Deviant sex, almost by definition, is bound to gross out more people than normal sex—but disgust doesn’t justify hatred.

The following is an excerpt from PERV: The Sexual Deviant in All of Us by Jesse Bering, published October 8, 2013 by Scientific American / Farrar, Straus and Giroux, LLC. Copyright © 2013 by Jesse Bering. All rights reserved. 

You are a sexual deviant. A pervert, through and through.

Now, now, don’t get so defensive. Allow me to explain. Imagine if some all-powerful arm of the government existed solely to document every sexual response of every private citizen. From the most tempestuous orgasmic excesses, to the slightest twinges of genitalia, to unseen hormonal cascades and sub-cranial machinations, not a thing is missed. Filed under your name in this fictional scientific universe would be your very own scandalous dossier, intricate and exhaustive in its every embarrassing measurement of your self-lubricating loins. What’s more, the records in this nightmarish society extend all the way back to your adolescence, to the days when your desires first began to simmer and boil. I’d be willing to bet that buried somewhere in this relentless biography of yours is an undeniable fact of your sex life that would hobble you instantaneously with shame should the wrong individual ever find out about it.

To break the ice, I’ll go first. And how I wish one of my first sexual experiences were as charming as inserting my phallus into a warm apple pie. Instead, it involves pleasuring myself to an image from my father’s old anthropology textbook. This isn’t even as admirable as those puerile stories about a teenage boy masturbating to some National Geographic–like spread of exotic naked villagers breast-feeding or shooting blow darts in the Amazon. No, it wasn’t anything like that. For me, the briefest of heavens could instead be found in an enormous and hairy representative of the species Homo neanderthalensis. I can still see the lifelike rendering now. The Neanderthal was shown crouching down, pink gonads dangling teasingly between muscular apish thighs, while with all his cognitive might this handsome, grunting beast tried desperately to light a fire in a cobbled pit to warm his equally hirsute family (what looked to be a perplexed woman from whose furry breasts a baby feverishly suckled). The Neanderthal was in fact too brutish for my tastes, but in those pre-Internet days he was the only naked man I had at my fingertips. Well, the only naked hominid, anyway. One must work with the material one has.

So there, I said it. In my adolescence, I derived an intense orgasm (or twenty) from fantasizing about a member of another species. (In my defense, it was a closely related species.) You may have to rack your brains for some similarly indecent memory, or then again, maybe all you need to do is roll over in bed this morning to remind yourself of the hairy specimen of a creature that you brought home last night. Either way, chances are there’s something gossip-worthy in your own sexual past. Maybe it’s not quite as odd as mine. But I’m sure it’s suitably humbling for present purposes. What makes us all the same is our having had certain private moments that could get us blackmailed.

Granted, most of us will never share our own lurid tidbits about our most unusual masturbatory mental aids or the fact that there’s a distinct possibility we had the tongue of a Sasquatch in our nether regions last night (or ours in its). What usually gets out is only what we want others to know. That’s perfectly understandable. We have our reputations to consider. I might never be allowed again into my local museum for fear I’ll debase one of the caveman mannequins, for instance. The problem with zipping up on our dirtiest little secrets, however, is that others are doing exactly the same thing, and this means that the story of human sexuality that we’ve come to believe is true is, in reality, a lie. What’s more, it’s a very dangerous lie, because it convinces us that we’re all alone in the world as “perverts” (and hence immoral monsters) should we ever deviate in some way from this falsely conceived pattern of the normal. A lot of human nature has escaped rational understanding because we’ve been unwilling to be completely honest about what really turns us on and off—or at least what’s managed to do the trick for us before. We cling to facades. We know one another only partially. Much of what lies ahead, therefore, concerns what you don’t want the rest of the world to know about your sexuality. But relax, that will be our little secret.

Again, however, I’d urge you to come clean in the confession booth of your own mind. And really, just a small unburdening of your erotic conscience will do for now. Reach far, far into the abyss of your wettest of dreams. Or perhaps it was only a fleeting, long-forgotten secretion, a lingering gaze misplaced, a furtive whiff of an object redolent with someone you once craved, a wayward click of the mouse, a hypothalamic effervescence that made you tingle down below. Nevertheless, even if you settle on one of these relatively minor examples, each embodies a corporeal reality specific to you … a “shocking,” incontrovertible deed of physiology or an outright commission of lust that you’ve never shared with a single person, maybe not even yourself until now.

Whatever it is, once it’s laid bare for all the world to see in your declassified government report, a faultless testimony in inerasable ink, this unique venereal data point will undoubtedly register in the consciousness of someone, somewhere out there as evidence of your sexual deviance, or perhaps even your criminality. Just look around you or think of all the people you know. In the unforgiving lair of another’s critical eyes, you have now been transformed irreversibly into a filthy, loathsome pervert. And that’s the feeling, this fetid social emotion of shame, that I want you to keep in the back of your mind as you read this book. We’re going to get to the bottom of where it comes from, and we’re going to do our best to smother it with reason in our efforts to stop it from hurting you and others in the future.

This feeling doesn’t just make you a guilty pervert; more important, it makes you a human being. Blue-haired grandmothers, somnambulant schoolteachers, meticulous bankers, and scowling librarians, they’ve felt it too, just like you. We tend not to think of others as sexual entities unless they’ve aroused us somehow, but with the exception of those people spared by certain chromosomal disorders, we’re all innately lewd organisms. That’s easy to grasp in some abstract sense. But try putting it into practice. The next time you’re at the grocery store and the moribund cashier with the underbite and the debilitating bosom sweeps your bananas across the scanner, think of precisely where those uncommonly large hands have been. How many men or women—including her—have those seemingly asexual appendages brought ineffable bliss? This isn’t an exercise in the grotesque; it’s a reminder of your animal humanity. A concupiscent beast has roamed under all skins … even that of the grumpy checkout lady.

