Transgender is Not Ideology
In an executive order issued hours after his second inauguration, President Donald Trump sought to deny the reality, or even the possibility, of transgender people.
The order concerned the production of sperm and egg, known as gametes, defining a female as someone who, at conception, is destined to produce the “large reproductive cell” (egg), and a male as someone destined to produce the “small reproductive cell” (sperm). Gender, the order declared, is an “ideology,” and it instructed every federal agency to use the term “sex” instead.
Trump is partially correct about the biology of sex, but incorrect about gender and the existence of transgender people. As scientists who have studied sex and gender for many years, we can tell you that transgender people are a natural part of the human species. Transgender is not a recent ideology concocted by elite liberals to deny reality and common sense.
Across cultures and through time, societies included people corresponding to what the West now calls trans or gender diverse. Anthropologists and historians documented these people across North America, South America, Polynesia, India, Southeast Asia, ancient Rome and other parts of the world. Many cultures accepted these individuals as simply part of everyday life, often holding respected social and spiritual roles unique to their cultures.
In contrast, Western society intertwines gender diversity with medicine. Our society authorizes physicians to define what counts as “normal,” subjecting trans people to a diagnosis of illness. The American Psychiatric Association classified transgender identity as a mental illness until 2013, as it did for homosexuality until 1973.
Today, every major U.S. medical association — the American Medical Association, American Psychiatric Association, American Psychological Association, Endocrine Society, Pediatric Endocrine Society, American Academy of Pediatrics, American Academy of Child and Adolescent Psychiatry — supports transgender people and their right to appropriate care. Still, if the medical establishment can switch from pathologizing trans people to supporting them, it could switch back under political pressure.
Medical definitions of sex are unmoored from the biological definition. Today’s medical education focuses on chemistry and molecular biology, in place of zoology, botany, ecology and evolution — the subjects where natural gender diversity is encountered. Medicine uses practical but inconsistent markers to define sex, such as genitals, chromosomes and hormones. These traits statistically correlate with human sex, but do not define it. All the anatomical and behavioral traits that correlate with sex taken together describe human gender.
Zoologists, botanists, ecologists and evolutionary biologists generally define sex in this way: males make small gametes (sperm), females make large gametes (eggs) and hermaphrodites, such as most plants and many marine animals, make both.
Many animals change sex, such as coral reef fish that switch from making sperm to making eggs, or the reverse, during their lives. In turtles and other reptiles, sex is determined by the temperature at which eggs are incubated. Thus, sex may be determined well after conception according to social and environmental circumstances. And in humans, gamete production does not occur at conception. Various precursor stages appear in the fetus weeks after conception and gamete production awaits puberty.
Beyond gamete size, everything else — including secondary sex characteristics, body size, shape, color, behavior and social roles — is gender.
Gender in nature is also extraordinarily varied and fluid across plants and animals, including humans. Beyond gamete size, no general binary describes how living things look, act or relate to others. Across species, gender difference ranges from penguins with near identical male and female genders to the extreme dimorphism of lions. Human gender diversity is in the middle, showing some gender difference that varies within and across cultures.
Our society presumes a male/female binary, which is true for gamete size alone but not for gender.
So how do trans and other gender diverse people arise from this underlying gamete-size binary? Developmental biology provides the answer. From conception to birth, the human body and brain develop in a shifting hormonal environment. In mammals, genital structures develop early in fetal life, whereas the brain and many other anatomical structures, as well as behavioral traits, develop later. If hormone levels vary during these stages, the brain and the rest of the body can develop along different developmental paths, which can result in trans and gender diverse people. This is a natural and expected variation in how human development unfolds.
In matters of law and policy, “sex” actually refers to elements of gender because the criteria that have historically determined one’s “legal sex” (typically genitals, chromosomes, appearance and/or behavior) are properties of gender and not sex. As such, the courts should recognize that legal sex encompasses gender diversity.
Our overall message to policymakers and the general public is simple. For those guided by religious and ethical principles, follow the Golden Rule: “Do unto others as you would have them do unto you.” And for Christians in particular, Jesus’ teaching is clear, “Whatever you did for one of the least of these brothers and sisters of mine, you did for me.” (Matthew 25:40). These principles imply a moral obligation to understand and appreciate our shared human condition.