Fembryology Part 2: Not All Is What It Seems (A Discussion of the Less Common Outcomes in Sexual Differentiation)

gender spectrum

(Please note – there are photos of genitals below – please DO NOT PROCEED if you do not want to encounter these photographs!)

Sexual Variation:  Two Sides of a Coin or A 20-sided Die?

The previous discussion on embryology began to break down how physical processes create sex differentiation as reflected in the development of the genitalia and the gonads (Testes/ovaries).

Most people are familiar with the 2-sex paradigm:

Male genitals + Male gonads = Male
Female genitals + Female gonads = Female

The development of genitals and gonads are actually separate processes that occur individually, and although they typically develop in parallel (penis/testes or vulva/ovaries), the processes are independent and their parallel development is not guaranteed.  Embryonic processes do indeed create individuals with a penis and ovaries, or those with a vulva and testes, and even genitalia that are not clearly male or female.

In fact, sexual dimorphism consists of a large range of factors that need to coordinate together to achieve distinction:

-Brain development
-Breast tissues

This is further complicated by other natural processes such as:

-evolutionary factors

This is further complicated by social processes such as:

-social acceptance or rejection of individual sexual identity (how you see yourself compared to how others see you)
-gender-based social structures (opportunities extended to each gender)
-gender roles and their enforcement
-expected gender behaviors/sexual expression (masculinity, femininity, attraction)

This is further complicated by religious teachings about “gender”:

-eternal & spiritual gender roles
-sex of the spirit
-sex-dependent exaltation (celestial marriage)
-spiritual reproduction/creation of spirit children (eternal increase/eternal parenthood)

Because of the separate pathways of embryonic development, exceptions to the two-sex-only model can and do develop.


So let’s break this down.

A note on terminology:  In feminism, and any discussion of this kind, it is important to distinguish between the words “sex” and “gender.”

-The “sex” of a person refers to male or female, as indicated by body parts.

-The word “gender” refers to the social constructions, expectations, roles, and behaviors associated with a person’s physical sex, like women wearing dresses or acting demure, or men being aggressive and expected to lead.

Heterosexual Females/Males

Here’s how we would typically understand, in a Mormon context, a “regular” man and woman (this is also how we generally see Heavenly Father and Heavenly Mother(s)):

Male genitals/gonads/chest/behaviors, attracted to females

Female genitals/gonads/breasts/behaviors, attracted to males

The impact of embryology on these two sexes has already been discussed in detail in the post Fembryology Part 1.

Homosexual/Bisexual Females/Males

What does embryology have to say about homosexuality?  There is evidence that biology may be a factor.  The pathways of embryonic development may also contribute to variations in sexual orientation and gender-related behaviors by impacting brain development. Just as hormone levels help determine the development of potential genital tissues, they also impact brain structure.

There are several areas of the brain which are possibly sexually dimorphic (which develop differently depending on the presence or absence of testosterone), and it is possible that a person with male gentalia can develop what would be classically perceived as a “feminine” brain or vice versa.  The more boys a mother has, she builds a kind of androgen immunity that affects the brain development of later pregnancies;  a boy’s chance of being gay increases with every older brother he has.  Similarly, exposing the pregnant mother to hormone treatments may statistically affect the sexual orientation of her fetus.  Another bio-behavioral factor is related to a person’s response to pheromones, which can affect sexual attraction and arousal through scent, and which may develop varying sensitivities.   However, it should be noted that homosexual individuals do not just experience their homosexuality merely as a physical/biological reality, but also as an identity, and to some this may speak to spiritual origins.


As mentioned, embryological processes are capable of creating people who have the external structures of one gender but the gonads of another (ie. Someone with ovaries and a penis or someone with a vagina and testes).  These individuals are not technically hermaphrodites (humans only RARELY develop both sets of gonads and genitalia where both are fully functional), but are termed as “intersex”.  It is controversial if they should assume the gender of their external genitalia or the gender of their gonads:  Is someone with a vagina who produces sperm a boy or a girl?  Is someone with a penis who makes eggs a girl or a boy?  Often, these individuals also have a mix of genital characteristics, making them conform to neither the male nor female genital paradigms:

female newborn Fembryology16 ambiguous-genitalia Male newborn

The above intersex babies (center photos) have either an under-developed penis or a “hypertrophic” clitoris.  There is no scrotum, as the urogenital folds remained labia, but those labia (though they are partially fused) house testes.  These individuals would be classed as “intersex”, or “pseudohermaphroditic”.  Most likely their parents would be invited to choose the baby’s sex – and the child would undergo surgery and hormone treatments to emphasize development of whichever gender the parents chose.  The act of forcing sexual dimorphism on such people remains a matter of controversy…but at the very least we observe that physically speaking, there are sexes that fall outside the male/female paradigm.  This is reality.


People who are one sex in their head, but another in their body struggle to live the gender of their body because they feel they are the other sex.

