My Books

The Sexual Brain (MIT Press, 1993)

An overview of human sexuality from a biologist's perspective.

What others say:

 "In this slim and elegant volume, LeVay explores why we are sexual animals, what brain mechanisms produce sexual behavior, and how they differ in men and women. He asks 'What determines sexual orientation? Genes, events in the womb, or nurture?' A work of stunning scientific scholarship enhanced by gracious style and modesty." Los Angeles Times

"Elegantly, even wittily written, it merges evolutionary theory, endocrinology, molecular genetics and cognitive psychology into a synthesis that is brilliant and entertaining." Chicago Tribune

Available in French, German, Spanish, Italian, Dutch, Japanese, Portuguese, and Greek translations.

Return to top


City of Friends: A Portrait of the Gay and Lesbian Community in America (with Elisabeth Nonas) MIT Press, 1995.

Coauthored with Elisabeth Nonas of Ithaca College, this book surveys the history, diversity, and culture of the gay and lesbian community, and also covers health, legal, political, and religious issues.

What others say:


"A marvellous book, with a clear vision for the future, that analyzes the gay and lesbian community in all its diversity. The authors are not afraid to take controversial stands, based on a wealth of information drawn from numerous sources...Everyone can learn something important from it. Walter Williams, Professor of Anthropology, University of Southern California

Return to top


Queer Science: The Use and Abuse of Research into Homosexuality. MIT Press, 1996.

What makes people gay, straight, or bisexual? And how does research in this area influence the way gay people are viewed and treated by society?

What others say:


"Simon LeVay is a neuroanatomist and pioneer of the study of brain structures in sexual orientation. He is also a marvelous writer. In Queer Science he sums up a century of research including social learning, genes, brain structure, hormones, and much more. He then addresses the moral and legal issues posed by this research. If you have been waiting for a clear and readable exposition of sex orientation research that integrates science and politics, get this book." Richard C. Pillard, M.D., Professor of Psychiatry, Boston University School of Medicine

Available in Japanese translation.

Return to top


Albrick's Gold. Richard Kasak Books, 1997; UK: Headline Books, 1997.

This biomedical thriller is a worst-case scenario for what might happen if the technology to change a person's sexual orientation through brain cell implants should become a reality.

What others say:


"A well-plotted and imaginative bio-tech thriller." Publisher's Weekly

"A Cook-Crichton type of medical paranoia thriller...Why shouldn't we have our own Coma and Congo?" Harvard Gay and Lesbian Review

Return to top


The Earth in Turmoil: Earthquakes and Volcanoes and their Impact on Humankind (with Kerry Sieh). W.H. Freeman, 1998.

Co-authored with famed Caltech geologist Kerry Sieh, this book is a popular account of earthquakes and volcanoes from the perspective of the scientists who study them.

What others say:


"Anyone who thinks we reside on terra firma will be jolted into reality by this unique and eminently readable book, which brings earthquakes and volcanoes to life with fascinating anecdotes about how they have reshaped the world around us - and with evidence that they will continue to wreak havoc unpredictably and with devastating power." Steven M. Stanley, Professor of Paleobiology, Johns Hopkins University

"A wonderfully informative primer on two of the planet's more astounding geological forces." San Diego Union-Tribune

Return to top


Here Be Dragons: The Scientific Quest for Extraterrestrial Life (with David Koerner). Oxford University Press, 2000.

Co-authored with University of Pennsylvania astronomer David Koerner, this book is an attempt to place terrestrial life in a universal context. It describes the search for life's origins, for general principles of evolution and ecology, and for habitats for life beyond Earth. How do stars and planets come into being? Is the origin of life a fluke or a predictable process? How extreme are the conditions in which organic life can survive? Are there microbes on Mars? Are there habitable planets beyond our own solar system, and how can they be detected and studied? Is evolution a random walk or a progression toward complexity and intelligence? Is SETI a "science without a subject"? What are UFOs? Can life exist in exotic chemicals, on the surface of a neutron star, in the ultimate cold of a dying universe, or in a computer? Why does our universe seem specially designed to allow life to arise? Is our universe but one of many? This book addresses the hottest questions in the new science of astrobiology, and introduces the reader to the motley crew of scientists who are trying to answer them.

