Are there really only two genders? Or sexes? Or whatever?

This article was written in partnership with Heming Sexual Wellness Clinic.

QUINCY — The government of the United States acknowledges the existence of two sexes, as of the issuance of President Donald J. Trump’s executive order on January 20 entitled, “Defending Women from Gender Ideology Extremism and Restoring Biological Truth to the Federal Government.”

“I signed an order making the official policy of the United States government that there are only two genders, male and female,” Trump said in an address to a joint session of Congress in early March.

Trump has typically used the word “gender” when discussing the binary existence of males and females, but his executive order states that it is sex, not gender, that is now confined solely to male and female.

However, it’s not just a matter of semantics. Sex and gender are related to one another, but they’re not the same thing.

According to the Institute of Medicine, sex is typically used as a biologic classification system and expressed as a chromosomal pattern, like XX for females or XY for males. Gender has more to do with self-representation, is typically defined by various behaviors and roles and is expressed by terms like “woman,” “man” or “non-binary.” 

The presentation of each gender can vary from one culture or time period to another. For example, a 1918 article published in The Infant’s Department stated that baby boys should be dressed in pink, “a more decided and stronger color,” and girls in the “more delicate and dainty” color of blue.

The difference in language matters, because the executive order implies the concept of gender is entirely subjective with no scientific basis and therefore isn’t real and isn’t acknowledged by the government. Trump’s comments suggest that gender is real and that there are two of them — male and female.

The conflation of the terms between the order and Trump’s comments contradict the order’s stance that “gender identity… cannot be recognized as a replacement for sex” and that “sex… does not include the concept of ‘gender identity.’” 

Some would still argue that it’s a matter of semantics. Others would say it demonstrates a lack of understanding on the topic and confusion within the administration on its stance. Regardless, the order and Trump’s comments invoke the phrase “biological reality” to frame the matter as one of common sense.

What does science actually say about our “biological reality?” 

There are way more than two genders, and there are even more than two sexes. Let’s get into it. 

The science of sex determination

The executive order defines a “female” as “a person belonging, at conception, to the sex that produces the large reproductive cell” and “male” as “a person belonging, at conception, to the sex that produces the small reproductive cell.” 

This language isn’t wrong. It’s just oversimplified and incomplete.

By this logic, men who can’t produce sperm aren’t men, and women who can’t produce eggs or are otherwise infertile aren’t women.

The widely utilized college textbook “Developmental Biology,” in production since the late 1980s and dubbed a “classic” by Oxford University Press, says “an individual’s sex is determined by the chromosome set established at fertilization.” 

The textbook goes on to say: “However, there are other schemes of sex determination.” 

The process is initiated at conception. It doesn’t conclude there.

Phase one of sex determination happens in the earliest days of a pregnancy when the chromosomal set is assigned, most commonly XX for female and XY for male. Then, little sex cells called gonads start to develop that are kind of like neutral blank canvasses for chromosomes. The presence of a Y chromosome triggers a set of hormones that transforms the gonads into testes, and without a Y chromosome, the gonads develop into ovaries.

Genes carried by each chromosome, combined with hormones created by each gonad structure, dictate phase two of sex determination, when the inner and outer genitalia are developed. XX typically results in ovary formation in phase one that produces estrogen, enabling the development of the uterus, cervix and vagina in phase two; XY typically results in testis formation in phase one that produces testosterone and anti-Müllerian duct hormones, enabling the development of the prostate gland, seminal vesicles and penis in phase two, according to the textbook.

That’s what happens in most cases, at least. Researchers estimate that anywhere from 66,000 to more than 3 million Americans are living with a disorder of sex development (DSD).

An article published in Britannica authored by biochemists and geneticists at Duke University Medical Center, Emory University School of Medicine and the University of Colorado says roughly one in every 400 males and one in every 650 females are born with a sex chromosomal abnormality. The most commonly occurring abnormalities arise in phase one and are expressed as XO, XXY, XXX and XYY and have varying reproductive and physical characteristics. 