Is this a matter of the body developing along male lines while the brain develops along female lines, or vice versa?  (To be clear, this is not the case for homosexual people, who clearly identify as being the sex of their genitals.  This reflects the very major difference between gender identity and gender expression.)   Are these individuals “expected” to follow the sex of their mind/spirit or the sex of their physical body?  Is it possible that transgenderism could be an indicator of an eternal gender that, because of physical factors, ends up in a body of the “wrong” sex?

Female XY, Male XX

People may develop differently than their sex chromosomes.  An  XY may have a degenerate Y chromosome, or the embryo may be androgen-insensitive and therefore would not respond to testosterone that is present, and this can result in an embryo that is XY but develops a female body.  Is the spirit male because of a Y chromosome, or female because of the female body?

There is also such a thing as a chromosomal XX male, where the father’s X chromosome may contain a gene that is normally only on a Y chromosome. In these cases the individual will develop into a boy, but he will be sterile and will likely exhibit small testicles, and sometimes will have enlarged breast tissue and perhaps other female characteristics.  Is this individual considered a female due to the two X chromosomes, or male due to the presence of the male body?

What will a female XY or male XX look like in the afterlife?   And what implications would these situations have for the person’s access to priesthood?

XXY/XYY Genetics

It is even possible for individuals to have an XXY or XYY combination of chromosomes, leading to various internal and external outcomes.


This is a blanket term still being honed and debated, but can include people who are not “attracted” to others in a sexual sense and who do not have interest in engaging in sexual activities at all.  These individualsdo self-identify as male or female, and often even engage in non-physical romantic relationships.  It is being debated whether asexuality is a “sexual orientation” or not, and whether it is a set of behaviors or a distinct identity.

gender diamond

Hormones:  Behavior and Tissue Function

We know that sexual structures and behaviors are heavily impacted by the chemical reality of hormones.  These agents undoubtably play an enormous role in sexual development, but they can even affect and manipulate the function and manifestation of mature tissues. Since both sexes have the potential tissues of the other, but those tissues are developed or underdeveloped due to hormone levels, changing the hormone levels can change tissue function and also the person’s behavior.

For example, under certain conditions men can indeed be brought to develop lactating mammary tissue and produce milk that can flow from the nipples.


Even newborns, both male and female, can produce “milk” due to high levels of hormones during the early days of life.

Enlarged Breast Tissue Newborn     Witch's Milk

The less mature the tissue, the more impact hormones can have.  Hormone treatments cannot result, for example, in a man getting pregnant….unless he already has a functioning uterus, like this transgender man:

Pregnant Man 1   Pregnant Man 2


All this variation between physical structure, attraction, roles, behavior, and identity can be summed up nicely in this graphic:


IF the above looks complex, imagine, in the Mormon context, adding:

-sex/orientation/identity/behavior of the intelligence,

-sex/orientation/identity/behavior/fertility of the spirit, and

-sex/orientation/identity/behavior/fertility of the resurrected body.

Stepping Back:  What the heck do we do with all this?

At present, Mormonism invests enormous theological significance in the outcomes of physical developmental processes.

A good place to start is this:  considering the malleability of the human form, why does (or DOES?) God assign privileged blessings to groups of people based on their biological characteristics?  What if you could only get your temple recommend if you could bench 200 pounds, or if you had a certain BMI?  What if we had separate programs for people with blue eyes, or assigned theological significance to height or hair color (as we once did with skin color)? Even for a single individual, his/her body is changing all the time, through diet, environment, stressors, aging, illness, injury, and a host of other factors.

In Mormonism, this all leaves us with the million dollar questions:

How do the body and the spirit interact?

How does this malleable mortal coil actually impact eternal identity and salvation?

Now, you may think you know the answer to those questions.  You may not believe that anything I’ve covered in this post is significant or common enough to demand agitation about Church policy or teachings, and that’s fine.

But, at the very least:

1 – We can take responsibility to acknowledge that variation exists, and that at present, there is nothing in the gospel that speaks to it beyond “love thy neighbor”.

2 – We can take responsibility to understand where we came from, our own physical manifestations and our own identity development.  We can acknowledge how society supports that identity or rejects it.  If most of us are classic heterosexual females/males, society certainly gave us advantages, and we should not pretend that it didn’t/doesn’t.

3 – At some point, it gets difficult to reject the hard truth that mortal bodies are, to some point, malleable, and that includes anything that we would classically describe as a “gender characteristic”.  Some things may not be malleable – like the sex of the spirit.  But that doesn’t mean that those unmalleable traits MUST fall within the male/female binary.  An intersex individual’s spirit may be spiritually intersex.  A homosexual may be eternally homosexual. We have no idea about the malleability of spiritual or resurrected bodies, nor should we pretend that we do.

4 – We should not pretend that God has nothing to say, or that a Church that claims to be the Only True Church of the One True God has no responsibility to consider the valid needs of these people.  That they exist is true…if we are all God’s children,  then He is responsible for their spiritual welfare, and is obligated to speak to them.

Since he created it, I think God knows the variety better than we do.  I think God knows hearts.  I think God knows names.

I think God claims us all as his own.

Shouldn’t we do the same?