INTERSEX refers to individuals born with sex characteristics that are not typically male or female. It is an adjective, like the term “gay,” meaning someone “is intersex,” not, “is an intersex.” For the noun form, one would say someone is, “an intersex person,” “an intersex individual,” or, in plural, we are, “intersex people.”

Intersex people can look typically male, typically female, or androgynous, as there are an estimated 30 types of intersex traits comprised of variations in chromosomal patterns, reproductive organs, genitalia and/or hormones. In addition, intersex people live and identify our gender in a variety of ways, just like non-intersex (endosex) people. We can be women, men, intersex women, intersex men, herms, intersex persons, non-binary persons, etceteras.

We highly recommend the United Nation’s INTERSEX FACT SHEET, which we are very proud to have consulted on, if you are looking for a short resource to educate others about intersex people and our human rights issues.


The most thorough existing research finds intersex people to constitute an estimated 1.7% of the population*, which makes being intersex as common as having red hair (1%-2%).

Some groups use an old prevalence statistic that says we make up 1 in 2000, or .05%, percent of the population, but that statistic refers to one specific intersex trait, genital variance (aka ambiguous genitalia), which is but one of many variations which, combined (as they are in medical diagnostics and coding), constitute the 1.7% estimate by biology and gender studies professor Dr. Anne Fausto-Sterling, of Brown University*.

A similar, slightly higher, statistic was also reported in, “How Sexually Dimorphic Are We?”, by Blackless, et al, in The American Journal of Human Biology. “The belief that Homo sapiens is absolutely dimorphic with the respect to sex chromosome composition, gonadal structure, hormone levels, and the structure of the internal genital duct systems and external genitalia, derives from the platonic ideal that for each sex there is a single, universally correct developmental pathway and outcome. We surveyed the medical literature from 1955 to the present for studies of the frequency of deviation from the ideal male or female. We conclude that this frequency may be as high as 2% of live births. The frequency of individuals receiving “corrective” genital surgery, however, probably runs between 1 and 2 per 1,000 live births (0.1–0.2%).” Am. J. Hum. Biol. 12:151–166, 2000. © 2000 Wiley-Liss, Inc. http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1520-6300(200003/04)12:2%3C151::AID-AJHB1%3E3.0.CO;2-F/abstract These two findings are the most thorough scientific research which exists on the statistical prevalence of congenital intersex traits in humans.

The erroneous belief that we are an extremely tiny percentage of the population is often used to dismiss our need for legal rights and protections. We therefore encourage everyone — particularly allies and/or members of the press educating others about intersex people — to please use the information and prevalence statistic provided here to accurately do so. Thank you!

 * Fausto-Sterling, Anne (2000). Sexing the Body: Gender Politics and the Construction of Sexuality. New York: Basic Books. ISBN 0-465-07713-7.

The Intersex Society of North America (ISNA, 1993-2008), popularized the “1 in 2000” (.05%) statistic, but clarified on its website:
“Here’s what we do know: If you ask experts at medical centers how often a child is born so noticeably atypical in terms of genitalia that a specialist in sex differentiation is called in, the number comes out to about 1 in 1500 to 1 in 2000 births. But a lot more people than that are born with subtler forms of sex anatomy variations, some of which won’t show up until later in life. Below we provide a summary of statistics drawn from an article by Brown University researcher Anne Fausto-Sterling….”

Additional Info

Intersex traits comprise chromosomes, genitals, hormones and/or gonads that do not fit typical definitions of male or female, and can result in additional variations in secondary sexual characteristics such as muscle mass, hair distribution, breast development, hip to waist ratio and stature.

Intersex is historically defined by biology, rather than gender identity, as intersex people experience the same range of gender identities as non-intersex people do. We note however, that some intersex people have discussed that “intersex” describes their gender identity as well as the sex characteristics they were born with. We also note that the terms “male” and “female”– thought to be used exclusively to refer to biology– are also used to refer to gender/gender expression/gender identity in the case of some intersex people. For example, those with CAIS are not assigned male, whoci would be accurate according to strictly biological definitions of sex, but female to reflect their predominant gender/gender expression/gender identity as women.