Phase two has the potential for abnormalities, too. Androgen insensitivity syndrome (AIS), for example, is the result of a genetically irregular testosterone response in people with XY chromosomes. The presentation of this syndrome varies: those with partial AIS could develop a micropenis or have undescended testes; those with complete AIS can develop a vagina and breasts, and thus are often labeled as female at birth despite having male chromosomes. 

An enzyme deficiency in the adrenal glands causes another DSD, congenital adrenal hyperplasia (CAH). The deficiency influences hormone production, resulting in the development of male features like increased muscle mass and body hair and a deeper voice in people with XX chromosomes, the underdevelopment of such features in people with XY chromosomes and “ambiguous genitalia” in both. This abnormality makes it very possible that someone with CAH has XX chromosomes, functioning internal female reproductive organs and the external genitalia of a male.

People born with chromosomal or non-chromosomal abnormalities are often categorized as intersex — but are typically assigned male or female at birth based on their visible genitalia. 

According to the Human Rights Watch, as of 2017, U.S. doctors were still performing irreversible surgeries on intersex infants when their genitalia did not conclusively present as male or female, at times without parental knowledge or consent, to align their genitalia with one or the other. In addition to the physical and psychological effects of this practice, public health data is also impacted because many of the associated conditions go unreported.

The American Academy of Family Physicians opposes this practice and stated its concern for the lack of consent from the infants undergoing such surgeries and the irreversible effects, “including… infertility, chronic pain, inaccurate sex/gender assignment, patient dissatisfaction, sexual dysfunction, mental health conditions and surgical complications.”

If the administration’s stance is that there are only two sexes, XX for female and XY for male, it contradicts the diverse biological reality of humans according to multiple medical experts.

But all of that is just in reference to sex. What about gender?

The biological origins of gender

A reader recently asked what gender has to do with sex. Certified sex counselor Leah Heming says it has everything to do with it.

“Knowing how someone identifies their gender is as important as acknowledging their name. Some people are born with one gender and transfer to another gender,” Heming said. “When change is not allowed, situations become stagnant, and regression, panic or fear can occur.  These fall under the category of negative emotions — the most common c*ck blocker.  Can you get horny when you’re scared or panicked?”

President Trump’s executive order described the role of gender in influencing sex-based laws and policies as “invalidating the true and biological category of ‘woman’… with an identity-based, inchoate social concept.” 

Many believe gender to be a social construct, and in many ways it is, at least in the context of gender stereotypes. Nothing in our DNA says girls have to like pink, ballet and playing with dolls, nor does anything say boys have to like blue, football and playing with trucks. There definitely isn’t anything about a dress code. 

But gender isn’t limited to our learned behaviors. There is a scientific basis for it, and our understanding of how gender and sexual orientation are determined has expanded in recent years. 

A review of more than 150 pieces of scientific literature on the biological origins of sexual orientation and gender identity published in the peer-reviewed medical journal Gynecologic Oncology said that females typically identify as such, “develop feminine bone structures and body motion, and increased empathy, verbal fluency, perceptual speed and accuracy, associative memory and a sexual orientation towards men.” It said males typically identify as such, develop masculine bone structures, body motion and a lower vocal range, “math abilities and an orientation towards women.”

Chromosomal sex, reproductive systems and external genitalia are determined by a very delicate interaction of genes, hormones and proteins in the first trimester. Those factors, along with any abnormalities, continue to influence the development of the brain in the second trimester, when many male-typical and female-typical traits and features develop.

The same review says there are more than 450 quadrillion possibilities of variation between all of those hormones and proteins. These variations impact “genital anatomy, gender identity, sexual orientation and other physiologic capabilities and natural preferences.”

The president’s executive order defined gender identity as “existing on an infinite continuum.” Scientific evidence doesn’t support the idea that gender exists on an infinite continuum, but it doesn’t support the idea that gender exists between the two hardline boxes of male and female, either. 