Yet the best-kept secret is even bigger than this unspoken universality. It’s this: exploring the outer recesses of desire by using the tools of science is a pinnacle human achievement. It’s not easy, but digging into the darkest corners of our sexual nature (that is to say, our “perversions”) can expose what keeps us from making real moral progress whenever the issues of equality and sexual diversity arise. With each defensive layer we remove, the rats therein will flee at the daylight falling at their feet, and the opportunity to eradicate such a pestilence of fear and ignorance makes the excavation of our species’s lascivious soul worth our getting a little dirty along the way.

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We’re not the first to use the grimier realities of human sexuality to grease our way into some deeper truths. They may not have been scientists, but many artists and writers have touched on related psychological processes that were insightful and even foretold future research directions. In his 1956 play, The Balcony, for example, the French playwright Jean Genet showed how people who are inebriated by desire experience cognitive distortions motivating them to engage in behaviors that in a less aroused state of mind they’d perceive as obscene. Genet’s story revolves around the daily affairs of a busy brothel in a town on the brink of war. Run by an astute madam named Irma, the whorehouse is a sanctuary in which high-profile local officials are free to drain away their carnal excess. Once they’ve done so, they can get on with the business of being “normal” and respectable public figures defending the town from the enemy. Irma’s house of illusions has come to serve some colorful patrons, including the town judge, who feigns to “punish” a naughty prostitute, a bishop who pretends to “absolve the sins” of a demure penitent, and a general who enjoys riding his favorite (human) horse. “When it’s over, their minds are clear,” Irma reflects after these men visit her establishment. “I can tell from their eyes. Suddenly they understand mathematics. They love their children and their country.” The lustful human brain, Genet understood in a way that contemporary scientists are just now starting to fully grasp by using controlled studies in laboratory settings, is simply not of the same world as that of its sober counterpart.

One point I’d like to make crystal clear at the outset of our journey is that understanding is not the same as condoning. Our sympathies can take us only so far, and entering other minds isn’t pleasant when it comes to certain categories of sex offenders. Furthermore, it’s one thing to wax theoretical about sexual deviance, but another altogether to be the victim of sex abuse in real life or to know that someone we love, especially a child, has been harmed. Yet while it’s a common refrain to liken the most violent sex offenders to animals, whether we like it or not, even the worst of them are resoundingly human. As unsettling as it can sometimes be to lean in for a closer look, their lives can offer us valuable lessons about what can go wrong in the development of a person’s sexual identity and decision making. “I consider nothing that is human alien to me,” said the Roman philosopher Terence. I feel the same way. And Terence’s credo is one I intend to adhere to closely when it comes to some of the characters we’ll be meeting along the way.

I’ll do my best, anyway. For while there’s no doubt that the most terrible rapists, child molesters, and other more banal classes of sex offenders were around in his day, Terence didn’t know of the hundreds of extravagant “paraphilias” (or sexual orientations toward people or things that most of us wouldn’t consider to be particularly erotic) that scientists would eventually discover when he confidently uttered those words more than two thousand years ago. Even he might have had trouble finding common ground with, say, “teratophiles,” those attracted to the congenitally deformed, or “autoplushophiles,” who enjoy masturbating to their own image as cartoonlike stuffed animals.

Understanding the etymology of the word “pervert,” oddly enough, can help us to frame many of the challenging issues to come. Perverts weren’t always the libidinous bogeymen we know and loathe today. Yes, sexual mores have shifted dramatically over the course of history and across societies, but the very word “pervert” once literally meant something else entirely than what it does now. For example, it wouldn’t have helped his case, but the peculiar discovery that some peasant during the reign of Charles II used conch shells for anal gratification or inhaled a stolen batch of ladies’ corsets while touching himself in the town square would have been merely coincidental to any accusations of his being perverted. Terms of the day such as “skellum” (scoundrel) or reference to his “mundungus” (smelly entrails) might have applied, but calling this man a “pervert” for his peccadilloes would have made little sense at the time.

Linguistically, the sexual connotation feels so natural. The very ring of it—purrrvert—is at once melodious and cloying, producing a noticeable snarl on the speaker’s face as the image of a lecherous child molester, a trench-coated flasher in a park, a drooling pornographer, or perhaps a serial rapist pops into his or her head. Yet as Shakespeare might remind us, a pervert by any other name would smell as foul.

For the longest time, in fact, to be a pervert wasn’t to be a sex deviant; it was to be an atheist. In 1656, the British lexicographer Thomas Blount included the following entry for the verb “pervert” in his Glossographia (a book also known by the more cumbersome title A Dictionary Interpreting the Hard Words of Whatsoever Language Now Used in Our Refined English Tongue): “to turn upside down, to debauch, or seduce.” All of those activities occur in your typical suburban bedroom today. But it’s only by dint of our post-Victorian minds that we perceive these types of naughty winks in the definition of a term floating around the old English countryside. In Blount’s time, and for several hundred years after he was dead and buried, a pervert was simply a headstrong apostate who had turned his or her back on the draconian morality of the medieval Church, thereby “seducing” others into a godless lifestyle.

Actually, even long before Blount officially introduced perverts to the refined English-speaking world in all their heathen fury, an earlier form of the word appeared in the Catholic mystic Boethius’s Consolation of Philosophy in the year 524.* Like Blount’s derivation, the mystic’s pervertere was a bland “turning away from what is right.” Given the context of Christian divinity in which Boethius’s treatise was written, it’s clear that “against what is right” meant much the same then as it does for God-fearing people today, which is to say, against what is biblical.

So if we applied this original definition to the present iconoclastic world of science, one of the world’s most recognizable perverts would be the famous evolutionary biologist Richard Dawkins. As the author of The God Delusion and an active proselytizer of atheism, Dawkins encourages his fellow rationalists to “turn away from” canonical religious teachings. (I’ve penned my own scientific atheistic screed, so I’m not casting stones. I’m proudly in possession of a perverted nature that fits both the archaic use of the term, due to my atheism, and its more recent pejorative use, due to my homosexuality.)

