Sex at Dawn: The Prehistoric Origins of Modern Sexuality

“Sex at Dawn challenges conventional wisdom about sex in a big way. By examining the prehistoric origins of human sexual behavior the authors are able to expose the fallacies and weaknesses of standard theories proposed by most experts. This is a provocative, entertaining, and pioneering book. I learned a lot from it and recommend it highly.” — Andrew Weil, M.D.

 “Sex at Dawn irrefutably shows that what is obvious—that human beings, both male and female, are lustful—is true, and has always been so…. The more dubious its evidentiary basis and lack of connection with current reality, the more ardently the scientific inevitability of monogamy is maintained—even as it falls away around us.” — Stanton Peele, Ph.D.

A controversial, idea-driven work of evolutionary psychology and anthropology that challenges everything you (think you) know about sex, monogamy, marriage, and family. In the words of Steve Taylor (The Fall, Waking From Sleep), Sex at Dawn is “a wonderfully provocative and well-written book which completely re-evaluates human sexual behavior and gets to the root of many of our social and psychological ills.”

What if our struggles with monogamy, jealousy, and libido aren’t a personal failure, but an evolutionary mismatch?

• The Standard Narrative: A look at how the conventional story of human monogamy was built on flawed, outdated assumptions from the Victorian era.
• Primate Politics: Why our peaceful, hypersexual bonobo cousins may be a better model for our ancestral past than the violent, hierarchical chimpanzee.
• Foraging Societies: An exploration of our hunter-gatherer ancestors, who lived in fiercely egalitarian groups that shared food, child care, and even sexual partners.
• Sperm Competition: How human anatomy—from testis size to the female orgasm—points to a prehistory of multiple mating partners for both sexes.
• Modern Relationships: A new framework for understanding why passion fades, why so many struggle with monogamy, and what it means for our relationships today.

Since Darwin's day, we've been told that sexual monogamy comes naturally to our species. Mainstream science—as well as religious and cultural institutions—has maintained that men and women evolved in families in which a man's possessions and protection were exchanged for a woman's fertility and fidelity. But this narrative is collapsing. Fewer and fewer couples are getting married, and divorce rates keep climbing as adultery and flagging libido drag down even seemingly solid marriages.

How can reality be reconciled with the accepted narrative? It can't be, according to renegade thinkers Christopher Ryan and Cacilda Jethå. While debunking almost everything we "know" about sex, they offer a bold alternative explanation in this provocative and brilliant book.

Ryan and Jethå's central contention is that human beings evolved in egalitarian groups that shared food, child care, and, often, sexual partners. Weaving together convergent, frequently overlooked evidence from anthropology, archaeology, primatology, anatomy, and psychosexuality, the authors show how far from human nature monogamy really is. Human beings everywhere and in every era have confronted the same familiar, intimate situations in surprisingly different ways. The authors expose the ancient roots of human sexuality while pointing toward a more optimistic future illuminated by our innate capacities for love, cooperation, and generosity.

With intelligence, humor, and wonder, Ryan and Jethå show how our promiscuous past haunts our struggles over monogamy, sexual orientation, and family dynamics. They explore why long-term fidelity can be so difficult for so many; why sexual passion tends to fade even as love deepens; why many middle-aged men risk everything for transient affairs with younger women; why homosexuality persists in the face of standard evolutionary logic; and what the human body reveals about the prehistoric origins of modern sexuality.

In the tradition of the best historical and scientific writing, Sex at Dawn unapologetically upends unwarranted assumptions and unfounded conclusions while offering a revolutionary understanding of why we live and love as we do.

“Christopher Ryan and Cacilda Jetha have written the essential corrective to the evolutionary psychology literature. Sex at Dawn irrefutably shows that what is obvious—that human beings, both male and female, are lustful—is true, and has always been so. The urgent sexuality that is everywhere apparent in human society and which requires layers of religious, social, and psychological suppression was likewise a constant feature on the African savannah. The more dubious its evidentiary basis and lack of connection with current reality, the more ardently the scientific inevitability of monogamy is maintained—even as it falls away around us. Thus Darwin and science have been corralled into the business of fomenting useless, irrational guilt. Drs. Ryan and Jetha make this all as transparent as glass, and do it with style.” - Stanton Peele, Ph.D.

