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It was a figure I kept hearing again and again: 50 percent of South African women can now expect to be raped sometime during their lives. Everywhere I went on a recent visit to the beautiful, troubled city of Cape Town, people were talking about rape. An elderly neighbor of the couple I was staying with — a woman in her 80s — had not long before been brutally raped in her home, then bound and gagged and imprisoned in a closet. Her son found her several days later, and she died soon afterward in the hospital. After hearing several not dissimilar stories and endless accounts of the endemic rape in the squatter camps and black townships, I began to see that the horrific statistic might just be true.

For the past 30 years, rape has been seen as a byproduct of social conditioning and social chaos. According to this line of reasoning, the situation in South Africa must be explained by a complex set of factors including the destruction of traditional tribal cultures, 50 years of apartheid and the aftermath of several centuries of colonial oppression. But in a new book, biologist Randy Thornhill and anthropologist Craig T. Palmer challenge such sociocultural accounts of rape and assert that it is a built-in adaptation that has evolved naturally because it confers a reproductive advantage on the men who do it.

Entitled A Natural History of Rape: Biological Bases of Sexual Coercion, the book sets out a strictly Darwinian view. Writing recently in The Sciences, the authors state their position bluntly: “We fervently believe that, just as the leopard’s spots and the giraffe’s elongated neck are the results of aeons of past Darwinian selection, so is also rape.” Elsewhere they proclaim, “There is no doubt that rape has evolutionary — and hence genetic — origins.”

As the latest salvo from the burgeoning “evolutionary psychology” movement, the Thornhill-Palmer thesis is a symptom of an increasingly heated border war — the fight over who controls the intellectual territory of human behavior. Traditionally, the study of what people do and why they do it has been the domain of the social sciences — cultural anthropologists, sociologists, psychologists and political scientists — but increasingly, evolutionary biologists are claiming that the key to human behavior lies not in our culture and social structures but in our biological makeup. In the case of A Natural History of Rape, this is more than just a rhetorical battle; our whole approach to rape prevention is potentially at stake.

Ground zero for Thornhill and Palmer is the notion that rape is a strategy for helping males to procreate. Central to their argument is a rather Aristotelian distinction between what they call “ultimate” and “proximate” causes. While they acknowledge there may be social situations that enhance the likelihood of a man raping, according to them these must always be understood as just the immediate or proximate cause of his actions. Underlying all such causes, they say, is the ultimate cause, which is a biologically built-in mechanism. In other words, whatever cultural conditions prevail, the “true” explanation for rape — and in their view the only legitimate explanation — is to be found in a man’s genes.

In support of their evolutionary view, Thornhill and Palmer point out that the majority of rape victims are young women at the peak of their fertility and hence of their child-bearing potential. Why? At great length they explain that Darwinian evolution would have selected for mechanisms in males that would target these young women for rape. Since, in their view, procreation is the “ultimate” goal driving rape, it is only logical that this sexual strategy would focus on women at their reproductive zenith.

To corroborate this view, the authors assert that studies have proved that it is women of child-bearing age who suffer the most psychological trauma in the aftermath of rape. Child rape victims and elderly victims supposedly suffer less, because although they have been physically violated, their reproductive potential has not been compromised. To quote: “The more a woman’s reproductive success would have contributed to the genetic success of her mate or her relatives in evolutionary history, the greater the suffering of those individuals is likely to be after she is raped.” It is married women in particular, they say, who suffer most from mental anguish after rape, because a married woman risks reprisal or even rejection from her husband and his relatives.

Feminist arguments against all this will be thrashed out at length elsewhere — and rightly so — but what astonishes me, as a veteran science writer and someone trained as a physicist, is what mind-bogglingly sloppy science this constitutes. To steal a quip from Anthony Lane, I’ve had bowls of spaghetti that were more tightly structured than this argument.


For a start, although Thornhill and Palmer never say so explicitly, their text is suffused with the assumption that U.S. patterns of rape are universal. A 1992 national study they cite reported that 13 percent of American women over the age of 18 say they have been raped. The same study reports that fully 29 percent of adult women surveyed were under the age of 11 at the time they were raped. Even at 13 percent, it is still far higher than those of many other societies, says Peggy Reeves Sanday, an anthropologist at the University of Pennsylvania who is an expert on rape and the author of A Woman Scorned: Acquaintance Rape on Trial and Fraternity Gang Rape.

As the author of a cross-cultural study on rape in 95 different tribal societies, Sanday stresses that its incidence varies wildly from culture to culture, and there are many societies in which rape is rare. Far from being the norm, she says, America is one of the most rape-prone of all contemporary cultures. If the biological imperative to rape is as powerful, and as universal, as Thornhill and Palmer insist, why does its frequency vary so much from culture to culture?