Only at the tail end of the nineteenth century did the word “pervert” first leap from the histrionic sermons of fiery preachers into the heady, clinical discourses of stuffy European sexologists like the ones you’ll be introduced to soon. And it was a long time after that still before “pervert”—or “perv” if we’re being casual—became slang for describing the creepy, bespectacled guy up the road who likes to watch the schoolgirls milling about the bus stop in their miniskirts while he sips tea on his front porch.

This semantic migration of perverts, from the church pews to the psychiatric clinic to the online comments section of news stories about sex offenders, hasn’t occurred without the clattering bones of medieval religious morality dragging behind. Notice the suffix -vert means, generally, “to turn”: hence “convert” (to turn to another), “revert” (to turn to a previous state), “invert” (to turn inside out), “pervert” (to turn away from the right course), and so on. But of all these related words, “pervert” alone has that devilishly malicious core—“a distinctive quality of obstinacy,” notes the psychoanalyst Jon Jureidini, “petulance, peevishness … self-willed in a way that distinguishes it from more ‘innocent’ deviations.” A judge accusing someone of “perverting the course of justice” is referring to a deliberate effort to thwart moral fairness. Similarly, with the modern noun form of “pervert” being synonymous with “sex deviant,” the presumption is that he (or she) is a deviant by his own malicious design. That is, he is presumed to have willfully chosen to be sexually aberrant in spite of such a decision being morally wrong.

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It’s striking how such an emotionally loaded word, one that undergoes almost no change at all for the first thousand years of its use in the English language, can almost overnight come to mean something so very different, eclipsing its original intent in its entirety. So how, exactly, did this word “pervert” go from being a perennial reference to the “immoral religious heretic” to referring to the “immoral sexual deviant”?

The answer to this riddle can be found in the work of the Victorian-era scholar Havelock Ellis of South London, who is credited with popularizing the term in describing patients with atypical sexual desires back in 1897. Although earlier scholars, including the famous Austro-German psychiatrist Richard von Krafft-Ebing, regarded by many as the father of studies in deviant sexuality, preceded Ellis in sexualizing the term, Ellis’s accessible writing in the English language found a wider general audience and ultimately led to the term being solidified this way in the common vernacular. The provenance of the term in Ellis’s work is still a little hard to follow, because he initially uses “perverts” and “perversions” in the sense of sexual deviancy in the pages of a book confusingly titled Sexual Inversion. Coauthored by the gay literary critic John Addington Symonds and published posthumously, the book was a landmark treatise on the psychological basis of homosexuality. “Sexual inversion,” in their view, reflected homosexuality as being a sort of inside-out form of the standard erotic pattern of heterosexual attraction. That part is easy enough to understand. Where Ellis and Symonds’s language gets tricky, however, is in their broader use of “sexual perversions” to refer to socially prohibited sexual behaviors, of which “sexual inversion” was just one. (Other classic types of perversions included polygamy, bestiality, and prostitution.) The authors adopted this religious language not because they personally believed homosexuality to be abnormal and therefore wrong (quite the opposite, since their naturalistic approach was among the first to identify such behaviors in other animals) but only to note how it was so salient among the categories of sexuality frequently depicted as “against what is right” or sinful.* Also Symonds, keep in mind, was an out and proud gay man. The word was merely an observation about how homosexuals (or “inverts”) were regarded by most of society.

Interestingly enough, the scientist of the pair, and the one usually credited with christening gays and lesbians as sex “perverts,” had his own unique predilections. Havelock Ellis’s “urophilia,” which is a strong sexual attraction to urine (or to people who are in the process of urinating), is documented in his various notes and letters. In correspondence with a close female acquaintance, Ellis chided the woman for forgetting her purse at his house, adding saucily, “I’ve no objection to your leaving liquid gold behind.” He gave in to these desires openly and even fancied himself a connoisseur of pisseuses, writing in his autobiography: “I may be regarded as a pioneer in the recognition of the beauty of the natural act in women when carried out in the erect attitude.” In his later years, this “divine stream,” as he called it, proved the cure for Ellis’s long-standing impotence. The image of an upright, urinating woman was really the only thing that could turn him on. And he was entirely unashamed of this sexual quirk: “It was never to me vulgar, but, rather, an ideal interest, a part of the yet unrecognised loveliness of the world.” On attempting to analyze his own case (he was a sexologist, after all), Ellis concluded, “[It’s] not extremely uncommon … it has been noted of men of high intellectual distinction.”* He was also convinced that men with high-pitched voices were generally more intelligent than baritones. That Ellis himself was a rare high tenor might have had something to do with that curious hypothesis as well.

Ellis was among a handful of pioneering sexologists in the late nineteenth and early twentieth centuries who’d set out to tease apart the complicated strands of human sexuality. Other scholars, such as Krafft-Ebing, as well as the German psychiatrist Wilhelm Stekel and, of course, the most famous psychoanalyst of all, Sigmund Freud, were similarly committed to this newly objective, amoral empirical approach to studying sexual deviance. Their writings may seem tainted with bias to us today, and in fact they are, but they also display a genuine concern for those who found themselves, through no doing or choice of their own, being aroused in ways that posed serious problems for them under the social conditions in which they lived.

It’s worth bearing in mind, for instance, that Ellis and Symonds’s Sexual Inversion was written on the heels of Oscar Wilde’s sensationalized 1895 gross indecency trials, in which (among other things) that great Dubliner wit was publicly accused of cavorting with a fleet of boys and men in a series of racy homosexual affairs. Taking the stand at London’s Old Bailey courthouse, where the father of his petulant young British lover, Lord Alfred Douglas, had brought charges against him, Wilde famously referred to homosexuality as “the love that dare not speak its name.” The jury sentenced him to two years of hard labor for the crime of sodomy. (Incidentally, although consensual anal sex is no longer a crime in the United Kingdom, the fact that forcible anal penetration, among other acts, is still officially called “sodomy”—as in Sodom and Gomorrah—throughout the industrialized world even today shows just how deeply an antiquated religious morality is embedded and tangled up in our modern sex crime laws.)

