Kim Kardashian and Kanye West at the 2015 Metropolitan Museum of Art's Costume Institute Gala. (TIMOTHY A. CLARY/AFP/Getty Images)
Caitlin Flanagan is a contributing editor at the Atlantic and the author of “Girl Land.”

Caitlin Flanagan is a contributing editor at the Atlantic and the author of “Girl Land.”

Almost 50 years ago, a British zoologist, surrealist painter, television producer and former curator of primates at the London Zoo named Desmond Morris published what remains one of the greatest works of pop science ever written: “The Naked Ape.” The idea was that humans are, at base, merely one species among many and that their methods of “fighting, sleeping, mating and rearing their young” ought to be studied in the same unsentimental way that these behaviors are studied in other species.

It was an intentionally racy book — humans, it revealed, have the biggest penises of all the apes; are the “sexiest primates alive”; and, through the twin forces of evolution and sexual selection, have developed female breasts so unnecessarily large that they are clearly a form of sexual signaling. With its sexy subject, its academic jargon and its scholarly writer (among his other accomplishments, Morris had a Ph.D. in philosophy from Cambridge), it became an international bestseller, and it made the author a celebrity.

Now, half a century later, David Bainbridge, a Cambridge-educated expert in veterinary sciences, attempts to do something similar with “Curvology,” a book that takes “an evolutionary and zoological approach to the origins and power of female bodies.” The author is interested in the “curvy” parts of women — breasts, thighs and buttocks — and in the ways they have evolved in response not only to the demands of reproduction but also to male sexual desire. This would seem well-explored territory, but Bainbridge has a second goal: to explain how modern women attempt to reconcile their evolutionary inheritance of curves with the current vogue of thinness. Moreover, he instructs us in the ways in which modern heterosexual men — no matter how “evolved” — are incapable of rising above the rules of sexual attraction that were cemented long, long ago.

“Evolution is not feminist,” he tells us soberly. Neither is he, apparently, which gives the book a refreshing frisson. Most pseudo-scientific books aimed at a female readership (as this one clearly is) are devoted to proving the superiority of women or at least their full equality to men. The “I’m just telling it like it is” tone of “Curvology” is appealing: What dark truths have we been unwilling to face? Read a chapter or two, however, and you discover that “Curvology” merely — and mildly — repeats the assertions of the manosphere: Evolution has caused men to like big breasts, big buttocks and small waists. We know, we know! Didn’t the Commodores teach us long ago that 36-24-36 is a winning hand?

It turns out that Bainbridge, who reveals a Henry Higgins-like frustration with women and their inability to accept science and think logically, is a mansplainer of prodigious talent. No concept is too simple for him to break down into graspable chunks for the dizzy broads who pick up the book. “Of all the animals in existence,” he patiently explains, “only humans seem to feel the compulsion to wear clothes.” We know this is deep, scientific stuff because of the word “seem.” “Over half of the human brains in existence,” he reports, “just happen to have found themselves lodged inside a female body.” By God, he’s right.

Each chapter includes remarks from five anonymous women whom Bainbridge interviewed about their bodies. They tell him things: “I tend to look in the mirror for confirmation that I look as bad as I think I look” and “I feel guilty about most things I eat.” Then — sparing no effort in the name of science — he makes a visit to the newsstand, where he encounters women’s magazines with headlines about cellulite and dieting. Bottom line: Modern woman is a wreck, either knocking herself out with sleeping pills to keep from snacking, dressing herself in pink and red clothing during ovulation in an unwitting attempt to get impregnated, or moping about her “bingo wings, love handles, and muffin tops.”

Whatever scientific dispassion Bainbridge brings to his subject tends to fall away whenever he considers breasts, which is often. “Most women’s breasts are not large enough to contact each other and form a cleavage without artificial support,” he tells us, and that’s why there are fabulous bras that “can push the breasts together as well as upwards, and thus give almost any woman a cleavage.” Big breasts are, of course, excellent, but caveat emptor — they sag over time. “As women get older,” he writes, “men potentially face a sexual dilemma between choosing partners with large breasts or with youthful-looking breasts.” That there is presumably some sort of host organism attached to these breasts goes unconsidered. It’s not all a downer, though, for the gal whose youth was a horror show: “Women with smaller breasts are likely to be pleasantly surprised in middle age when their breast shape remains more youthful than their more buxom friends.”

“Visual appearance is at the center of human female life,” he reports definitively and inaccurately, a belief that leads him to give outsize importance to the “fat talk” of his interviewees and to the headlines of women’s magazines. If he’d asked these five women about their careers, their children, their aspirations, he might have gotten the impression that there is more to modern women’s lives than moping about their diets. Morris published his book in 1967, a moment when the sophisticated suburbanites who made it a hit really could see parallels between their lives and those of early humans. Most married women in that group did stay home to raise children and tend the hearth; most married men did work outside the home and provide for wife and children. But the world is a different place now, and women have different means of providing for themselves than landing a naked ape. Nor do they seek out the opinion of a veterinarian — not even one from Cambridge — when they are trying to understand their motivations and experiences.

There is exactly one truly happy female in “Curvology,” an unnamed girl who appears in two italicized passages that Bainbridge has dreamed up as a sort of homage to “Clan of the Cave Bear.” We meet her in “the rust-red light of another dawn.” Her family has traded her to a tribe of strangers, which might seem like a raw deal, but her full thighs and round bottom have led to the assurance that “she would be cherished by her new tribe and her man.” Indeed, this man has already planted his seed in her. All this — the human trafficking, the rape, the pregnancy — leads to the deepest delight: “She cupped her breasts in her hands. They seemed to be getting slowly larger ever since the wiggling thing in her belly had appeared. She could not explain why, but this made her laugh out loud.”

She’s barefoot and pregnant, and if she’s not in the kitchen it’s only because her man hasn’t gotten around to inventing one yet. She’s got all the right junk in all the right places, and a great attitude. Life makes sense to her. And so, unlike the sad sacks Bainbridge talked to about their muffin tops, she can laugh.

Curvology
The Origins and Power of Female Body Shape

By David Bainbridge

Overlook.
227 pp. $26.95