You’ve probably heard the term "hermaphrodite" in a biology class or maybe a Greek myth. It sounds exotic. Rare. Like something that only happens in snails or deep-sea fish. But when we talk about humans, things get a lot more complicated—and a lot more common than you might think.
First, a quick reality check. In the medical world of 2026, doctors almost never use the word "hermaphrodite" for people anymore. It's considered outdated and, honestly, a bit inaccurate. Instead, we use the term intersex.
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So, how common are hermaphrodites (or intersex people) really?
The 1.7% Mystery: Is It Really That Common?
If you spend five minutes on Google, you'll see one number pop up everywhere: 1.7%.
That number comes from Dr. Anne Fausto-Sterling, a professor at Brown University. She crunched the data from decades of medical literature and concluded that about 1.7% of all births involve some form of intersex trait. To put that in perspective, that’s roughly the same percentage of people born with red hair.
Think about that. You probably know someone with red hair. If these stats are right, you likely know someone who is intersex, too.
But here’s the kicker—not everyone agrees with that 1.7% figure.
The Great Math Debate
Some researchers, like Dr. Leonard Sax, argue the number is way lower—closer to 0.018%. Why the massive gap? It all comes down to what you count.
- The Broad View (1.7%): This includes everyone whose biological sex doesn't fit the "standard" male or female box. This covers chromosomal variations like Klinefelter syndrome (XXY) or Turner syndrome (X0), and hormonal conditions like Late-Onset Adrenal Hyperplasia.
- The Narrow View (0.018%): This only counts people where the physical appearance of the genitals is "ambiguous" at birth or where the person has both ovarian and testicular tissue (what used to be called "true hermaphroditism").
Most advocacy groups, like the Intersex Society of North America (ISNA), lean toward the higher estimate because it reflects the lived reality of people whose bodies simply don't follow the binary script.
What Does "Intersex" Actually Look Like?
It’s not just one thing. Being intersex is an umbrella that covers over 40 different variations.
Sometimes it’s obvious at birth. A baby might be born with a larger-than-average clitoris or a smaller-than-average penis. Other times, it’s totally invisible. You could go your whole life without knowing you’re intersex until you try to have kids and find out your internal anatomy doesn't match your external appearance.
Androgen Insensitivity Syndrome (AIS) is a classic example. A person with AIS is born with XY (typically male) chromosomes, but their body doesn't respond to testosterone. They grow up appearing as typical girls, often with a female gender identity, but they don't have a uterus and have internal testes instead. Often, they only find out when they don't start their period as teenagers.
The Rarest Case: Ovotesticular DSD
When people ask "how common are hermaphrodites," they are usually thinking of Ovotesticular Disorder of Sex Development.
This is the condition where an individual has both ovarian and testicular tissue. It is incredibly rare, making up only about 5% of all intersex cases. According to a case report in PubMed, these individuals might have an ovary on one side and a testis on the other, or "ovotestes"—a single gonad that contains both types of tissue.
Even in these rare cases, the body doesn't function like a "perfect" version of both sexes. Nature is messy. It doesn’t follow a 50/50 split.
Why We Don't Use the "H-Word" Anymore
Language evolves. While "hermaphrodite" is still a valid scientific term for species like earthworms that produce both eggs and sperm, it's considered stigmatizing for humans.
Back in the 19th century, doctors used it to categorize people into "true" or "pseudo" hermaphrodites. It turned people into curiosities. Today, the medical community prefers DSD (Differences/Disorders of Sex Development) or simply Intersex.
Most people in the community prefer "intersex" because it sounds less like a "disorder" that needs fixing and more like a natural variation of the human experience.
Real World Impact: It's Not Just a Stat
Knowing how common intersex traits are matters because it changes how we treat people. For decades, the standard medical "fix" for an intersex baby was immediate surgery to make the genitals look "normal."
We now know this often caused massive trauma. Many people grew up feeling like their bodies were a medical secret. By acknowledging that these variations occur in up to 1 in 100 people, we start to see it less as a "mistake" and more as a biological reality.
Actionable Insights for Moving Forward
If you’re trying to wrap your head around this or support someone who is intersex, here’s the bottom line:
- Ditch the labels: Unless someone specifically uses the term "hermaphrodite" for themselves, stick to "intersex." It’s the respectful, modern standard.
- Look at the person, not the plumbing: Biology is a spectrum. Someone’s chromosomal makeup or internal organs don't determine their worth or their gender identity.
- Educate others on the "Red Hair" rule: Remind people that being intersex is about as common as having red hair. It’s not a freak occurrence; it’s a part of human diversity.
- Support bodily autonomy: The current medical trend is moving away from "corrective" surgeries on infants. Support policies that allow intersex individuals to make their own choices about their bodies when they are old enough to consent.
Biology isn't a textbook with two neat chapters. It's a sprawling, complicated library. The more we understand the frequency of these variations, the better we can support the millions of people who live somewhere between the lines.
Next Steps for You
Check out the Intersex Campaign for Corporal Integrity or interACT to see how modern laws are changing to protect intersex kids from unnecessary medical procedures.