“Turns everything you thought you knew about sex on its head. A bold and unashamed assessment of the plentiful scientific data that illuminate the true origins and nature of human sexuality. Funny, engaging, and superbly written, this book explores the science behind what many of us suspected all along: human beings are not naturally monogamous.” - Julie Holland, M.D., author of Weekends at Bellevue

“A healthy relationship with sexuality can be a strong positive influence on overall emotional and physical well-being. But understanding human sexual drives and needs and adapting them to social constraints and moral and religious precepts is tricky. Sex At Dawn challenges conventional wisdom about sex in a big way. By examining the prehistoric origins of human sexual behavior the authors are able to expose the fallacies and weaknesses of standard theories proposed by most experts. This is a provocative, entertaining, and pioneering book. I learned a lot from it and recommend it highly.” - Andrew Weil, M.D.

“Sex At Dawn challenges conventional wisdom about sex in a big way... This is a provocative, entertaining, and pioneering book. I learned a lot from it and recommend it highly.” - Andrew Weil, M.D., author of Healthy Aging

“Sex At Dawn is a provocative and engaging synthesis... that has the added benefit of being a joy to read.... A book sure to generate discussion, and one likely to produce more than a few difficult conversations with family marriage counselors.” - Eric Michael Johnson, Seed Magazine

“This paradigm-shifting book is a thoroughly original discussion of the origins and nature of human sexuality. Despite its controversial perspective, Sex at Dawn is persuasive and supported by wide-ranging interdisciplinary research. These authors have a gift for making complex material reader-friendly, filling each chapter with humor and passion as well as dozens of revolutionary insights.” - Stanley Krippner, Ph.D.

“One of the most original books I’ve read in years, Sex at Dawn manages to be both enormously erudite and wildly entertaining—even, frequently, hilarious. Ryan and Jetha slip effortlessly across millions of years, from the savannah of prehistoric Africa to the contemporary bedroom, presenting cutting-edge research with clarity and wit. A must-read for anyone interested in where our sexual impulses come from, Sex at Dawn helps explain why modern men and women behave as strangely as we often do.” - Tony Perrottet, author of Napoleon's Privates

“One of the most original books I’ve read in years, Sex at Dawn manages to be both enormously erudite and wildly entertaining—even, frequently, hilarious. . . . A must-read for anyone interested in where our sexual impulses come from.” - Tony Perrottet, author of Napoleon's Privates

“You clearly have an exciting book on your hands, whether people agree with it or not: these are issues that will need debating over and over before we will arrive at a resolution.” - Frans de Waal, author of The Age of Empathy

“So many separate moments in my life, I’ve thought in regards to something in the world, in society, ‘That ain’t right!’ What’s so unbelievably powerful about Sex At Dawn is that it makes cohesive all those separate moments…it’s helped me understand myself and the world so much more clearly.” - Ilana Glazer (Broad City)

“Sex At Dawn has helped me understand myself and the world so much more clearly.” - Ilana Glazer, co-creator of Broad City

“Sex At Dawn is the single most important book about human sexuality since Alfred Kinsey unleashed Sexual Behavior in the Human Male on the American public in 1948.” - Dan Savage

“This paradigm-shifting book is a thoroughly original discussion of the origins and nature of human sexuality... These authors have a gift for making complex material reader-friendly, filling each chapter with humor and passion as well as dozens of revolutionary insights.” - Stanley Krippner, Ph.D.

“Christopher Ryan and Cacilda Jetha have written the essential corrective to the evolutionary psychology literature...” - Stanton Peele, Ph.D.

“Funny, witty, and light ... Sex at Dawn is a scandal in the best sense, one that will have you reading the best parts aloud and reassessing your ideas about humanity’s basic urges well after the book is done.” - Newsweek

“The writing is engaging, the material covered is appropriate, and really it is the best non-technical summary I have read of the relevant issues.” - Todd K. Shackelford, Ph.D., professor of psychology, Florida Atlantic University, and editor of Evolutionary Psychology

“A wonderfully provocative and well-written book which completely re-evaluates human sexual behaviour and gets to the root of many of our social and psychological ills.” - Steve Taylor, author of The Fall and Waking From Sleep