Seventeen out of every thousand peoplein the world are born intersex. That is to say, the medical community isn’t able to immediately assign male or female sex to 1.7 percent of newborn babies.

“If I say the word ‘hermaphrodite,’ you arrive at the imaginary,” says Janik Bastien Charlebois, an intersex activist and Sociology Professor at the University of Québec à Montréal (UQÀM). “Everyone can visualize a complete combination of typically male and typically female organs, but that’s not what intersex means. There are many possible variations.”

Janik enumerates the diverse manifestations, from birth to puberty, both visible and invisible, from external organs (for example, the combination of a larger clitoris and an outline of a scrotum, or the simultaneous presence of a penis and ovaries—the possible combinations are varied), to internal organs and chromosomal variations. (You thought only XX or XY existed? Someone with the ...