Stephen Snyder M.D.


Sex at Dawn Author Christopher Ryan on Prehistoric Polyamory

Group Sex in Our Collective Past? Why We Should Care.

Posted Aug 18, 2010

We moderns tend to think of sexuality as the province of more-or-less monogamous couples, bound together by bonds of love, romantic possessiveness, and jealousy. But according to Sex at Dawn authors Christopher Ryan and Cacilda Jetha, before 10,000 years ago the basic human sexual unit may not have been the couple at all, but rather the small nomadic hunter-gatherer group. Because nature provided for all their needs in abundance, these early humans would have had no modern concept of ownership or property. Everything would have been  shared with the group, including sex. Sexual promiscuity would have been the rule rather than the exception.

Accounts of actual hunter-gatherer societies, from Captain Cook's Polynesians to recent inhabitants of the Amazon rainforest, confirm the above narrative in all respects. The evidence from comparative anatomy is even more compelling. As Ryan summed it up in a recent PT blog article, "women's breasts, orgasms and reproductive anatomy echo the same story told by men's testicles, penises, and seminal chemistry. It's an X-rated tale of the orgiastic origins of our species."

After the dawn of agriculture 10,000 years ago, according to this theory, when humans settled down to work the land, the organizing principle of human existence changed from abundance to scarcity. Individual ownership of land and other precious resources became the norm. Sexual life was transformed as well. In the new ownership societies, one person could now claim another as his or her exclusive sexual property. Cultural institutions arose to enforce sexual exclusivity. Chief among these was the new cultural ideal of monogamy.

In our modern world's fascination with the infidelities of its leaders and celebrities, the authors of Sex at Dawn see a vague recollection of a bygone era when sexual liberty was everyone's birthright.

Lead author Christopher Ryan
is an American psychologist living in Barcelona (and a fellow PsychologyToday sexuality blogger). I was able to persuade him to make time for the following interview --

Author Christopher Ryan

Christopher, many authors have noted that the human body seems designed to generate near-constant sexual interest. Your book offers an explanation why -- because it motivated early hunter-gatherers to mate promiscuously, which was good for the group.

We've known that grooming behavior was crucial to maintaining social networks among group-living primates. But this same logic hadn't really been applied to sexual contact before.

Your idea that the basic sexual unit in hunter-gatherer societies may not have been the couple, but the group -- how did this idea come to you?

When I was working on my PhD dissertation, back in the late 1990s, I read Lewis Henry Morgan's Ancient Society (1877). Morgan is largely forgotten today, even among anthropologists. He spent long periods living among Indian groups in upstate New York, and wrote about the "primal horde" as an early stage of social organization. I suppose it was Morgan who really got me started down this path.

Reading your book, I thought, "Of course early human sexuality was a group affair. They didn't have bedroom doors."

Right. There was very little privacy for most of our existence as a species. Even today, many pre-agricultural people live in communal dwellings where sex is at least a semi-public event. 

Click HERE to read the rest of this interview on

© Stephen Snyder, MD 2010
New York City 

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