What others say:

 "A dazzling tour de force." Simon Conway Morris, Professor of Earth Sciences, Cambridge University.

Return to top


Healing the Brain: A Doctor's Controversial Quest for a Cure for Parkinson's Disease (with Curt Freed). Times Books, 2002.

Co-authored with Curt Freed, M.D., of the University of Colorado Health Sciences Center, this book is an account of the development of cell-transplantation technology for the treatment of Parkinson's disease. It focusses on a recent controversial study in which Freed's team enrolled 40 patients - men and women who were willing, at the roll of a dice, to have fetal cells implanted in their brains or to have sham surgery, and to be kept in ignorance as to which treatment they had received. This strategy led to the first scientific documentation of the effectiveness of cell therapy, but it also triggered some unexpected human dramas.

What others say:

 "A lucid and engrossing medical detective story." Publishers Weekly.

"A 'must read' for anyone . . . curious about the stem-cell controversy, or who just enjoys a real-life science thriller." Dean Hamer, author of Living With Our Genes.

Return to top


When Science Goes Wrong: Twelve Tales from the Dark Side of Discovery. Plume, 2008. (UK edition: Monday Books, 2009).

 (Represented by Andrew Lownie Literary Agency)

Mostly, we hear about science’s triumphs—the wonder drugs, the moon landings, the ever-faster computers. But for every brilliant scientific success there are a dozen failures. Mostly these involve no more than some wasted funds and a blank spot one someone’s resume. Once in a while, though, science doesn’t just fail—it goes spectacularly, even horribly wrong. And that makes for a great story.

What others say:

 “Venturing into the unknown can have unexpected consequences. LeVay offers many different explanations for what caused the calamitous mistakes he examines. Sheer bravura could account for the vulcanologists who were killed climbing into the crater of an about-to-erupt volcano. Imperfect information and a TV weatherman’s vanity led to misreporting on a hurricane that killed 18 Britons in 1987. Bad geological advice, combined with design changes made by an engineer with a God-like reputation, built a dam in the wrong place in 1920s California. That pounds-to-Newtons mistake that doomed the Mars Climate Orbiter? Faulty software that someone should have caught, but didn’t. The Houston Crime Lab’s errors in DNA testing wrongfully imprisoned a rape suspect for nearly five years, but lab reforms and the work of Innocence Network lawyers give this cautionary tale a moderately happy ending. Research on human subjects provides LeVay with some grim examples: brain surgery using fetal tissue to “cure” Parkinson’s disease; a gene-therapy experiment that killed a teenager with a genetic metabolic disorder; and a 1939 study that tried to determine whether people could be induced to stutter by telling normal children they had symptoms and should try to stop. There is little question that these cases flagrantly violated ethical considerations, primarily because the designers fervently believed their hypotheses and employed questionable methods in order to be “proved” right. In only a few instances does the author suspect coverup or deliberate intent: the horrible story of the release of anthrax spores in a Russian biological warfare factory; the alleged tampering with readouts to show production of a transuranium element; and the unresolved case of a runaway nuclear reaction that killed three scientists. LeVay’s epilogue notes that oversight and regulation have helped, but reminds us that research involves risk-taking.” Kirkus Reviews.

 "Science is deeply embedded in society, and its faults, as well as its triumphs, are society's, too. If this complex interplay interests you, this book will intrigue you to the very last sentence." Daily Mail (London)

 "Expertly narrated ... Throughout, he displays a decided verve for both story-telling and hardcore explication." Guardian (London) (read full review)

 "Amazing…entertaining…thought-provoking.” Publishers Weekly

 "Intriguing…well-told stories.” Booklist

Return to top



Human Sexuality (with Janice Baldwin). Fourth Edition. Sinauer Associates (2012)

We have discontinued this text in favor its sister text, Discovering Human Sexuality (see below)

Discovering Human Sexuality (with Janice Baldwin and John Baldwin). Fifth Edition. Oxford University Press (2021).

This is a popular undergraduate college texbook. It uses an evidence-based approach, and emphasizes diversity and the interactions between biological and social factors in sexual development and expression. It is intended to be fully accessible to students of all backgrounds.

