Transsexual women are considered to be a third gender rather than proper women.

1. How major institutions define trans women: women, not a third category

Contemporary public‑health and advocacy sources define transgender women as women whose assigned sex at birth was male but who identify and live as women; older clinical labels like "transsexual" describe a medical subset but do not create a distinct social category called a "third gender" in these institutions’ frameworks ^{[1] [7] [2]}. Planned Parenthood and national LGBTQ resources explain that gender identity is an internal sense of being a man, woman, or another gender, and that many transgender people simply identify within the binary as women or men rather than as a separate category ^{[8] [3]}.

2. Why some scholars and cultures talk about third genders

Across cultures and within some academic literature, terms like travesti, hijra, Two‑Spirit, or genderqueer are treated as identities that may function as a "third gender" or non‑binary role distinct from binary trans women, and historical classification schemes noted many different subtypes of gender variance ^{[4] [9]}. Wikipedia’s coverage emphasizes that "transgender" is an umbrella term that can include non‑binary people and culturally specific third‑gender roles alongside binary trans men and trans women, which explains why the label "third gender" appears in cross‑cultural discussions ^[4].

3. Biology and brains: neither simple nor decisive

Neuroimaging studies cited in the provided reporting find that brain‑structure measures in transgender women are often shifted toward their gender identity but still distinct from both cisgender male and female averages, producing intermediate patterns rather than a categorical "third brain sex," which speaks to biological complexity rather than to a clean social classification ^{[5] [6]}. Such findings are used by multiple sides in debates—some argue they validate trans identities as rooted in biology, others caution that brain‑imaging does not map neatly onto social categories and cannot alone settle normative questions about gender ^{[6] [5]}.

4. Evolving terminology and political stakes

Language has shifted from "transsexual" and "male‑to‑female" to "trans woman" and "transgender," reflecting both clinical changes and political preferences; this linguistic evolution matters because who gets to name a group influences legal protections, social inclusion, and access to care ^{[4] [7]}. Activist groups like GLAAD and the APA advocate for recognizing trans women as women and warn that treating them as a separate category often underlies exclusionary politics; conversely, "gender‑critical" thinkers argue from concerns about sex‑based protections and sometimes promote treating trans women as distinct—an argument framed and contested in philosophy and law ^{[2] [10]}.

5. Synthesis: social classification versus lived identity

The clearest factual synthesis from the reporting is that most contemporary medical, advocacy and legal frameworks classify trans women as women and do not treat trans women generally as a separate "third gender," while anthropological and some scholarly work recognizes cultures and identities that are functionally third‑gender or non‑binary—so both realities coexist depending on the frame being used ^{[1] [4] [3]}. Scientific nuance about brain structure complicates reductionist claims on either side ^{[5] [6]}, and terminology remains politically freighted: whether someone is called a "woman" or a "third gender" can reflect clinical definitions, cultural context, or a speaker’s ideological stance ^{[4] [10]}.