/female at birth" and asking writers to weigh whether the story needs birth-assignment information at all.
“In reference to gender, do not use terms such as biological truth or biological sex… Do not use phrases such as biological male to refer to transgender girls and women or biological female to refer to transgender boys and men.”
NLGJA tells journalists not to use "biological sex," "biological truth," or "biological male/female," noting opponents of trans legal protections deploy them as political branding that oversimplifies the many factors determining sex, and to fact-check any quotation that contains them.
2026 · entry updated 2025-09-24 VERIFIED-ARCHIVED
“The phrase biological sex is common in scientific writing as a synonym for birth sex, natal sex, or assigned sex at birth. Outside of medical literature, assigned sex at birth is preferable over biological sex if used in this way.”
TJA treats "biological sex" as a phrase to handle with care rather than ban outright: in scientific and legal writing it functions as a synonym for assigned sex at birth and sometimes must be quoted directly and contextualized, but outside medical literature "assigned sex at birth" is preferable, and the politicized colloquial use that implies a fixed, binary "real" sex should be avoided.
Audience notes
- Journalists and editors
- Outside of quoted scientific or legal language, prefer "assigned sex at birth" (AFAB/AMAB), and first ask whether birth-assignment information is relevant to the story at all. When a law or quotation uses "biological sex," quote it directly, explain how that source defines it, and add context — including that it can mean different things in different policies.
- "Biological man/woman" is the harder line
- The corpus rejects "biological male/female" and "biological man/woman" near-universally, especially when applied to trans people. "Biological sex" as a clinical synonym has narrow, contextualized uses; the personal labels do not.
- Advocates and internal comms
- Treat "biological sex" as politicized framing when it surfaces in opposition messaging — sources describe it as a branding tool used to imply a person's "real" sex is fixed and binary. Self-identification is primary; lead with how a person identifies.
Synthesis
The corpus agrees that “biological sex” is an oversimplified, politically loaded framing and that “assigned sex at birth” is the replacement, but it splits on how absolute the avoidance should be. Radical Copyeditor (2017), the Diversity Style Guide (entry updated March 2021), and NLGJA (2025) treat the phrase as one to avoid. Radical Copyeditor and the Diversity Style Guide route writers to “assigned female/male at birth” or “sex assigned at birth,” and the Diversity Style Guide adds that the whole “biological” family (“biological woman,” “biological male,” and so on) is “inaccurate and often offensive.” NLGJA sharpens the political reading: it describes “biological sex” and “biological truth” as terms opponents of trans legal protections use as branding tools that oversimplify the many factors determining sex, and tells journalists to fact-check any quotation that relies on them.
The Trans Journalists Association (entry updated 2025-09-24) draws the one distinction in the set. TJA separates the clinical use of “biological sex,” a synonym for assigned sex at birth that appears in scientific writing and in laws that must sometimes be quoted directly, from the colloquial use that implies a person’s “real” sex is unchangeable, binary, and set at birth. Its guidance is to prefer “assigned sex at birth” outside medical literature, and, when covering policy, to quote the legal language, explain how that source defines “biological sex,” and add context. The phrase “biological man/woman,” by contrast, is rejected across the sources with little qualification.
The takeaway is consistent: prefer “assigned sex at birth” (AFAB/AMAB) when birth-assignment information is genuinely relevant, and first ask whether it is, with self-identification as the primary frame. “Biological sex” survives only as quoted or clearly contextualized scientific or legal language; the personal labels “biological male/female” and “biological man/woman” do not. This page pairs with gender identity, the concept the sources keep distinct from sex.
History note
The sources track a roughly chronological move from a plain “avoid this phrase” rule toward a more layered reading. The earlier entries (Radical Copyeditor 2017; Diversity Style Guide, entry updated March 2021) frame “biological sex” mainly as a phrase to replace with assignment-at-birth language. The later entries (NLGJA 2025; TJA, entry updated 2025-09-24) add the reading of the phrase as politicized branding and, in TJA’s case, the legal and policy-coverage point about quoting and contextualizing it where it appears in law.
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