Chromosomes and Gender

In August 2017, an organization called The Council for Biblical Manhood and Womanhood published a document called the “Nashville Statement”, which makes declarations on a number of issues related to gender and sexuality.

One of its Articles introduces the term “biological sex”:

We affirm that those born with a physical disorder of sex development are created in the image of God and have dignity and worth equal to all other image-bearers. They are acknowledged by our Lord Jesus in his words about “eunuchs who were born that way from their mother’s womb.” With all others they are welcome as faithful followers of Jesus Christ and should embrace their biological sex insofar as it may be known.

The phrase “biological sex” may conjure memories of middle school health or biology classes. If pressed to provide a definition of it, you might appeal to chromosomes, eggs and sperm, or perhaps reproductive organs.

In fact, a wide variety of sex characteristics are all rooted in biology:

• Chromosomes
• Secondary sex characteristics
• Hormone levels
• Gonads (internal reproductive organs)
• Genital configuration
• Gender identity (at least insofar as it has been linked to brain structures)

For most individuals, these characteristics are aligned with each other, allowing us to make reasonable statements about their “biological sex”.

But what about when they don’t match up? Which of them should be considered a person’s “real” sex when we encounter inconsistencies between—or within—characteristics?

It is surprising that Article VI gives no guidance on this issue, given that people with ambiguous or inconsistent sex characteristics are precisely those who are being exhorted to “embrace their biological sex”.

This lack of clarity is no minor detail. All of the declarations of the Nashville Statement are based on Complementarianism, which calls for people to adhere to strictly assigned gender roles.

The president of the council that published it, Denny Burk, recognizes that any ambiguity in this area is a major problem:

If biological sex is unclear, then so also is any notion of normative gender roles. That is why intersex is an ethical conundrum for complementarians. Our whole paradigm is based on the givenness of clearly indicated biological sex.

A couple of pages later, he clarifies exactly what is at stake:

Complementarians assume the dimorphic paradigm in establishing gender roles. If that assumption is taken away, then the whole system collapses. If biological sex is rendered ambiguous or something to be graphed on a spectrum, then the assignment of God-ordained gender roles is rendered ambiguous as well.

In other words, the validity of complementarianism depends on our ability to agree on an objective set of criteria for categorizing every human as either “male” or “female”.²

Over the course of the next several posts, I intend to explore a number of schemata that have been used for sex classification, with special attention to assessing whether any of them are sufficiently strong to hold the weight of complementarianism.

The focus of this post is chromosomes. This characteristic is often favored because of its relative lack of ambiguity and its presence all the way back to the conception of each human.

Somewhere along the way, you probably learned that boys have XY chromosomes and girls have XX chromosomes. While this holds for most people, it is insufficient to describe everyone.

To start with, there are far more than two alternatives for chromosomal configuration.

For example, an individual with Klinefelter Syndrome has XXY chromosomes. People with this syndrome are generally assigned male at birth but develop somewhat atypical secondary sex characteristics at puberty—although the signs are sufficiently subtle that they may go undetected for a lifetime³. Individuals with XXXY or XXXXY chromosomes have also been observed; these configurations often cause development that is similar to those with Klinefelter Syndrome, albeit with more severe health problems.

Similarly, XYY Syndrome is precisely what you’d expect. There are few observable symptoms, and it usually goes undetected.

There are also additional chromosomal variations that do not include a Y chromosome, like Turner Syndrome (just a single X chromosome) and Triple X Syndrome.

And then there’s mosaicism, in which different cells have different chromosomes. Mosaicism comes in a number of different forms and is associated with a wide variety of physical traits.

With so many natural variations, using chromosomes to sort everyone unambiguously into “boy” and “girl” categories no longer seems quite so simple.

In a survey of many of the early signatories of the Nashville Statement⁴, a large group clarified their position on the question of sex assignment by referring to What is the Meaning of Sex?, which I cited above.

In that book, Burk expressed his position strictly in terms of Y chromosomes:

Even when abnormalities occur in chromosomes, they still comprise some combination of Xs and Ys. The reproductive possibilities for intersex persons seems to align with the chromosomes. Male reproductive capacity comes only from those who have Y chromosomes. Female reproductive capacity comes only from those who have no Y chromosome. Is this not reflective of the dimorphic paradigm of Scripture?

