"Sex can be much more complicated than it at first seems. According to the simple scenario, the presence or absence of a Y chromosome is what counts: with it, you are male, and without it, you are female. But doctors have long known that some people straddle the boundary—their sex chromosomes say one thing, but their gonads (ovaries or testes) or sexual anatomy say another. Parents of children with these kinds of conditions—known as intersex conditions, or differences or disorders of sex development (DSDs)—often face difficult decisions about whether to bring up their child as a boy or a girl. Some researchers now say that as many as 1 person in 100 has some form of DSD."
Biologists now think there is a larger spectrum than just binary female and male
www.scientificamerican.com
Which reminds me, you never responded to my question on someone who has XXY chromosomes. What are they, male or female?