What often gets overlooked in Wilde’s account is the fact that “the love that dare not speak its name” referred to a specific type of homosexual relationship. Sexologists today would label Wilde’s well-known affinities as evidence of his “ephebophilia” (attraction to teens or adolescents). Wilde’s intent in the phrase being especially applicable to courtships between men and teenage boys is clear when one reads his full elaboration on the stand, where he goes on to describe this unspeakable love:

As there was between David and Jonathan, such as Plato made the very basis of his philosophy, and such as you find in the sonnets of Shakespeare. It is that deep, spiritual affection that is as pure as it is perfect. It dictates and pervades great works of art like those of Michelangelo … It is beautiful, it is fine, it is the noblest form of affection. There is nothing unnatural about it. It is intellectual, and it repeatedly exists between an elder and a younger man, when the elder man has intellect, and the younger man has all the joy, hope and glamour of life before him. That it should be so, the world does not understand. The world mocks at it and sometimes puts one in the pillory for it.

Wilde’s description of such a mutually beneficial, intergenerational romance is ironic today, because “the love that dare not speak its name” is now more unutterable than ever. The modern ephebophilic heirs of Wilde, Plato, and Michelangelo are not only mocked and pilloried but branded erroneously, as we’ll see later, as “pedophiles.”

Much like Wilde facing his detractors, the early sexologists found themselves confronted by angry purists who feared that their novel scientific endeavors would open the door to the collapse of cherished institutions such as marriage, religion, and “the family.” Anxieties over such a “slippery slope effect” have been around for a very long time, and in the eyes of these moralists an objective approach to sexuality threatened all that was good and holy. Conservative scholars saw any neutral evaluation of sex deviants as a dangerous stirring of the pot, legitimizing wicked things as “natural” variants of behavior and leading “normal” people into embracing the unethical lifestyles of the degenerate. Merely giving horrific tendencies such as same-sex desires their own proper scientific names made them that much more real to these moralists, and therefore that much more threatening. To them, this was the reification of sexual evil. In a scathing review of Sexual Inversion, for instance, a psychiatrist at the Boston Insane Hospital named William Noyes chastised the authors for “adding three hundred more pages to a literature already too flourishing … Apart from its influence on the perverts themselves no healthy person can read this literature without a lower opinion of human nature, and this result in itself should bid any writer pause.”

Looking back now, it becomes evident that Ellis and Symonds’s careful distinction between homosexual behavior and homosexual orientation was an important step in the history of gay rights. It may seem like common sense today, but for the first time ever homosexuality was being widely and formally conceptualized as a psychosexual trait (or orientation), not just something that one “did” with members of the same sex. This watershed development in psychiatrists’ way of thinking about homosexuality had long-lasting positive and negative implications for gays and lesbians. On the positive side, homosexuals were no longer perceived (at least by experts) as fallen people who were simply so immoral and licentious that they’d even resort to doing that; instead, they were seen as having a psychological “nature” that made them “naturally” attracted to the same sex rather than to the opposite sex.

On the negative side, this newly recognized nature was also regarded as inherently abnormal or flawed. With their inverted pattern of attraction, homosexuals became perverts in essence, not just louses dabbling in transgressive sex. Whether or not they ever had homosexual sex, such people were now one of “them.” Also, once homosexuality was understood to be an orientation and not just a criminal behavior, it could be medicalized as a psychiatric “condition.”* For almost a hundred years to follow, psychiatrists saw gays and lesbians as quite obviously mentally ill. And just as one would treat the pathological symptoms of patients suffering from any mental illness, most clinicians believed that homosexuals should be treated for their unfortunate disorder. I’ll come back to “conversion therapy” in later chapters, but needless to say, such treatments, in all their shameful forms, certainly didn’t involve encouraging gays and lesbians to be themselves.

The die had also been cast for the disparaging term “pervert” and its enduring association with homosexuality. Not so long ago, some neo-Freudian scholars were still interpreting anal intercourse among gay men as an unconscious desire in the recipient to nip off the other’s penis with his tightened sphincter. “In this way, which is so characteristic of the pervert,” mused the influential psychiatrist Mervin Glasser in 1986, “he [is] trying to establish his father as an internal object with whom to identify, as an inner ally and bulwark against his powerful mother.” That may sound as scientific to us today as astrology or etchings on a tarot card, but considering that Glasser wrote this thirteen years after the American Psychiatric Association removed homosexuality from its list of mental disorders, it shows how long the religious moral  connotations stuck around even in clinical circles. Glasser’s bizarre analysis of “perverts” is the type of thing that gay men could expect to hear if they ever sought counseling for their inevitable woes from living in a world that couldn’t decide if they were sick or immoral, so simply saw them as both.

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Today the word “pervert” just sounds silly, or at least provincial, when it’s used to refer to gays and lesbians. In a growing number of societies, homosexuals are slowly, if only begrudgingly, being allowed entry into the ranks of the culturally tolerated. But plenty of other sexual minorities remain firmly entrenched in the orientation blacklist. Although, happily, we’re increasingly using science to defend gays and lesbians, deep down most of us (religious or not) still appear to be suffering from the illusion of a Creator who set moral limits on the acceptable sexual orientations. Our knee-jerk perception of individuals who similarly have no choice over what arouses them sexually (pedophiles, exhibitionists, transvestites, and fetishists, to name but a few) is that they’ve willfully, deliberately, and arrogantly strayed from the right course. We see them as “true perverts,” in other words. Whereas gays and lesbians are perceived by more and more people as “like normal heterosexuals” because they didn’t choose to be the way they are, these others (somehow) did.

A subtle form of this flawed logic can even be found in the reasoning of some atheistic evolutionary biologists. When weighing in on the marriage equality debate or on other gay rights issues, many scholars like to mention the simple fact that homosexual acts are common in other species, too. This is to say, “Oh, relax, everyone, gays and lesbians are fine because, look, they really aren’t that weird in the grand scheme of things.” There’s good emotional currency in animal comparisons, and I like this tack very much for its rhetorical effects. Yet it’s fundamentally wrong, because it simultaneously invokes a moral judgment against those whose sexual orientations are not found in other animals. Furthermore, even if we were indeed the lone queer species in an infinite universe of potentially habitable planets, it’s unclear to me how that would make marriage between two gay adults in love with each other less okay.