Similarly, he clarifies his position on the next page:

If there is a Y chromosome present, that would strongly militate against raising the [intersex] child as a female, regardless of the appearance of the genitals and other secondary sex characteristics.

What is the Meaning of Sex?, Denny Burk, page 181

This is certainly unambiguous. For Burk—and many other signatories of the Nashville Statement—“biological sex” is synonymous with answering the question, “Is a Y chromosome present?” Given the simplicity with which this position can be articulated, it is curious that it was not included in Article VI.

However, while this makes for an elegant theory, it is not terribly practical: most people never take the karyotype test that definitively screens for a Y chromosome. Is a person who doesn’t know their chromosomal configuration “living in sin” if they make an incorrect guess?

This may seem like an extreme interpretation, but it does not seem to be an unfair characterization of Burk’s position. Elsewhere, when discussing a condition⁵ in which individuals with feminine physiology discover—typically no earlier than puberty—that they have XY chromosomes, he insists, “But that doesn’t preclude us from helping them to see that they are essentially male in spite of ambiguities in external features.”⁶

Practical implications aside, the Y-chromosome-means-boy model begins to show limitations even within the realm of genetics.

The typical role of the Y chromosome in sexual development has been understood since the 1960s. However, in 1985, the presence or absence of the SRY gene was identified as having an even more direct effect on whether an individual develops in a typically male or typically female pattern.

This gene is usually present on the Y chromosome, but it occasionally migrates. This can result in XX individuals with male features or XY individuals with female features. While abnormalities such as infertility are often associated with these genetic configurations, the symptoms of a “misplaced” SRY gene are sufficiently subtle that they can go undetected for a lifetime.

According to the Y-chromosome-means-boy model, the majority of these people are living in defiance of their appropriate gender roles. Moreover, any who lived prior to 1985 would have had no clue as to their transgression. This stretches credibility.

On the other hand, it’s possible that when Burk said “Y chromosome”, he was really using this term as a proxy for the SRY gene. But if this is the case, then what of the people who grew up between the development of our understanding of the Y chromosome and the discovery of the SRY gene?

Consider this scenario:

A parent from the Y-chromosome-means-boy camp has a child with XX chromosomes and an active SRY gene. The parent has the child tested, discovers that there is no Y-chromosome, and decides to raise this child as a girl—despite the child having a typically male physiology.

At some point, the parent gains an awareness of the SRY gene’s role in human development and decides that this is a more effective way to assess gender. The child is tested, the gene is discovered, and the parent switches to raising the child as a boy.

Several years down the road, a new discovery is made in genetics that seems like an even better way to assess gender. The child is tested, and reassigned female.

At what point does this become absurd? Can you imagine the mental whiplash that someone would experience in such an upbringing? This scenario rather reminds me of the Dr Seuss story about the Sneetches, in which the eponymous creatures go back and forth—having stars added or removed from their chests—in order to win the approval of others.

But instead of stars, we’re talking about something as complex and multi-faceted as gender. Actually trying to raise a child in this way would be tantamount to child abuse.

While the Y-chromosome-means-boy model does have the benefit of consistency, it achieves this through imposing arbitrary rules that are likely to be subject to future revision.

These revisions are unlikely to have much effect on people whose genes fit expected patterns—or who never bother to get tested—but it could inflict incalculable harm on those who already tend to be marginalized by the model.

In addition to failing within the modern world, it is also out of step—sometimes wildly so—with how the Biblical authors would have assigned gender, given their lack of access to modern medical knowledge and testing. For an organization attempting to promote a “Biblical” view of gender, this seems like a curious choice.

While models of sex based on chromosomes are useful in many situations, their limitations make it dangerous to use them as the basis for insisting that others conform to expected gender roles.

This also highlights the wider danger of entangling scientific knowledge with moral teaching: often, scientific understanding outpaces ethicists’ ability to keep up.

Looking for the rest of the series?

1. Chromosomes and Gender
2. Reproduction and Gender
3. External Sex Characteristics and Gender
4. …Coming eventually