There is a population of people whose lives are shaped by a simple biological fact that the medical and social systems around them have never quite figured out how to hold honestly. Intersex people — those born with physical sex characteristics that don't fit typical definitions of male or female — exist at a frequency that most people would find surprising, and they navigate an experience that most people never think about at all.

What Intersex Actually Means

Intersex is an umbrella term for a range of naturally occurring variations in chromosomes, hormones, gonads, or genitalia that fall outside what medicine has historically classified as standard male or female. These variations include conditions like congenital adrenal hyperplasia, Klinefelter syndrome, androgen insensitivity syndrome, and dozens of others. Some intersex variations are visible at birth. Others don't become apparent until puberty or adulthood, or are only discovered incidentally during medical care for something else entirely. Estimates of intersex prevalence vary depending on which conditions are included, but Anne Fausto-Sterling at Brown University, whose work on biological sex has influenced how researchers understand this area, has estimated that roughly 1.7% of the population is born with some intersex characteristic. That's roughly comparable to the rate of red-haired people, which suggests intersex people are uncommon enough that most people don't know they've met one — but common enough that treating intersex as a medical aberration rather than a natural human variation deserves serious scrutiny.

The History of Medical Intervention

Here's where things get complicated in ways that matter. For decades, the standard medical response to intersex infants born with ambiguous genitalia was surgery — performed on infants who could not consent, aimed at producing bodies that fit legible male or female categories. The surgeries were often irreversible, sometimes resulted in significant loss of sensation, and were accompanied by a culture of secrecy in which families were advised not to tell children what had been done to them or why. Research published by the journal PLOS ONE in 2020, based on a large survey of intersex adults, found that individuals who had been subjected to non-consensual childhood sex-normalizing surgeries reported higher rates of psychological distress, trauma symptoms, and regret than those who had not. Several human rights bodies, including United Nations treaty bodies, have characterized non-consensual intersex surgeries as a form of harm requiring protection. Medical practice has been shifting, though unevenly. More pediatric endocrinologists and urologists are now advocating for deferring irreversible surgeries until individuals can participate in the decision. But the shift is incomplete, and many intersex people living today carry the effects of the older approach.

Identity Versus Diagnosis

There's an important distinction between intersex as a biological description and intersex as an identity. Many intersex people don't use "intersex" as a primary identity term — they may identify with a specific condition, with a gender identity, or simply as themselves. Others have embraced intersex as a political and community identity, particularly in the context of advocacy against non-consensual medical interventions. This is worth noting because conversations about intersex sometimes collapse it into conversations about transgender identity, which, while related in some ways, is a different thing. Intersex refers to biological sex characteristics. Transgender refers to gender identity. An intersex person may or may not be transgender. A transgender person may or may not be intersex. Conflating the two tends to muddy both.

The Tangent About Sex as a Spectrum

The existence of intersex people is often cited in debates about biological sex, and I want to be careful here because those debates generate more heat than understanding. What intersex biology demonstrates is not that biological sex is meaningless or purely social — it demonstrates that biological sex, even at the level of chromosomes and anatomy, is more variable than the two-category model captures. Sex characteristics exist in distributions, not just in two discrete boxes. Intersex people aren't exceptions that disprove a rule; they're part of the natural range of human biological variation. The society that is still struggling to make room for intersex people is one that treats this variation as a medical emergency to be corrected rather than a human difference to be understood. Getting more honest about that costs very little — and for intersex people navigating a world built on assumptions that exclude them, it means considerably more than that.