The Binary Delusion - by Ari Berkowitz (Hardcover)

Book Synopsis

A human physiology expert lays out the basic facts to explain why the idea of biological sex as a binary is simply wrong

Biological sex is as nuanced as gender. Many of us are biologically more typically masculine in some ways and more typically feminine in others. The constellation of traits that make up our sex identity are wide-ranging and often overlap. Height, strength, body hair, genitalia, hormonal balances--these are all part of the picture. How should we think about this kind of variation?

The Binary Delusion explores the actual diversity of our biological sex characteristics, from genitals to brains. Some people may have typically female genitals and a Y chromosome and testes, rather than ovaries. This anatomy is intermediate, not completely male and not completely female, and it occurs in nature all the time. Depending on how you choose to count, up to 6% of the population--about 20 million people in the US or 500 million worldwide--likely have sex traits that aren't exactly male or exactly female.

As a biologist, Dr. Berkowitz worries that more people aren't aware of this fundamental fact of human life. Nearly all of us manipulate our bodies in one way or another to make them appear more typically masculine or feminine. The only way to make sense of these apparent contradictions is that our society insists--regardless of our biology--that each body look a specific way from infancy until death. It's a disturbingly limited view of self-expression, and Dr. Berkowitz argues that it's worse than that: it's unscientific.

Review Quotes

"An accessible rebuttal to claims that biological sex is an immutable binary . . . Lucid, provocative, and grounded in science, this is a valuable overview of a contentious subject."
--Publishers Weekly

"Dr. Ari Berkowitz demolishes the assumption that sex is binary. Berkowitz shows huge overlap in all the physical traits people associate with sex. Sure, male/female averages differ slightly for chromosomes, genitals, muscles, breasts, butts, facial hair, body hair, voices, faces, and brain structure, but the scale of the overlap is the shocker. The writing is beautiful, containing zillions of 'huh-I-didn't-know-that' examples. Oh, this book is so timely."
--Dr. Joan Roughgarden, author of Evolution's Rainbow

"Ari Berkowitz extends the now-familiar insight of the brain and gender mosaic to the full breadth of biology. Focusing on variation and overlap across the human body, and on the processes that shape them, The Binary Delusion reveals sex as a multidimensional, overlapping, and deeply varied phenomenon. Moving from molecules to organisms, and from fungi to humans, this is a compelling and accessible guide to how biology itself resists the categories we try to impose on it."
--Daphna Joel, author of Gender Mosaic

"A succinct, accurate, and engaging explanation of why, and how, human biology is not binary. Reading this brilliant book will make conversations about, and expectations of, bodies and lives much better."
--Agustín Fuentes, author of Sex Is a Spectrum

About the Author

Ari Berkowitz, Ph.D., is a Presidential Professor of Biology and Director of the Cellular & Behavioral Neurobiology Graduate Program at the University of Oklahoma. He is author of Governing Behavior: How Nerve Cell Dictatorships and Democracies Control Everything We Do.