Most humans have 23 pairs of chromosomes. Twenty-two of these chromosomes are the same between males and females. The 23rd set are our “sex chromosomes.” (Getty Images)

Most humans have 23 pairs of chromosomes. Twenty-two of these chromosomes are the same between males and females. The 23rd set are our “sex chromosomes.” (Getty Images)

Gender aside, biological sex isn’t a dichotomy

Our biological sex characteristics and gender identities can be dynamic, and these variations enrich the human family.

  • By Wire Service
  • Wednesday, August 11, 2021 1:30am
  • Life

By Lauren Gresham / Special to The Herald

Our reproductive anatomy is wildly more dynamic than you learned in school. Most of us were taught that people are either male or female, when in fact, humans are way more beautifully diverse than a strict biological sex dichotomy.

Most humans have 23 pairs of chromosomes. Twenty-two of these chromosomes are the same between males and females. The 23rd set are our “sex chromosomes.” Males typically have an XY pair and females typically have an XX pair. However, not all people have an XY or an XX set. Some people have an extra sex chromosome (XXY, Klinefelter’s Syndrome) and other people have only one sex chromosome (X, Turner’s Syndrome). Fascinating, right?

Having the classical XY or XX chromosome configuration still does not guarantee that someone will be stereotypically male or female. In order to fully develop as male, you need a functional gene called the SRY gene, which is located on the Y chromosome. However, in some people, this gene can get deleted or modified. That means someone can chromosomally be male, but because they do not have the genetic instructions to develop as male, they will appear to be female. Likewise, someone can have an XX chromosomal pair, but the SRY gene has migrated onto one of their X chromosomes. These folks have male genetic instructions and will therefore form male anatomy, but are actually chromosomally female. Who knew?

So, if you have the stereotypical chromosome pair and the associated presence or absence of the SRY gene, then you can be considered a typical male or female, right? Wrong! We also need functional estrogen and testosterone in particular amounts. The production of our sex hormones requires many enzymatic steps, and at each step, there can be differences. And even if we make our estrogen and testosterone as anticipated, some people have variations in their receptors for estrogen and testosterone, meaning that their cells may not listen to the messages from the sex hormones in the expected way. Furthermore, growing fetuses can be exposed to hormones or hormone-like substances during certain periods of development, which can create a whole other set of ways that people can be unique.

What I have been describing are some of the ways people can be intersex. Intersex is an umbrella term that describes individuals who have biological traits that fall outside the strict definitions of male and female. Like many people, I grew up thinking that biological sex was a dichotomy. You were either “male” or “female.” Well, it turns out that our physiology is significantly more diverse than these strict two categories. And intersex traits are common, making up around 1.7% of the population (as a comparison point, identical twins make up around 0.3% of the population). Intersex traits are as common as natural redheads.

Variations in reproductive physiology may be an odd choice for a health column, but from a societal lens, equality, representation and advocacy are all important factors that influence individual and therefore, community health. Many intersex folks have experienced medical trauma and erasure of their identities in pursuit of upholding a false biological sex dichotomy. And while transgender identities and advocacy is completely distinct from intersex health, folks in either of these categories can face similar harassment and discrimination. As a physician who specializes in working with transgender and gender non-conforming folks, I hear their narratives and struggles every day. Transgender health rights are under attack in this country, with more than 100 bills currently being proposed that would restrict access to care and equal rights for transgender and gender non-conforming individuals. Many of these bills, such as sports bans for transgender kids, may also have repercussions for intersex youth.

Biodiversity creates stability within ecosystems. One plant may be resistant to a certain pest, while another may be resilient to drought conditions. Diversity makes us stronger as a species. It is truly remarkable that both our biological sex characteristics and our gender identities can be so dynamic, and these variations enrich the human family!

Want to continue the conversation, have more to add, or learned something you would like to share? Please feel free to send me a message through my website, totallylovablenaturopathic.com.

Dr. Lauren Gresham is a naturopathic physician and a community health education specialist. Learn more about her by visiting www.totallylovablenaturopathic.com.

Talk to us

> Give us your news tips.

> Send us a letter to the editor.

> More Herald contact information.

More in Life

What’s Up columnist Andrea Brown with a selection of black and white glossy promotional photos on Wednesday, June 18, 2025 in Everett, Washington. (Olivia Vanni / The Herald)
Free celeb photos! Dig into The Herald’s Hollywood time capsule

John Wayne, Travolta, Golden Girls and hundreds more B&W glossies are up for grabs at August pop-up.

Rodney Ho / Atlanta Journal-Constitution / Tribune News Service
The Barenaked Ladies play Chateau Ste. Michelle in Woodinville on Friday.
Coming events in Snohomish County

Send calendar submissions for print and online to features@heraldnet.com. To ensure your… Continue reading

Edmonds announces summer concert lineup

The Edmonds Arts Commission is hosting 20 shows from July 8 to Aug. 24, featuring a range of music styles from across the Puget Sound region.

Big Bend Photo Provided By Ford Media
2025 Ford Bronco Sport Big Bend Increases Off-Road Capability

Mountain Loop Highway Was No Match For Bronco

Cascadia College Earth and Environmental Sciences Professor Midori Sakura looks in the surrounding trees for wildlife at the North Creek Wetlands on Wednesday, June 4, 2025 in Bothell, Washington. (Olivia Vanni / The Herald)
Cascadia College ecology students teach about the importance of wetlands

To wrap up the term, students took family and friends on a guided tour of the North Creek wetlands.

Mustang Convertible Photo Provided By Ford Media Center
Ford’s 2024 Ford Mustang Convertible Revives The Past

Iconic Sports Car Re-Introduced To Wow Masses

Kim Crane talks about a handful of origami items on display inside her showroom on Monday, Feb. 17, 2025, in Snohomish, Washington. (Olivia Vanni / The Herald)
Crease is the word: Origami fans flock to online paper store

Kim’s Crane in Snohomish has been supplying paper crafters with paper, books and kits since 1995.

The 2025 Nissan Murano midsize SUV has two rows of seats and a five-passenger capacity. (Photo provided by Nissan)
2025 Nissan Murano is a whole new machine

A total redesign introduces the fourth generation of this elegant midsize SUV.

A woman flips through a book at the Good Cheer Thrift Store in Langley. (Olivia Vanni / The Herald)
Pop some tags at Good Cheer Thrift Store in Langley

$20 buys an outfit, a unicycle — or a little Macklemore magic. Sales support the food bank.

The Mukilteo Boulevard Homer on Monday, May 12, 2025 in Everett, Washington. (Olivia Vanni / The Herald)
‘Homer Hedge’: A Simpsons meme takes root in Everett — D’oh!

Homer has been lurking in the bushes on West Mukilteo Boulevard since 2023. Stop by for a selfie.

Sarah and Cole Rinehardt, owners of In The Shadow Brewing, on Wednesday, March 12, 2025 in Arlington, Washington. (Olivia Vanni / The Herald)
In The Shadow Brewing: From backyard brews to downtown cheers

Everything seems to have fallen into place at the new taproom location in downtown Arlington

Bar manager Faith Britton pours a beer for a customer at the Madison Avenue Pub in Everett. (Olivia Vanni / The Herald)
Burgers, brews and blues: Madison Avenue Pub has it all

Enjoy half-price burgers on Tuesday, prime rib specials and live music at the Everett mainstay.

Support local journalism

If you value local news, make a gift now to support the trusted journalism you get in The Daily Herald. Donations processed in this system are not tax deductible.