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“It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn't feel like a giant. I felt very, very small.” – Neil Armstrong (1930-2012)

Fresh Reads from the Science 'o sphere!

Sunday, April 20, 2008

Counterintuitive Science: The Ultimate Woman Is A Man

Just watched an old episode of House M.D. entitled "Skin Deep" last night, and it was about a bizarre condition that totally blows common sense out of the water.

The patient, Alex, is a uber hot teenage supermodel babe, the physical epitome of feminine beauty. She was suffering from a number of weird symptoms, such as double vision, sudden aggression, short-term memory loss and muscle spasms.

After a few wrong turns, Dr. House makes an astonishing diagnosis.

The young lady has cancer - in her left testicle.


It turns out that Alex has complete androgen insensitivity syndrome or CAIS (inaccurately called "male pseudohermaphroditism" in the show) - an uncommon (but by no means rare) condition that has an incidence of approximately 1 in 20,000 live births.

This means that genetically speaking, she has XY sex chromosomes - like a man.

Unlike ordinary men though, mutations in the androgen receptor gene in her genome (in the X-chromosome) has caused all the cells in her body to be insensitive to the male hormone testosterone. Thus, during embryonic development, male primary sexual characteristics do not develop. A penis does not form and the testes remain in the abdomen instead of descending into the scrotum.

However, the testes are still producing Mullerian inhibiting hormone (MIH), which inhibits the complete development of the uterus, fallopian tubes and cervix.

As such, individuals with CAIS have female physical characteristics, but have no periods and are infertile.

The incredible consequence of total androgen insensitivity is that CAIS women are likely to appear more sexually attractive due to enhanced female features such as a lush head of hair, long legs, well-developed breasts and clear skin.

In contrast, XX women are actually quite sensitive to testosterone (also produced directly and indirectly by the ovaries and adrenal glands) which plays a secondary role during their physical and behavioural development from infancy through puberty.

Thus, a XY woman may appear more "womanly" than a XX woman, leading Dr. House to quip that "the ultimate woman is a man."

Despite the inaccuracies and over-dramatization (the depiction of a CAIS woman and House's callous treatment of her in this episode drew the ire of a specialist in the field), I think this show highlights some interesting questions about sex and gender identity.

Does genetics determine your gender identity? Is gender something that fits into two distinct categories, or more of a continuum along a spectrum?

When a XY man falls in love with a XY woman (easy to imagine why), is he a homosexual?

If you're a guy, and the love of your life turns out to be a XY woman...

Will you stop loving her?

Would you like to know more?
- About
Androgen Insensitivity Syndrome
- Original research article about AIS:
Differential gene-expression patterns in genital fibroblasts of normal males and 46,XY females with androgen insensitivity syndrome (Holterhus et al. 2003)
- About the actress who played Alex: Cameron Richardson


Anonymous said...

One of the best books, in my opinion, on this subject is Sexing the Body by Anne Fausto-Sterling. She discusses the biology of sex and the social history of constructing it.

To answer your questions, sex is not a dichotomy... and neither is sexuality.

Anonymous said...

Your blog is getting so interesting I hope you don't start charging subscription fees! LOL

Your blog is like the adult version of science mags I used to subscribe to when I was in primary school.

FB supporter

Lim Leng Hiong said...

To Mybackstage:

Welcome to Fresh Brainz! Yes, at the individual level, sex and sexuality are not dichotomies. However, at the societal level, dichotomies (even false dichotomies) are of immense social power.

Thanks for pointing out Dr. Fausto-Sterling's book; interested readers can check out a primer of her book here:

To FB supporter:

Should I start charging a subscription? Hmm... ;)

Edgar said...

I watched that episode with much amusement but didn't follow up to read what the real condition was called, thanks for enlightening me. I went away thinking that pseudofemalehemaphroditism thing was real. Kinda freaky its so common.

the real cmf said...

"Will you stop loving her?"
Hawhawhaw....sounds like the menopause dilemma;-)
Or as I like to say "men 'l pause" when they see those hot flashes coming on...

Or what most guys go through when they discover *gasp* that the clitoris has a mind of its own, not much different than a penis;-)

Anonymous said...

You said: the societal level, dichotomies (even false dichotomies) are of immense social power.

As a sociological social psychologist, I would have to agree with you 100%!

