From preschool onward, children learn to categorize everything – rocks, animals, plants and, of course, people. Eventually we learn to box our fellow humans into categories based on skin color, language, religion, personality type and, perhaps most basic of all, sex.
The problem with these mental shortcuts is that the world is full of exceptions that blur the boundaries. Nature can be creative in producing intermediate cases.
That’s why there’s not just an ethical argument but a scientific case to be made against the new law in North Carolina that requires everyone – including transgender people – to use the public restroom that corresponds to their sex at birth.
Novelist Ian McEwan recently summed up the impulse to see two categories: “Call me old-fashioned,” he told an audience, “but I tend to think of people with penises as men.” Someone should send him a copy of the enlightening “Middlesex” by fellow novelist Jeffrey Eugenides.
The story is based on a real condition called 5-alpha-reductase deficiency, which can lead to a state between having a penis and not having one. How is such a thing possible? Developmental biologists have a good explanation.
All human embryos are equipped with the starter kits for both male and female sexual anatomy. Every part on the male body has an analogous part on the female body. The starter kit includes something called a genital tubercle. Whether it eventually becomes a penis is determined by a multistep process.
In high school biology, this is presented as a matter of chromosomes. Two X chromosomes? Female. One X and one Y? Male. But these are just the starting switches for a complicated process in which genes on various chromosomes become activated and trigger precisely timed releases of hormones. There are lots of possible outcomes, depending on which switches are flipped and when. Not everyone comes into the world with a clear-cut sex. Not everyone who appears at birth to be either male or female is. And this is just the simple stuff – the biology –setting aside other dimensions like gender, gender identity or sexual orientation.
In the condition described in “Middlesex,” for example, people with the most common “male” XY chromosome combination are born with ambiguous or female-looking genitalia because they lack an enzyme called 5-alpha-reductase, which turns out to be critical for shaping male organs in utero.
In the novel, the protagonist, Callie, is assumed to be a girl, but when she hits puberty, she shoots up to 6 feet tall, her voice cracks, her breasts stay flat, her somewhat ambiguous genitalia edge toward the male end of the spectrum, and she grows a mustache. The family members are not altogether thrilled to see their teenage daughter become a man.
Five-alpha-reductase deficiency is one of many roads to middlesex, or, in proper medical terminology, intersex conditions. In a 1993 essay called “The Five Sexes,” biologist and women’s studies professor Anne Fausto-Sterling cited a number of examples from medical literature, including the 1937 story of Emma – a married woman who was endowed with a set of genitalia that “made it possible for him/her to have ‘normal’ heterosexual sex with both men and women.”
Beyond male and female, Fausto-Sterling suggested three other sexes: female pseudo hermaphrodites, who have ovarian tissue and some male physiology; male pseudo hermaphrodites, who have testes and some aspects of female genitalia; and true hermaphrodites, who have both ovaries and testes. Sometimes this happens when two embryos that might have become fraternal twins fuse to become one baby. If the fused embryos were of opposite sexes, the baby can have a patchwork of male and female cells.
Why is the biology of sex more complicated than male and female? One reason is that evolution builds new sex-determining systems on top of older ones in a Rube Goldberg fashion. In many fish and reptiles, sex is determined not by chromosomes but by the temperature the egg experiences. Environmental changes can prompt some fish to change sex entirely. There are also myriad systems involving sex chromosomes. The platypus has a superabundance of them. Females are XXXXXXXXXX and males are XXXXXYYYYY. Even in the much simpler human system, people end up with XXY, or XYY, X, or other permutations.
Biology does have some unbreakable rules, and one is that diversity is necessary for evolution. Intersex and transgender are different categories, encompassing many situations that don’t map onto a decision of “men’s restroom versus women’s restroom.” And so the new laws in North Carolina and elsewhere will affect transgender people and many others.
There’s also a deeper level to the debate swirling around restroom access, said historian Alice Dreger, author of “Galileo’s Middle Finger: Heretics, Activists, and One Scholar’s Search for Justice.” The need to fit into the world of gendered bathrooms and locker rooms is the justification doctors sometimes give for performing surgery on infants born with ambiguous genitalia. Doctors often guess a gender, she said, but it’s not always how the person ultimately identifies. These surgeries are dangerous and not easily reversible.
And what if, as one writer asked, you’re “an American with traditional views on gender, your kids are in a public school, and the girls’ locker room has just been declared a gender-fluid zone”? Indeed. What if it has been? That declaration was a long time coming, given that all locker rooms, and all of nature, have always been a gender-fluid zone.
So perhaps science can add something to the debate by showing where these restroom laws are not only hurtful but also unrealistic. Not everyone fits neatly into the categories of male and female, but everyone needs to go to the bathroom.
Faye Flam writes about science, mathematics and medicine. She has been a staff writer for Science magazine and a columnist for the Philadelphia Inquirer.