Same-sex behaviors in other species are interesting in their own right. But are we humans really that lost in the ethical wilderness that we’re actually seeking guidance from monkeys, crawfish, and penguins about the acceptable use of our genitals? We engage in the same questionable reasoning when citing other nonmonogamous species to support our views on polyamorous (or “open”) relationships (this was in fact a message central to the popular book Sex at Dawn by Christopher Ryan and Cacilda Jethá).

Even though we may be operating with the most humane intentions, when we’re thinking about sex and morality, it’s all too easy to fall prey to a philosophical error called the naturalistic fallacy. In effect, the naturalistic fallacy assumes that that which is natural is therefore okay, good, or socially acceptable and that which is unnatural is, in turn, bad and unacceptable. Those who use examples of same-sex liaisons in other species to justify the social acceptance of gays and lesbians are every bit as guilty of the naturalistic fallacy as the religious conservatives who perceive some sort of “obviousness” in these behaviors being morally wrong due to their “unnaturalness.” After all, sex acts with reproductively immature juveniles and forced copulation are also commonly found in nature—in fact, much more so than homosexuality. Yet these more impolite details about the sex lives of other species haven’t led to many moral arguments (or at least persuasive ones) for human adults having sex with children or men raping women. And they shouldn’t. But we need to be careful here, because in cherry-picking features of the natural world to defend one social category—in this case, gays and lesbians—we risk shaking the whole tree.

This problem of the naturalistic fallacy is even more apparent when the “acceptable” form of human sexual deviance occurs alongside “unacceptable” forms in the very same species. Bonobo chimpanzees (Pan paniscus) are one of the most frequently mentioned examples of another primate exhibiting a natural tendency to engage in homosexual acts and to have multiple sexual partners. Given our close genetic relationship with bonobos (we share around 98.6 percent of our DNA with them), they’re often used to showcase the “naturalness” of human homosexuality and the “unnaturalness” of human monogamy. These apes are most notorious for their passionate displays of “GG-rubbing” between females (genito-genital friction involving two female bonobos ecstatically rubbing their clitorises together), but mutual masturbation between males is also common. Such homoerotic encounters are believed to be central to the bonobo’s relatively nonaggressive nature, in that sex is used as a sort of peace offering for dialing down rising social tensions in the group before things turn violent. As the primatologist Frans de Waal notes, what’s especially interesting is that bonobos’ “sociosexual behaviors” would get humans arrested. (This is clear from his article titled “Sociosexual Behavior Used for Tension Regulation in All Age and Sex Combinations Among Bonobos,” which was published in the journal Pedophilia.) Not only are “consenting adult bonobos” being “naturally” gay and promiscuous with each other, but you’ll also find, for example, adult male bonobos “naturally” fondling immature males alongside adult female bonobos “naturally” mouthing the genitals of juvenile females.

When religious or social conservatives commit the naturalistic fallacy, by contrast, the issue of procreation usually takes center stage and the philosophical error is embarrassingly salient. The trouble with confusing morality with reproduction applies equally to any sex act that can’t produce offspring, but it’s most commonly seen, unsurprisingly, in arguments against homosexuality. Many social conservatives enjoy pointing out to those of us who just can’t seem to grasp these more challenging aspects of biology that whereas having intercourse with the opposite sex can produce offspring, having intercourse with the same sex cannot. This is usually extrapolated to mean that gay sex is obviously unnatural, and so it’s obviously just plain wrong (translation: arrogantly ignores God’s intentional design).

Given that nature is mechanistic and amoral, and not the product of intelligent forethought, this entire position is a nonstarter. To draw from the assembly-line principles of reproductive biology any moral directive or prescription for what human beings should and should not do with their genitalia is to assume that a Creator intentionally engineered our reproductive anatomies. That pre-Darwinian view—that a preconceiving mind is needed to account for the evolution of our body parts and that this divinely penned blueprint should in turn dictate our social behaviors—lies at the malformed heart of the religious argument against homosexuality (one that’s usually expressed in the form of some awful rendition of the “Adam and Steve” fundamentalist refrain).

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We’ve become so focused as a society on the question of whether a given sexual behavior is evolutionarily “natural” or “unnatural” that we’ve lost sight of the more important question: Is it harmful? In many ways, it’s an even more challenging question, because although naturalness can be assessed by relatively straightforward queries about statistical averages—for example, “How frequently does it appear in other species?” and “In what percentage of the human population does it occur?”—the experience of harm is largely subjective. As such, it defies such direct analyses and requires definitions that resonate with people in vastly different ways. When it comes to sexual harm in particular, what’s harmful to one person not only is completely harmless to another but may even, believe it or not, be helpful or positive. If the supermodel Kate Upton were to walk into my office right now and tie me to my chair before doing a slow striptease and depositing her vagina in my face, I think I’d require therapy for years. But if this identical event were to happen to my heterosexual brother or to one of my lesbian friends, I suspect their brains would process such a “tragic” experience very differently. (And that of my not-very-amused sister-in-law would see my brother’s encounter with said vagina differently still.)

It’s not just overt sex acts that people experience differently in terms of harm but also sexual desires. For the religiously devout, this entire conversation is a lost cause. But once one abandons the notion that one can “commit” a sin by thinking a thought, it becomes quite clear that sexual desires—no matter how deviant—are intrinsically harmless to the subject of a person’s lust, at least in the physical sense. Mental states are “mere breath on the air,” as the philosopher Jean-Paul Sartre once wrote. Sexual desires can, of course, be thought bubbles with thorns and wreak havoc on a person’s own well-being (especially when they occur in the heads of those convinced such thoughts come from the Devil and yet they just can’t stop having them). Still, it’s only when this “mere breath on the air” is manifested in behavior that harm to another person may or may not occur.

