陰陽人占全球人口顯著比例，從1.9％(Anne Fausto-Sterling, sexologist, 2000)到4％(多項研究顯示)。
What is intersex? (OII International) link
THE term intersex was adopted by science in the early 20th century and applied to human beings whose biological sex cannot be classified as clearly male or female. An intersex person may have the biological attributes of both sexes or lack some of the biological attributes considered necessary to be defined as one or the other sex.
Intersex is always congenital and can originate from genetic, chromosomal or hormonal variations. Environmental influences such as endocrine disruptors can also play a role in some intersex differences. The term is not applicable to situations where individuals deliberately alter their own anatomical characteristics.
Intersex people represent a significant percentage of the global population, from 1.9% (Anne Fausto-Sterling, sexologist, 2000) to 4% (various authors).