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 girl/boy or 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. In this eye-opening exploration of the science of sex, Gerald N. Callahan, PhD, challenges our notion of two opposite sexes. Human sex is more than it appears to be. Using a brief history of sex from the ancient Greeks to the geneticists of the twentieth century, he shows us how our understanding of the sexual development of human beings is constantly evolving.
By sharing the extraordinary stories of people living with intersex conditions such as hermaphroditism, Klinefelter syndrome, and androgen insensitivity syndrome, Between XX and XY reveals that the path of sexual development is as varied as humans themselves
Gerald N. Callahan, PhD is an immunologist and pathologist with more than thirty years of experience in biomedical research. He is the author of Infection: The Uninvited Universe and Faith, Madness, and Spontaneous Combustion: What Immunology Can Teach Us About Self-Perception. He is currently a professor at Colorado State University and lives in Fort Collins, Colorado.
"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
"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