How to tell if someone was born male or female?

Is there a sure-fire method of identifying a person’s born gender based solely on physical appearance?

Some argue that there is a way comparing finger measurements, some say all males have Adam’s apples, and the list goes on. I just want to get to the bottom of this one, if at all possible.


No, because gender isn’t binary.

Because of the way you asked the question, I think this is the only factual answer you can get.

In order to get a more nuanced answer, I think you’d need to define “sure-fire” as being x% sure, and specify that you are referring to sex, not gender.

No, there is no surefire method to determine “born gender” solely through appearances. Actually, since there are a small percentage of XY females and XX males in the population even chromosomal testing is not 100% reliable.

Especially since the advent of plastic surgery, appearance alone is even less reliable.

Well, even if you define “born gender” as the chromosomal configuration, then there are possibilities other than XX and XY. There’s also X, XYY, XXY, XXYY, XXXXY, XXX, XXXX, XXXXX, and of course mosaics of any two or more of the preceding.

I can say for sure that the finger-length thing isn’t absolute. When we learned about it in biology class in my (all-male) high school, we checked and found that one of the guys had “feminine” hands. Nobody ever really doubted his masculinity, but we did make fun of him a bit for it.

The Adam’s Apple is also not absolute, being just the degree of prominence of the larynx. Some males lack very prominent laryngeal bulges, and some women may have them. This is far from a sure indicator of sex.

The parlor trick with the wall and the chair would probably weed out almost all ADULT men if we’re not dealing with true hermaphrodites, and assuming a test population of men and women with normal skeletal structures , but then you would have some women with joint issues who may not be able to pass it either. Plus this isn’t really an appearance based test, you have to do something, and a biological man living as a woman is not likely to cooperate.

As has been mentioned before, gender specific traits occur on a spectrum, and are not an either-or categorical factor. Furthermore, how does one really define being male or female? Is it by genitalia? Secondary sex characteristics? Genotype? Reproductive capability? Is a woman who has undergone gender reassignment surgery male? Is a person who is genotypically XY but who also has androgen insensitivity a woman? What about people who suffer from trauma at an early age that alters their genitals and their parents put them on hormone therapy? What about a woman who is infertile because of some childhood infection? There are many grey areas.

Can you explain this test?

Surely the best way is to check for a penis or vagina? Sure it’s still not going to be perfect, but it’ll be better than finger lengths.

You are aware of sex change surgery, right? A penis can be removed and replaced by a vagina and vice versa.

What about checking for internal organs, like ovaries or a prostate? I suppose their absence wouldn’t confirm anything since they can be removed, but their presence should be a pretty sure indicator, right?

Yes but it’s relatively rare. More rare than things like female finger lengths appearing in men. It just seems to me that the best physical indicator is the genitals, if you want something more accurate than that then you need to look at more than just physical appearance.

I had to look this up, too, having no clue what the poster was on about. Apparently, it’s this.

I assume “fall” is “wall.” I’m having a little difficulty imagining what is supposed to take place.

OK, apparently this is a Youtube video of it.

edit: I’m a male and, if I’m doing it right, it’s not a problem for me. By “if I’m doing it right,” I’m not sure if I’m supposed to be about two footlengths from the wall, or three footlengths from the wall (as measured by distance of wall to toe). If it’s two, then I can do it easily. If it’s three, I can’t, but neither can my girlfriend.

It’s three

OK, well either way, I guess it doesn’t work for one of us. (I was confused about the foot lengths issue as the Snopes article describes two footlengths [wall to toe, NOT wall to heel], and other sites have people disagreeing whether it’s two or three.)

Nope, you can’t tell if someone is xx or xy from their looks (although the physical markers of being just x or x-partial-x [Turner’s syndrome] are pretty noticeable in most cases). Hormones influence every aspect of someone’s appearance and people regardless of whether they are technically male or female can have masculine, feminine, or ambiguous appearance due to this influence before their birth, or from recent hormonal treatment. And with modern surgery +hormonal therapy, someone born the opposite sex can easily appear more feminine/masculine than the average person.

If you haven’t heard of androgen insensitivity syndrome, you should look it up. The people with the most extreme manifestation of the disorder are born with a Y choromosone, technically fully male, but since they are unable to ‘recieve the message’ of the male hormones in their body, they develop physically as unusually feminine women - from bone structure and facial features to great skin, lush head hair, almost no body hair, hourglass figures. Usually no one knows they have the condition until they fail to menstruate (they have internal testicles, no female reproductive organs, vaginal isn’t shaped normally).

Incomplete AIS is the most common cause of ambiguous gentalia at birth.

I knew a former FBI agent, and he says that they were taught to look for a brow ridge. Men have them, women don’t. Usually.