Overview

Just like noses, sexes come in all shapes and sizes

“On October 10, 1970, the day she was born, she was named Dorothy Maree Alaniz--a baby girl. Curiously, though, no one filled out a birth certificate that day. When the certificate was finally filed on November 5, the name on it was Rudolph Andrew Alaniz. Within less than one month after her birth, this girl became a boy.” Every year in the United States, more than two thousand children are born with an intersex condition or disorder of sex development. What makes someone a boy or a girl? Is it external genitalia, chromosomes, DNA, environment, or some combination of these factors? Not even doctors or scientists are entirely clear. What is clear is that sex is not an either-or proposition: not girl/boy, XX/XY, switching between two poles like an on-off switch on a radio. Rather, sex is like the bass and treble knobs on that radio. Between XX and XY provides a fascinating look at the science of sex and what makes people male or female. There are people born XXY, XXXY, or XXXXY, or with any number of variations in X or Y chromosomes, but those who do not fit into society’s preconceived notions about sex often face a difficult path in life. Dr. Callahan explores why humans are so attached to the idea of two sexes, and examines our obsession with sex and sexual intercourse through the ages.

Reviews

"Callahan does a good job of exploring intersex individuals, who are neither male nor female, and argues that they need to be accepted for what they are and not viewed as defective."  —Publishers Weekly

"Immunologist Callahan takes a fascinating look at the biology and human experience of intersexuality, a state in between male and female."  —Discover Magazine

"Callahan's writing style is both accessible and engaging; it reads more like creative non-fiction, a la Malcolm Gladwell."  —Ms. Magazine

"This is a fascinating, easily understandable journey into why we are born male or female and examines our age-old obsession with sex."  —Fort Collins Coloradoan

"There are lots of interesting nuggets here—for example, Callahan's description of biological sex as a spectrum, not a binary system."  —Double X

"The book is really beautifully written, highly accessible, and visionary in its own right."  —Feministing

"This book takes readers through an alphabet of gender and gender variations. Callahan shows readers that rather than either/or scenarios, there have always been variations; his book shatters our society's take on pink and blue."  —Advocate.com