Treating an individual as a pervert in essence, and hence with a purposefully immoral mind, because his or her brain conjures up atypical erotic ideas or responds sexually to stimuli that others have deemed inappropriate objects of desire, is medieval in both its stupidity and its cruelty. It’s also entirely counterproductive. Research on the “white bear effect” by the social psychologist Daniel Wegner has shown, for instance, that forcing a person to suppress specific thoughts leads to those very thoughts invading the subject’s consciousness even more than they otherwise would. (Whatever you do, don’t—I repeat, do not—think about a white bear during the next thirty seconds.)

Our moral evaluations should fall upon harmful sexual actions with the heaviest of thuds, but not upon a pituitary excretion that happens to morph into an ethereal image in the private movie theater of someone’s mind. It’s easier to agree with that statement in principle than it is to put it into practice, however. Simply having knowledge of another person’s deviant desires can interfere with our ability to be so logical. If somehow you became aware that your friendly middle-aged neighbor, the one with the Honda Accord, the white picket fence, and the adoring golden retriever, derives intense sexual gratification by masturbating to violent rape fantasies, and that the mere sight of a horse’s penis in one of her many glossy copies of Equus can bring the cheery, rosy-cheeked woman who works at the bakery up the road to a mind-numbing climax, would this alter your perception of them as respectable members of your community? Neither one, to your knowledge, has ever harmed a living soul due to his or her deviant desires (nor is there any reason to think they’d ever act on them, since they seem to have successfully refrained from doing so up to this point), yet it’s still hard to keep from pulling out our moral yardstick and applying it to their “mere breath on the air.”

In the real world, one reason we mistakenly conflate sexual desires and sexual behaviors in our moral evaluations of others is that the actual distance between the two can be measured by the neuron. That is to say, while it’s true that sexual desires don’t always turn into overt actions, it’s also the case that behaviors are strongly motivated by what’s on a person’s mind. Using our knowledge of a person’s sexual desires to morally judge him or her constitutes a philosophical error, but from an evolutionary perspective, it’s the sort of bad philosophy that often leads to adaptive social decision making. Even if his history is unimpeachable, declining an invitation from that neighbor of yours with the violent rape fantasies to join him for a romantic dinner at his place tomorrow night—just the two of you—seems prudent if you’re an attractive female. And assuming I had one, I’m afraid that even I’d be slightly reluctant to let the horse-loving bakery worker near my impressive stallion.

This better-safe-than-sorry bias is morally rational (it’s designed to protect ourselves or those we care about from harm), but it’s not morally logical (it’s a form of prejudice against someone on the basis of his or her sexual nature, not a decision based on anything the person has actually done). When it comes to high-risk social decisions such as who’s going to babysit the children or whether or not to go out on a date with someone you barely know, negative stereotypes can have adaptive utility. But just because something is adaptive doesn’t mean it’s ethically defensible. (Assuming so would be to commit the naturalistic fallacy.) After all, it works the same way for any minority social category. Whether it’s the color of one’s skin, how much a person weighs, or the particular accent a person speaks with, negative stereotypes are shortcuts in our social reasoning that crop up mostly under time pressures and as the stakes rise. In the case of those with deviant sexual desires and our attempts to avoid harm, caution may be warranted, but we also shouldn’t follow our emotionally driven intuitions so blindly that we’re wholly unaware of our failure in moral logic. Overgeneralizing the frightening attributes of the most negative examples of a hidden social category (such as a religious denomination or a sexual orientation) to everyone in that category leads to disturbing effects in which we become overly paranoid about the unseen monsters in our midst. In sociological terms, we submit to “moral panic.” Since unsavory carnal desires can’t be easily detected, everyone is potentially now one of “those people.”

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If a measure came up on the voting ballot today for the preemptive extermination of pedophiles, I’ve no doubt that it would pass by a landslide. Most people, I suspect, would reason that since pedophiles are intrinsically evil, eradicating them this way is in the best interest of society. There was once a similar approach to dealing with sexual deviancy in seventeenth-century New England. You’ve heard of the witch hunts in Salem, but I’m guessing you’re not as familiar with the pig-man hunts of New Haven. The most troubling sex fiends of those days weren’t pedophiles (the age of consent in the colonies was ten, if that tells you anything) but men secretly in league with the Devil to impregnate barnyard animals. The fear was that the resulting malevolent offspring (called “prodigies”—my, how the meaning of that word has changed over time) would silently infiltrate the fledgling America and muck it all up with evil for the God-fearing folk. The settlers had gotten this strange idea from the teachings of the violently prudish medieval scholar Thomas Aquinas, who coined the term “prodigy” to refer to any hybrid creature sprung from the loins of another species but borne of human seed. According to him, prodigies could also be conceived through sex with atheists (a.k.a. perverts), but it seems there were far fewer of those milling about the colonies than solicitous swine.

It’s unclear if any of the early Americans I’m about to describe were what today’s sexologists would call “zoophiles,” individuals who are more attracted to nonhuman animals than to human ones. They may have merely used members of other species as surrogates for human partners in obtaining sexual gratification (as half of all “farm-bred” adolescent males have done, according to Alfred Kinsey in 1948), or they could have been falsely accused of such acts altogether. Yet some modern scientists believe that zoophilia is a genuine sexual orientation represented by as much as a full 1 percent of the human population. Just as it’s impossible for nonzoophiles to become aroused by the steaming, mottled member of a Clydesdale or by a German shepherd rolling over for a tummy rub, “true zoophiles” can’t get (easily) turned on by human beings. One such man—a physician from suburbia, incidentally—could only consummate his marriage to a woman by closing his eyes and imagining his new bride as a horse. Strangely enough, the marriage didn’t last.

Centuries ago in the newfound colony of Plymouth, zoophilia was obviously not a known sexual orientation (again, the psychosexual construct of an “orientation” wouldn’t appear until the late nineteenth century). But the hysteria over Satan’s prodigal litters reached dramatic heights with the 1642 trial of a sixteen-year-old boy named Thomas Granger. This randy adolescent had been indicted for taking indecent liberties with what seems an entire stable full of animals, including “a mare, a cow, two goats, five sheep, two calves and a turkey.” I realize the turkey part is a bit distracting (and how one goes about having sex with a large clawed bird is better left unexamined), but even more remarkable is the legal diligence and sobriety with which this case was prosecuted.