Rather, the vast potential variations of fluctuating hormones and proteins suggest that our “genital anatomy, gender identity, sexual orientation and other physiologic capabilities and natural preferences” exist on a spectrum between masculine and feminine, according to the review.

Male and female are two opposite sides of the gender spectrum, and heterosexual and homosexual are the opposite sides of the spectrum of sexual orientation. Most people land closer to the end on one side or another, and most of the time, the side they land on is typical of their sex or gender. Some people, however, land right in the middle, lean closer to one side or another or land on the opposite side of what’s typical of their sex. 

Different variations “have been shown to correlate with many neurologic, physiologic and anatomic traits that typically express together and are congruent with sexual orientation and gender identity,” according to the review. In other words, lots of biomarkers correlate with certain genders and sexual orientations.

One biomarker is the length of index fingers in comparison to ring fingers. Girls typically have longer index fingers, while boys have shorter ones. Various studies have shown the ratio to be correlated with several preferences and play styles in children. Female-to-male transgender status and lesbian sexual orientation have been correlated with ratios that more closely resemble the male-typical ratio than the female one. In instances of twins where one is straight and the other is gay, the gay twin’s ratio more closely resembled that of the opposite sex. 

Canadian researchers found that adult lesbians often exhibit several male-typical traits, such as a lower vocal range and pain threshold, more ambidexterity and a higher sex drive. Researchers in China and the Netherlands found adult gay men to present many female-typical traits, like letter and verbal fluency, fluid body movement and speech and fingerprint patterns.

Various brain studies since the early 90s have shown a connection between brain function and sexual orientation. Gay men and lesbian women often exhibit brain activity and thinking patterns more closely resembling those of the opposite sex. Male-to-female transgender people have been observed to have similar brain structure to female brains regardless of hormone use, while female-to-male transgender people exhibit similar cognitive function to males even before starting hormones.

Prenatal exposure to various medications has also been correlated with sexual orientation and gender identity. A medication once prescribed to women in the first trimester to prevent miscarriages was eventually found by researchers in New York to increase the likelihood that her female children would be lesbian, and a group of researchers in the Netherlands linked several anti-epileptic drugs with increased rates of  male-to-female transgender status and male homosexuality.

Multiple studies have shown that gay men, on average, have more older brothers than straight men. Additionally, the more older brothers a male has, the more likely he is to exhibit gender-nonconforming traits and behaviors in childhood and adopt a feminine identity in adulthood. Though this hasn’t been fully explained, a leading theory is that an increasingly aggressive maternal immune response to male chromosomes reduces the efficacy of male-associated hormones.

This evidence supports the theory that gender and sexual orientation exist on a spectrum, and that gender and sexual orientation have real and observable biological origins, disproving that it’s a matter of choice. In other words, no one is flip-flopping their gender based on how they feel on any given day. 

Dutch neurologist Dick F. Swaab noted in a 2009 study that sexual differentiation of the genitals occurs in the first trimester and sexual differentiation of the brain occurs later. Therefore, the processes aren’t always in sync, leading to gender identities and sexual orientations that are atypical to sex. 

This study and many others not only contradict the claim that gender and sexual orientation are choices, but also that mass populations or entire generations of children could be indoctrinated into changing their gender by “gender ideology extremism.”

“There is no proof that the social environment after birth has an effect on the development of gender or sexual orientation,” the study read.

In conclusion, there are more than two sexes, there are more than two genders and there is no evidence that “gender ideology” is or could genuinely influence anyone’s sex, gender or sexual orientation — that is our “biological reality.”

Not everyone can be a neurologist, a geneticist or a developmental biologist, but anyone can approach gender with empathy.

“I believe it’s important to acknowledge someone’s gender because it’s a sign of respect and kindness,” Heming said.

This article only scratched the surface of the massive amount of scientific research on the topic. Feel free to continue your own research — because ultimately, you’re sexy when you know stuff. 

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