Sex at Dawn: The Prehistoric Origins of Modern Sexuality is a 2010 book about the evolution of human mating systems by Christopher Ryan and Cacilda Jethá.
The authors contend that mobile, self-contained groups of hunter-gatherers were the norm for humans before agriculture led to high population density.
Conversely, numerous scholars from related academic disciplines—such as anthropology, evolutionary psychology, primatology, biology, and sexology—have been highly critical of the book's methodology and conclusions, although some have commended its arguments.
The authors argue that human beings evolved in egalitarian hunter-gatherer bands in which sexual interaction was a shared resource, much like food, child care, and group defense.
The authors argue as a result that conventional wisdom regarding human nature, as well as what they call the standard narrative of evolutionary psychology, is wrong.
In other words, his assessment is skewed toward finding a fertile, healthy young mate with many childbearing years ahead and no current children to drain his resources.
Following this"she will be sensitive to indications that he is considering leaving (vigilant toward signs of infidelity involving intimacy with other women that would threaten her access to his resources and protection)—while keeping an eye out (around ovulation, especially) for a quick fling with a man genetically superior to her husband.
This change in lifestyle fundamentally altered the way people behave and has left modern humans in a situation where their instincts are at odds with the societies in which they live.
[8] Despite significant academic criticism of the research, reasoning, and conclusions of Sex at Dawn, the book received praise from many non-academic reviewers in the media.
... [Sex at Dawn] sets out to destroy almost each and every notion of the discipline, turning the field on its head and taking down a few big names in science in the process.
[3][16] Writing in the peer-reviewed journal Evolutionary Psychology, Ellsworth argues that the book misrepresents the state of current research on sexual behavior.
Noting that he could find no previous academic reviews of Sex at Dawn, Ellsworth suggests that the book's positive reception in popular media will project "a distorted portrayal of current theory and evidence on evolved human sexuality" to the general public.
He thinks reviewers read too much into the book, which merely seeks to challenge monogamy, rather than categorically reject it in favor of an alternative relationship model.
In 2012, evolutionary biologist Lynn Saxon released Sex at Dusk, a rebuttal to Dawn which itemized misrepresented citations and research errors found throughout the latter.
[citation needed] In an approving Chronicle of Higher Education review of Dusk, David Barash, co-author of The Myth of Monogamy: Fidelity and Infidelity in Animals and People wrote that Ryan and Jethá "ignore and/or misrepresent reams of anthropology and biology in their eagerness to make a brief for some sort of Rousseau-ian sexual idyll that exists—and/or existed—only in their overheated libidinous imaginations.
"Saxon ultimately denounces Ryan and Jethá's argument as "a contemporary middle-class, child-free, sex-obsessed, male fantasy projected back onto prehistory.
Gray and Justin R. Garcia dismissed Sex at Dawn in Evolution and Human Sexual Behavior (2013), writing that it was misleading and that the evidence did not support Ryan and Jetha's views.
[26] Psychologist and social theory author William von Hippel characterized the central argument of the book as "bullshit" and later as questionable among him and his peers.
"[29] Eric Michael Johnson, a graduate student in the history of science and primatology, credits Ryan and Jethá for advancing their argument using evidence not available to its previous advocates and doing so using a "relaxed writing style and numerous examples from modern popular culture.