Chapter titles:

Appendix A: Sex and Evolution

Appendix B: Sex and the Nervous System

For more information about this book, to purchase it directly from the publisher, or to request an exam copy (prospective adopters only), please visit this page on the OUP website.

Return to top




Gay, Straight, and the Reason Why: The Science of Sexual Orientation. Second Edition. Oxford University Press (2017)


Winner, 2012 Bullough Book Award of the Society for the Scientific Study of Sexuality 


What causes a child to grow up gay or straight? In this book, I summarize a wealth of scientific evidence that points to one conclusion: Sexual orientation results primarily from an interaction between genes, sex hormones, and the cells of the developing body and brain.

I helped create this field in 1991 with my own much-publicized study in Science, where I reported on a difference in brain structure between gay and straight men. Since then, an entire scientific discipline has sprung up around the quest for a biological explanation of sexual orientation. In this book, I provide a clear explanation of where the science stands today, taking the reader on a whirlwind tour of laboratories that specialize in genetics, endocrinology, neuroscience, cognitive psychology, evolutionary psychology, and family demographics. I describe, for instance, how researchers have manipulated the sex hormone levels of animals during development, causing them to mate preferentially with animals of their own gender. I also report on the prevalence of homosexual behavior among wild animals, ranging from Graylag geese to the Bonobo chimpanzee.

Although many details remain unresolved, the general conclusion is quite clear: A person's sexual orientation arises in large part from biological processes that are already underway before birth.

Chapter Titles:


1. What is Sexual Orientation

2. Why We Need Biology

3. The Outline of a Theory

4. Childhood

5. Characteristics of Gay and Straight Adults

6. The Role of Sex Hormones

7. The Role of Genes

8. The Brain

9. The Body

10. The Older-Brother Effect

11, Beyond Gay and Straight

12. Conclusions

What others say:

 "Gay, Straight, and the Reason Why [is] a comprehensive, engaging and occasionally quite funny look at the current state of the research on the topic. LeVay is one of the leading authorities in the field: Back in 1991, he discovered that INAH3, a structure in the hypothalamus of the brain that helps to regulate sexual behavior, tended to be smaller in gay men than in straight men. It was a watershed moment in our understanding of sexual orientation (the study was published at the height of the AIDS epidemic, when the disease was widely regarded in religious circles as divine punishment for the sin of being gay) and the first scientific finding to support the idea that gayness might be more than just a lifestyle." [Well, not quite the first!]

   — [Read full article]

 "Simon LeVay's theory of homosexuality in Gay, Straight, and the Reason Why nicely balances solid science and common sense ... Rational, smart, and compassionate."

   —New Scientist [Read full review]

 "Neuroscientist Simon LeVay has written an absolutely superb book, aimed at the general reader, discussing in detail what we now know. Gay, Straight, and the Reason Why should be on everyone’s reading list. ... It is clear and comprehensive, looking at the widest range of research, and very balanced. Read it, and then pass on its message to others."

  —Globe and Mail (Toronto) [Read full review]

 "LeVay provides a crisp, fair-minded, and easy-to-read summary of what recent scientific research has to say about sexual orientation and its causes."

  —Sex Roles

 “The question of how people become gay or straight is fraught with controversy, yet Simon LeVay has the remarkable ability to tackle this subject in a lively, engaging, and balanced way. He carefully reviews the literature about sexuality and sexual orientation and presents his views crisply, thoughtfully, and always with a touch of humor. There are no axes to grind or political agendas at work here: LeVay dispassionately offers a model of sexual orientation that brings together key research findings. This book is compelling, enjoyable reading and a must for anyone interested in the biological bases of sexual orientation.”

   —Bradley Cooke, Neuroscience Institute, Georgia State University

“Simon LeVay provides us with yet additional evidence of both his mastery of the research literature on sexual orientation and his skill at writing about science so that non-scientists can appreciate it. This book should be mandatory reading for everyone needing to understand the evidence for the biological basis of sexual orientation--legislators, members of the clergy, journalists, pundits, and parents.”

  —Dennis McFadden, University of Texas at Austin

Return to top


The Donation of Constantine: A Novel. Lambourn Books (2013)

Please see the book's web site.