There was little question in these righteous minds that the boy should be dispatched to the flames for his egregious violations of natural law, but there was confusion on the bench over which sheep, exactly, he’d been defiling, and therefore which of them should be killed and which of them spared. This was crucial to sort out, not only because livestock was a valuable commodity in the beleaguered settlement, but also because if they executed the wrong sheep, they risked the unthinkable happening: a monstrously bleating, hoofed prodigy might drop undetected onto Plymouth. So, naturally, a lineup of busily masticating victims was staged for Granger. With a trembling finger, the boy pointed out those five amber-eyed ruminants that had been targets of his secret woolly lust. Court records indicate that the animals were then “killed before his face, according to the law, Leviticus xx. 15; and then he himself was executed.”

Suspected “buggers” of the past—Old English slang for he who has sex with pigs, donkeys, dogs, and all and sundry critters—could expect a battle of wits with moral arbiters and overzealous prosecutors. In New Haven in 1642, not far from what would later be the Yale campus and just a few years after the Granger affair, a man named George Spencer, a servant notorious for having “a prophane, lying, scoffing and lewd speritt,” was executed for making love to his master’s pig. He swore that he didn’t do it, but unfortunately for Spencer the sow happened to give birth to a deformed fetus (“a prodigious monster”) that resembled George a bit too closely for most people’s comfort. The pig fetus had “butt one eye for use, the other hath (as it is called) a pearle in itt, is whitish and deformed.” This embryological mishap was George’s death sentence. His own ocular deformity bore an uncanny resemblance to that of the stillborn pig, and in the emotional climate of the town’s moral panic over grunting prodigies, this was the critical piece of evidence used to convict him.

Another town resident with the rather ironic name of Thomas Hogg also found himself at the center of an intense buggery investigation when a neighborhood sow bore a deformed fetus with “a faire & white skinne & head, as Thomas Hogg is.” (I feel compelled to pause for a moment to pity the women of old New Haven, too, since so many aborted pig fetuses were apparently reminiscent of the town’s eligible bachelors.) The allegations made against Thomas Hogg by the townsfolk were so serious that the governor and the deputy governor personally frog-marched him out to the barnyard toward the sow in question and ordered him to “scratt” (fondle) the animal before their eyes. This was done to gauge just how intimately familiar they might be. “Immedyatly there appeared a working of lust in the sow,” the court records recount, “insomuch that she powred out seede before them.” When Hogg reluctantly titillated the teats of a different sow, by contrast, she didn’t return his affections. At least, she didn’t release her bladder when he touched her teats, which is probably what that earlier pig had done. Given his accusers’ unimpressive knowledge of biology, she seems simply to have peed at the worst of times. So Hogg, like Granger and Spencer before him, was executed.

These zero-tolerance laws against bestiality had been imported from Christian Europe, the stomping ground of zealots like Aquinas. But an interesting development emerged on that side of the Atlantic in the eighteenth century, highlighted by the case of a ragged French peasant named Jacques Ferron, who was tried for having sex with a female donkey. As described by Edward Payson Evans in his 1906 cult classic of legal scholarship, The Criminal Prosecution and Capital Punishment of Animals, Ferron would clearly be killed, since he was “taken in the act of coition” with the animal. He’d soon be shoved along in shackles to the public square, where a smoldering stake was waiting to consume him in flames as he pleaded for mercy against a wall of scornful faces. What makes Ferron’s case different from the bestiality trials up to then is that the locals chose not to slay the jenny along with him. In fact, the donkey was so beloved by the community that she was instead given her own separate trial, with witnesses to testify that not once had they ever seen her exhibit even the slightest sign of promiscuity. Before the proceedings, a certificate was even drawn up affirming the donkey’s virtuous reputation. This impassioned plea was signed by the parish priest and was enough to persuade the court officials to acquit the animal on the grounds that she’d quite clearly been raped.

This French donkey-rape case may sound somewhat absurd to us today. But it was a small moment in history in which people stopped and questioned the punishment demanded by the Bible and instead chose their own more rational course of action, showing how even a society steeped in religion can move away from the irrelevant question of naturalness and onto the more meaningful and moral one of harmfulness in its consideration of sexual deviance. Personally, I don’t think Ferron got a fair shake, since harm to the animal hadn’t really been established. Most of us (me included) don’t especially enjoy the thought of a man screwing a donkey, let alone such an apparently virtuous one, but anyone who has ever seen the erect penis of an adult jackass, approximately the size of a small moped, would have to acknowledge that it’s unlikely Ferron’s member caused physical injury to the donkey. And unless she stopped eating, was ostracized by the group, or felt ashamed by the judgmental glares of the other donkeys, psychological damage was also unlikely. Still, since God clearly prescribes death to any creature, willing or unwilling, tainted by human semen, the sparing of this she-ass meant her perceived harm (by rape) was important enough to these people to ignore God’s unreasonable and cruel orders to kill her. They thought for themselves in this sexual ethical dilemma, in other words. And that’s real moral progress. (True, they still chose to burn the human being alive. But—baby steps.)

Since we now know that many people of European descent possess Neanderthal DNA, it’s tempting to speculate about how many of those stoking the fires of yore were flesh-and-blood prodigies themselves. My Heinz 57 genome has never been sequenced, but there’s a good chance I’m a hybrid in this sense, too. (See, my adolescent caveman crush was perfectly “natural.”) But in any event, once some basic biological knowledge put an end to the paranoia over Aquinas’s evil prodigies not long after the Ferron affair, Christians abandoned the practice of immolating those accused of interspecies sex.