Mary Cameron, an anthropologist at Auburn University, points to another flaw in Thornhill and Palmer’s thesis: “It doesn’t begin to account for male-male rape, or incest,” neither of which confers any evolutionary advantage. If, according to the previously cited statistic, almost one-third of rapes are inflicted on children under 11, it is hard to see how reproductive imperatives could be responsible.

Anne Fausto-Sterling, a research biologist at Brown University, questions the very foundation of Thornhill and Palmer’s thesis: “If rape is about reproduction,” she says, “then how many rapes end in pregnancy?” According to the authors’ estimate, the figure is only about 2 percent, a very unimpressive statistic, especially given that not all pregnancies result in live births. And there could well be other explanations for the fact that the majority of rape victims are young women of peak child-bearing age. After all, most rapists are themselves young men, and they may simply be raping within their peer group.

Particularly woolly is the authors’ claim that women of child-bearing age suffer from more psychological trauma than children or elderly rape victims. Thornhill and Palmer try to convince us that this is a proven fact, but I must say I find their “evidence” entirely underwhelming. (In fact, the only study they cite as support was one done by Thornhill and his wife.) Children who have been raped can suffer a lifetime of psychological scarring (in addition to serious physical harm), and an informal poll of my female friends suggests that for many women there are few more traumatic prospects than being raped in the heightened physical vulnerability of our old age.


Trying to quantify a human being’s anguish and measure it against the suffering of another is the sort of notion that ought to make any sensible scientist run screaming from the room. It’s not just that it’s repugnant to say that a raped 7-year-old feels less pain than a raped 21-year-old — it’s also simply daft to insist that any such “objective” comparison can be made. The whole exercise is reminiscent of medieval attempts to quantify sin. Furthermore, while Thornhill and Palmer are right in saying that married rape victims may indeed fear reprisal from their husbands or relatives, the very fact that the consequences of rape are so much worse in some societies than they are in others indicates that we’re talking about cultural forces here. For example, religious women in Muslim communities probably fear this more than secular women in America; it’s the difference between a fundamentalist and a liberal value system — not biology. Do Thornhill and Palmer have any clear understanding of the distinction? They might just as well assert that black men in the Bronx feel nervous around the NYPD because they’re hard-wired to dread authority figures.

All of which raises the question of scientific standards. To quote Fausto-Sterling: “When you make a hypothesis you really need to be able to back that up with data.” Yet data is just what is missing from this book. As with so many other neo-Darwinian accounts of human behavior now being offered by proponents of the new “evolutionary psychology” movement, Thornhill and Palmer’s analysis of rape relies not on hard evidence, as they would have us believe, but on speculative flights of fancy. Stephen Jay Gould has dubbed such theories “just-so stories,” after Kipling’s fanciful tales of how the leopard got its spots and the tiger its stripes.


For most of its century-and-a-half-long history, evolutionary biology has relied on careful fieldwork, but now, says Fausto-Sterling, “what you have is this new group of ‘evolutionary psychologists’ who have very different standards of proof.” Thornhill and Palmer are part of this movement, which is in effect E.O. Wilson’s old “sociobiology” under a new name. Although still in its infancy, the movement is rapidly gaining adherents, to the consternation of many scientists — most notably Gould, who has written at length on the patent inadequacies of much of this work.

The social agenda behind A Natural History of Rape comes into clearer focus as Thornhill and Palmer claim that not only is evolutionary theory the only way to understand why men rape, but the only way to understand how to combat this heinous crime. Having offered their explanation for the former, they end their book with a suggested program for the latter. Since, according to them, all men — by their very nature — are potential rapists, they advocate that young men be required to attend rape-education courses before being granted a driver’s license. By stressing the evolutionary basis of rape, these courses would teach men where such urges come from and thus empower them to resist those urges.

Ironically, by insisting that all men are, in essence, rapists, Thornhill and Palmer are propagating a view similar to that of feminist extremists like Andrea Dworkin. The authors are aware of the parallel, and it seems to unsettle them, feminists in general being a group they despise. When feminists do make this kind of claim, the public reaction is almost universally negative — Dworkin is routinely portrayed in the media as a half-crazed, man-hating harpy — yet in Thornhill and Palmer’s hands the same proposition magically becomes acceptable. Respectable publications like The New York Times and The Sciences are now giving this idea a serious number of column inches.

However, according to Thornhill and Palmer, education about rape prevention must also extend to women. Since evolution has predisposed men to rape, women must understand these innate drives and the conditions that exacerbate them. In particular, they should realize that provocative clothing and flirtatious behavior can have violent biological consequences. Here, of course, A Natural History of Rape departs from the Dworkinian theory of who’s to blame for rape. Thornhill and Palmer strongly imply that the rapist is the one breed of criminal who, if sufficiently inflamed by miniskirts and cleavage, can’t be held entirely responsible for his crime.