Lim Leng Hiong said...

To Edgar:

You're welcome, I thought Dr. House sounded quite authoritative too: to be sure, "pseudohermaphroditism" isn't totally wrong but it's an inaccurate and out of date terminology.

I think the incidence of intersex conditions remind us that embryo development is a physical process that can result in very variable outcomes. Too many people believe that it is some kind of magic or miracle.

To The Real CMF:

I would go further and argue that any organ potentially has a mind of its own, not just sex organs.

But that's an article for another time... :P

To Mybackstage:

Of course, that's because it's 100% true. Is the sky blue? Heh heh...

Anonymous said...

Androgen insensitivity syndrome is actually a specific type of male pseudohermaphrodism. The definition of pseudohermaphrodism is a condition in which a person's "gonads and sex chromosomes are discordant with secondary sex characteristics, which include the genital tract and external genitalia. Genetic males (46,XY) with feminized genitals are called male pseudohermaphrodites and genetic females (46,XX) with virilized genitals are called female pseudohermaphrodites" (Larsen's human embryology 2009). So while they are not being as specific as they could be, the general term of male pseudohermaphrodism is correct.

Jaime said...

Really interesting topic...

It's really hard to me, to imagine the immense social, and psychological stress this disorder may cause.

Sex, as all of you said, is not a dichotomy, but it depends what sense we are talking in.

Biologically, both, male and female, at the beginning, are the same structure, but due the genetic programming, our cells take one of two possible pathways... inhibiting one, and stimulating the other...
The clitoris, is the equivalent to the male pennis, since the sexual differentiation modifies it.

When I think about it, I ask myself... "So, our sexual attraction/behavior (heterosexuallity or homosexuallity) is learnt from the social rules and environment? or is genetically given to us?

If the last, why this "girl" with CAIS is attracted to boys? since "she" has a XY cromosomes in his/her cells?

Before i studied this disorder, I believed that the sexual behavior was genetically given to everyone.

Now, I doubt, I mean, I cannot say I'm sure, either I disagree with it, simply... I doubt, I don't know what to think.

But, maybe... it's best not to understand all the things now, and simply recognize that some things, are, still, beyond our understanding.


Angelae said...

In regards Jaime's question "...If the last, why this "girl" with CAIS is attracted to boys? since "she" has a XY cromosomes in his/her cells?"

I looked into this question.

Wikipedia has an extensive article on CAIS, and under the subheading Management, said this: "Individuals with CAIS are raised as females [1]. They are born phenotypically female and almost always have a heterosexual female gender identity [39][61]; the incidence of homosexuality in women with CAIS is thought to be less than unaffected women [62]".

This basically says that these XY folks are almost ALWAYS attracted to men. This strongly suggests that hormones and their capacity to be assimilated into the cells are the primary determinants of sexual orientation, not the effect of the "Y" chromosome alone. In those people that have normal androgen sensitivity (what we would call normal men) the rate of homosexual attraction is much lower, perhaps the rule-of-thumb 10-15%

By extension, this may shed light on male-to-male attraction as a developmental issue caused by hormonal imbalance or deficiency, improper release or timing, sensitivity at the cell receptor sites (there is a condition called PAIS-Partial Androgen Insensitivity Syndrome) or the amount of saturation in utero.

What I'm suggesting is that the default state for a human is primarily female in body, mind, and in behavior i.e. sexual attraction, until the differentiating effects of testosterone are completed. For many folks, they don't completely transition from a female (in utero) platform to a completely developed male, keeping the default sexual attraction of females towards males.

So perhaps what we call homosexuality is really a male body that didn't complete the switch at the brain level from a default female platform. I'm working on this idea...

Angelae Le'Chastaignier

Anonymous said...

"When a XY man falls in love with a XY woman (easy to imagine why), is he a homosexual?"

Not sure, I also don't see why it be easy to imagine, I would say if he had no idea before about the condition then no he's not a homosexual because of that. Now what he decides after he knows is open for debate

"If you're a guy, and the love of your life turns out to be a XY woman...
Will you stop loving her?"

For me that answer would be yes, it may be shallow but I know for a fact if my girlfriend reveled that to me I would not only stop loving them, but if they knew before hand and didn't disclose I would be angry. I'm not to keen on people deciding things for me on a personal level

Mari24 said...