It’s foolish, however, to assume that religious morality isn’t still woven into modern bestiality laws (even the term “bestiality” is religious, first appearing in the King James Version of the Bible in 1611 to falsely cleave apart human beings from all other animals). We’re a peculiar species, but humans are animals too, of course. Bestiality is expressly illegal in most countries today, and in those places where it’s not an officially codified crime, people who have sex with animals are still occasionally prosecuted under animal cruelty laws. As a platonic animal lover, I’m in favor of protective laws. The sad reality is that there are indeed hideous sexual deeds done to animals by a few demented people. Yet there are also cases of human-animal sex that don’t involve any obvious harm to the animal and may even involve mutual pleasure. Which is worse, for instance, a stud manager forcibly collecting the semen of a prized racehorse by “electro-ejaculating” the animal for commercial gain (which involves inserting an electrified rod into the animal’s rectum and delivering a high-voltage shock to its prostate) or a zoophile gently masturbating his companion horse with the sole intent of bringing it satisfaction? That the first is perfectly legal and the second illegal shows that bestiality laws are more concerned with a person’s sexually deviant desires than they are with the animal’s actual harm. When the question of harm is an afterthought in any sex law, we need to rethink both its fairness and how it’s handled by the courts. There is the problem of an animal’s inability to give verbal consent. But note that many zoophiles prefer to be the passive recipients of the animal’s actions upon—or more often inside—them. That’s still completely illegal, even in cases of volitional thrusting (think humping dog to human leg), which seems to imply the animal is more or less on the same page with the zoophile. Funny enough, that equally thorny problem of how to gain an animal’s verbal consent before it’s killed for one’s personal dining pleasure doesn’t inspire nearly the same degree of outrage. Not that either is great, but if I were a bovine, I’d rather get “humanely” penetrated by the penile equivalent of a stiff strand of hay than be “humanely” slaughtered by seventeen-inch steel blades. (I think I might have to draw a firm line with all this at juvenile goats, though. They’re just kids, for God’s sake.)

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Most modern sex crime laws are based on the better-safe-than-sorry principle. And that’s quite sensible. We especially want to protect the most vulnerable members of our society—children, animals, the elderly, the disabled—so we err on the side of extreme caution, even if this means occasionally getting it wrong about the actual harm that they face. After all, what’s the life of one well-meaning, gentle sex deviant when it comes to protecting those we care about? Lumping that unfortunate sap in with the nastier variety is a chance you’re probably willing to take. Once you accept that we’re all sex deviants in our own ways, however, the life of that expendable pervert is more than just collateral damage. That unfortunate sap could, in fact, be you someday, or the very child you’re trying to protect. Given the serious consequences of our “true natures” being known, is it any wonder that your first thought (and I’m paraphrasing here) was “Speak for yourself” when I initially called you a pervert?

It’s far easier to assume that all sex deviants, including even some of those who’ve committed crimes, are immoral than it is to show, case by case, how they’ve caused measurable harm. “In all the criminal law,” Alfred Kinsey once pointed out, “there is practically no other behavior which is forbidden on the ground that nature may be offended, and that nature must be protected from such offense. This is the unique aspect of our sex codes.” Once the Bible and the legal system aren’t there to tell us how to think about sex (neither of which, you may have gathered, I’ll be using as a source of moral authority for our consideration in the chapters ahead), establishing harm can require strenuous mental effort. In fact, you might think you’re pretty good at knowing sexual right from wrong. But even our most fervent intuitions aren’t always as logical as we’d like to believe.

Back in 2001, the psychologist Jonathan Haidt coined the term “moral dumbfounding” to refer to the phenomenon in which we struggle to elaborate on the precise reasons why we believe certain acts are immoral. Emotionally fueled tautologies (or expressions of redundancy that fail to offer any actual clarification, such as “It’s wrong because it’s just nasty,” “You shouldn’t do it, because it’s creepy,” “It’s immoral because it’s plain evil,” and of course “It’s not right, because God says so”) only echo intense social disapproval for certain crimes that shouldn’t be crimes at all when we prioritize the question of harmfulness. Consider a vignette from a study in this area:

A man belongs to a necrophilia club that has devised a way to satisfy the desire to have sex with dead people. Each member donates his or her body to the club after death so that the other members can have sex with the corpse. The man has sex with a dead woman who gave her body to the club.

When asked whether it was wrong for this man to do what he did and, more important, to articulate and to justify their belief if they said it was, most participants in this study defaulted to a presumption of harm in their moral reasoning. Even when they were told explicitly that the woman didn’t have any family members who might get upset if they found out what happened to her corpse, that the club isn’t interested in recruiting or harming living people, that neither the man nor any of the other club members suffer any regrets or anguish about their sexuality, that the group’s activities are kept private and consensual, that the man used protection to prevent disease, and, per her instructions, that the club cremated the woman’s body after the man was done having sex with it, people still insisted that somehow or another, someone, somewhere, must be getting harmed.

For social conservatives, the damage might even be seen as inflicted on symbolic bodies—“America,” for example, “the Church,” “society,” or “the sanctity of marriage.” Saying that a behavior is “harmful to America” or that it’s “destructive to society” is a bit like giving corporations the legal status of personhood. That is, it only makes sense to those with an agenda. The scientific definition of a “person” as a carbon-based life-form resembles nothing of the circuitous legal definition that enables a profit-driven corporation to claim that same status. Likewise, pain and distress can occur only at the level of a subjectively experiencing organism (human or animal) in possession of pain receptors and a nervous system able to register emotional trauma, not at the level of an abstract entity without a brain. The problem of sexual harm concerns living, breathing creatures, not political parties, nations, or worldviews.

The case of the responsible necrophile is just one example of deviant sex in which researchers have uncovered presumption-of-harm reasoning. When offered similarly clear information about eliminating all possible forms of measurable harm, participants trying to justify their feelings of the wrongfulness of sex with animals, teenagers, and family members (incest) likewise default to a presumption of harm. Such scenarios aren’t confined to artificial lab studies, either. They happen in the real world as well. Indeed, that’s the whole point: that not every “obvious” case is in fact so obvious.

Take the brothers Elijah and Milo Peters, for example, a pair of twentysomething identical male twins from Prague who appear together in gay porn films featuring full anal penetration—with each other. The Peters twins not only have been having sex together since they were fifteen but also consider themsel

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