Dworkin aside, Thornhill and Palmer rail against feminist views of rape throughout their book. Feminists ã and other social theorists, say the authors, are misguided, forever driven by ideology. Evolutionary psychologists like themselves, however, are supposedly clear of this “sin.”

With increasing vehemency, evolutionary psychologists and their champions (men such as E.O. Wilson and MIT’s Steven Pinker) have been casting the social sciences as impediments to a “true” understanding of human behavior. In his 1998 book, Consilience: The Unity of Knowledge, Wilson led the charge by declaring that in the coming decades most social-science departments will be made irrelevant as their subjects of inquiry are taken over by evolutionary psychology. Thornhill and Palmer reiterate such sentiments; for them, as for Wilson, there is only one legitimate source of illumination when it comes to human behavior, and that is Darwinian theory.

Perhaps it’s not surprising that in the battle for who gets to define human nature, the proponents of evolutionary psychology take no prisoners. It seems they can’t stop at simply asserting a role for their own science in understanding human behavior — they have to annihilate the competition. And it’s not hard to guess that these attacks are the covert motivation for A Natural History of Rape itself.

According to Thornhill and Palmer, social-science approaches to rape are not simply wrong-headed; by not being based on a “true” understanding of the problem, such strategies “may actually increase it.” We are offered no plausible explanation of why this may be so, but again and again we are told that as long as the “social-sciences view of rape” prevails, the problem will never be solved. Their hearts on their sleeves, the authors write: “In addressing the question of rape, the choice between the politically constructed answers of social science and the evidentiary answers of evolutionary biology is essentially a choice between ideology and knowledge. As scientists who would like to see rape eradicated from human life, we sincerely hope that truth will prevail.”

But what is “truth”? For Thornhill and Palmer, as for most evolutionary psychologists, it is a Platonic reality untainted by social or political force, a reality that only “pure” and “unadulterated” science can discover. But how “pure” can science ever be when it’s dealing with such complex and politically charged issues as rape? And how “scientific” can Thornhill and Palmer’s own assertions be when they’re based on interpretations of data that can’t be subjected to rigorous testing? The history of biology — when the science has been extrapolated to explain human behavior — is riddled with ideology posing as science, as Fausto-Sterling’s Myths of Gender and her current book, Sexing the Body, as well as Gould’s The Mismeasure of Man, have shown. Ideology posing as science was also at the heart of the eugenics movement — both here in the U.S. and more devastatingly in Nazi Germany. To paraphrase philosopher of science Donna Haraway, biology is politics by another name.


The ideological proof in Thornhill and Palmer’s pudding is clear from the fact that although they devote several chapters to berating social scientists’ understanding of rape, they give us no serious analysis whatsoever of the actual rape-prevention programs and strategies arising from that understanding. With mantralike frequency, they tell us that current approaches to rape prevention are wrong, but by what criteria?

It only stands to reason that before you dismiss a program as ineffective, you should check its results to make sure that it doesn’t actually work. But despite the cloak of disinterested, objective science Thornhill and Palmer have wrapped around their work, they’re not really interested in the facts or a careful, cautious weighing of all evidence. The powerful irrational emotions underlying A Natural History of Rape and other similarly reductionist theories indicate how close the mania for evolutionary psychology comes to religious fundamentalism. While the Christian fundamentalist takes the Bible as his foundational text, insisting on the most literal interpretation, so these new scientific fundamentalists insist on the most doggedly literal interpretation of their chosen “text.” Here the “words” are not those of the Hebrew scriptures, but the codons of the DNA chain — which take on for them an almost divine status.

It goes without saying that Thornhill and Palmer’s book does women an immense disservice. But even more depressing is the disservice these authors do to science. Over the past decade the once-golden image of science has been sorely tarnished, and there is a growing perception that scientists are an arrogant elite, many of whom are out of touch with ordinary people’s lives. When books like this offer up such a sloppy, illogical and downright lazy analysis of such a complex social problem, they only help to fuel that perception. If this is the kind of rubbish that “science” turns out, is it any wonder people are turning away?

Fortunately, the brand of Z-grade analysis that reigns in A Natural History of Rape is not indicative of the majority of scientific thinking, or of evolutionary thinking, and there are many scientists who find the current abuses of evolutionary psychology as irksome as I do. Those of us who love science and believe in its potential have an obligation to expose this nonsense for what it is. If we don’t, then who will?


A NATURAL HISTORY OF RAPE: Biological Bases of Sexual Coercion By RANDY THORNHILL and CRAIG T. PALMER | MIT Press | 243 pages
$29 hardcover

Margaret Wertheim is a regular contributor to the Weekly. This article first appeared in Salon magazine, at An online version remains in the Salon archives. Reprinted with permission.

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