Hi! I've got CAIS, and the question whether you'll continue loving a girl with CAIS or not if or when she reveals it, really bothers me.. Should this really be an adressed problem at all? isn't it the person you're in love with, and not their cromosomes? A woman with CAIS is in fact that, a woman. To use me as an example, There's nothing about me resembling what to be typically male, neither mind nor body. Not a single thing, except the XY-cromosomes.. (I've taken out the "testes", wich in reality are more like ovaries, except they don't produce eggs)

But the fact that many men/boys (and girls) are so narrowminded when it comes to this (I can understand why), make me never wanna tell the complete truth about my condition to my boyfriend, at least not before I know he really loves me, because I know how it may sound, and what he would think.. that I'm partially a boy..

But that's wrong. Yes, the ultimate woman is a man (but only through the cromosomes).. I've got big round-shaped breasts with tiny nipples, no pubic- or armpit-hair, never had any acne(?), almost no body-odeur, no periods, I'm slim, got a "vase"-shaped body. I've been with a few men, and they just LOVE my body. On the contrary, I can never bare children, nor have a child that is biologically mine, and that's the only, but a huge negative thing about my condition.

NO wonder this condition has always been/still is/will continue to be a huge tabu.. and it's just because of the narrowmindness of people not having it, because they got little or no understanding of it. I don't blame you! So please don't blame me, or any other CAIS woman, for not telling the whole truth to our boyfriends.

I've told my boyfriend I can't have children, but that it is because i had cancer in my ovaries as a teenager. I know it's wrong to lie, but in this case I think it's morally right.

PS: i'm norwegian, so there might be some mis-spellings and gramatically wrong sentences, but I hope you understand. If there's any questions to what i've written whether it's because of the language or the content, don't hesitate to ask ;D

issa jakes said...

for you all but especially Mari. a poem:

the seed

swimming in an
ocean of pettiness
both word & deed
his shell worn thin by the juggernaut
of poltroon drudgery
he imagines himself instead
the mansized organs of a woman
his arms and legs the folds of vulva
labia majora walnut cream
minora fading pink
darkening & swollen
his mind the glittering clitoris
& thought it's reaching to emerge
his heart deeply rooted
is her cervix & as he glides the sheath comforts
the clear innocent mucus
& the os opens to kiss his ideas
passing & teeming within his own womb
gushing up fallopian tubes cilia propelling
to find the egg making its way
receptive & nuzzling it now
to start this thing again as a gesture
whose intention is to sew everywhere
the seed of joy.

the word sex, etymologically, means division. in this light, all things are sexual by degrees. this is how we know the world. we all have our deviations that make us lovely to some, repulsive to others. we 'fall in love' long before we know the integrity of our lovers, if we ever will, for the gesture of life brooks no end of openings. love's destiny is to grow. the person who truncates it due to fear has truly authored a tragedy. if i loved you Mari it would be as much because of your chromosomes as it would your outward appearance as well as a host of other elements continually emerging as you become evermore yourSelf. loving you would be a daily leap of faith, as it is with anyone, that you would be excited to embrace what emerges in me too.

if, when you tell your boyfriend what you know now about youSelf, he leaves, it will be more than a loss for him. it will be the beginning of the end of his ability to genuinely engage the joy of life. once we begin letting fear primarily direct our decisions it is hard to turn back and do anything truly authentic and loving.

Anonymous said...


I am a girl with CAIS, it was found as a toddler and i have spent the rest of my life dealing with it medicaly and mentaly.

Even though i have an incredibly supportive family, in the back of my mind i have always felt completly diffrent to every one else, and have found telling the 100% truth about my condition has resulted in some very embarasing and scaring situations all because of ignorence. This has left me with a lack of trust and a real complex! I have no problem sexually and in a long term relationship with an understanding partner so i am very lucky but i spent the majority of my life thinking i was too diffrent and no one would ever exept me! Comments like "would you stop loving your girlfriend" and " does this make you gay" are unbelievable, i am female, my vagina is mine, not fake, my breasts are mine, not fake, the only similarity to a man i have is infertility.

It took me too long realise this so i dont expect the genral public to understand.

just dont be too judgemental of somone not being fully honest. Its a mean world out there!

to other anon, i used to use the cancer ovary story! but to be honest i didnt know enough at the time so it could have well been true to me!