A Natural History of the Senses

by Diane Ackerman

  THE OCEANS INSIDE US

  Driving through farm country at summer sunset provides a cavalcade of smells: manure, cut grass, honeysuckle, spearmint, wheat chaff, scallions, chicory, tar from the macadam road. Stumbling on new smells is one of the delights of travel. Early in our evolution we didn’t travel for pleasure, only for food, and smell was essential. Many forms of sea life must sit and wait for food to brush up against them or stray within their tentacled grasp. But, guided by smell, we became nomads who could go out and search for food, hunt it, even choose what we had a hankering for. In our early, fishier version of humankind, we also used smell to find a mate or detect the arrival of a barracuda. And it was an invaluable tester, allowing us to prevent something poisonous from entering our mouths and the delicate, closed system of our bodies. Smell was the first of our senses, and it was so successful that in time the small lump of olfactory tissue atop the nerve cord grew into a brain. Our cerebral hemispheres were originally buds from the olfactory stalks. We think because we smelled.

  Our sense of smell, like so many of our other body functions, is a throwback to that time, early in evolution, when we thrived in the oceans. An odor must first dissolve into a watery solution our mucous membranes can absorb before we can smell it. Scuba-diving in the Bahamas some years ago, I became aware of two things for the first time: that we carry the ocean within us; that our veins mirror the tides. As a human woman, with ovaries where eggs lie like roe, entering the smooth, undulating womb of the ocean from which our ancestors evolved millennia ago, I was so moved my eyes teared underwater, and I mixed my saltiness with the ocean’s. Distracted by such thoughts, I looked around to find my position vis-a-vis the boat, and couldn’t. But it didn’t matter: Home was everywhere.

  That moment of mysticism left my sinuses full, and made surfacing painful until I removed my mask, blew my nose in a strange two-stage snite, and settled down emotionally. But I’ve never forgotten that sense of belonging. Our blood is mainly salt water, we still require a saline solution (salt water) to wash our eyes or put in contact lenses, and through the ages women’s vaginas have been described as smelling “fishy.” In fact, Sandor Ferenczi, a disciple of Freud’s, went so far as to declare, in Thalassa: A Theory of Genitality, that men only make love to women because women’s wombs smell of herring brine, and men are trying to get back to the primordial ocean—surely one of the more remarkable theories on the subject. He didn’t offer an explanation for why women have intercourse with men. One researcher claims that this “fishiness” is due not to anything intrinsic to the vagina, but rather to poor hygiene after intercourse, or vaginitis, or stale sperm. “If you deposit semen in the vagina and leave it there, it comes out smelling fishy,” he argues. This has a certain etymological persuasiveness to it, if we remember that in many European languages the slang names for prostitutes are variations on the Indo-European root pu, to decay or rot. In French, putain; to the Irish, old put; in Italian putta; puta in both Spanish and Portuguese. Cognate words are putrid, pus, suppurate, and putorius (referring to the skunk family). Skunk derives from the Algonquin Indian word for polecat; and during the sixteenth and seventeenth centuries in England polecat was a derogatory term for prostitute. Not only do we owe our sense of smell and taste to the ocean, but we smell and taste of the ocean.

  NOTIONS AND NATIONS OF SWEAT

  In general, humans have a strong body odor, and anthropologist Dr. Louis S. B. Leakey thinks our ancestors may have had an even stronger odor, one that predatory animals found foul enough to avoid. Not long ago, I spent some time in Texas, studying bats. I placed a large Indonesian flying fox in my hair, to see if it would get entangled, as the old wives’ tales warned. Not only did it not tangle, it began to cough gently from the mingling smells of my soap, cologne, saltiness, oils, and other human odors. When I put it back in its cage, it cleaned itself like a cat for many minutes, clearly feeling soiled by the human contact. Many plants—like rosemary or sage—have evolved pungent odors to repel predators; why not animals? Nature rarely wastes a winning strategy. Of course, some humans have much stronger odors than others. Folk wisdom says that brunettes “smell different” from redheads, who smell different from blondes. There’s been so much anecdotal evidence about different races having distinctive odors—because of diets, habits, hairiness or lack of it—that such claims are difficult to discount, even though the topic scares most scientists, who are understandably concerned about being called racist.* There hasn’t been a great deal of research into national and racial odors. In any case, one culture doesn’t “smell” better or worse than another, just different, but that may be why the word “stinking” so often appears as an adjective in streams of racial abuse. Asiatics don’t have as many apocrine glands at the base of hair follicles as occidentals do, and as a result they often find Europeans ripe-smelling. A strong body odor among Japanese men is so rare that at one time it could disqualify them from military service. This is also why there is so much scenting of the room and air in Asian life, and much less scenting of the body. Pungent odors are absorbed by fats: If you put an onion or cantaloupe in the refrigerator with an open tub of butter, the butter will absorb the odor. Hair also contains fat, which is why it leaves grease stains on pillows and antimacassars. It absorbs smells, too, like smoke or cologne. The hairiness of Caucasians and Blacks makes them very sweaty compared to Asians, but colognes simmer in their oil and warmth like votive candles.

  Body odor comes from the apocrine glands, which are small when we’re born and develop substantially during puberty; there are many of them scattered around our armpits, face, chest, genitals, and anus. Some researchers conclude that a large part of our joy in kissing is really a joy in smelling and caressing each other’s face, where one’s personal scent glows. Among far-flung tribes in a number of countries—Borneo, on the Gambia River in West Africa, in Burma, in Siberia, in India—the word for “kiss” means “smell”; a kiss is really a prolonged smelling of one’s beloved, relative, or friend. Members of a tribe in New Guinea say good-bye by putting a hand in each other’s armpit, withdrawing it and stroking it over themselves, thus becoming coated with the friend’s scent; other cultures sniff each other or rub noses in greeting.

  THE PERSONALITY OF SMELL

  Meat eaters smell different from vegetarians, children smell different from adults, smokers smell different from nonsmokers; other individuals smell different because of hereditary factors, health, occupation, diet, medication, emotional state, even mood. As Roy Bedichek observes in The Sense of Smell: “The body odor of his prey excites the predator so that his mouth waters and every fiber of his being becomes taut and every sense alerted. At the same time in the nostrils of the prey, fear and hate become associated with the body odor of the predator.* Thus on low levels of animal life, a specific odor evolves along with and becomes identified with a specific mood.” Each person has an odor as individual as a fingerprint. A dog can identify it easily and recognize its owner even if he or she is one of a pair of identical twins. Helen Keller swore that by simply smelling people she could decipher “the work they are engaged in. The odors of the wood, iron, paint, and drugs cling to the garments of those who work in them.… When a person passes quickly from one place to another, I get a scent impression of where he has been—the kitchen, the garden, or the sickroom.”

  For those of exquisite sensuality, there is nothing headier than the musky smell of a loved one moist with sweat. But natural body odors don’t strike most of us as particularly enticing. In the Elizabethan Age, lovers exchanged “love apples”—a woman would keep a peeled apple in her armpit until it was saturated with her sweat, and then give it to her sweetheart to inhale. Now we have whole industries devoted to removing our natural odors and replacing them with artificial ones. Why do we prefer our breath to smell of peppermint instead of rotting bacteria, our “natural” smell? True, a foul smell might signal disease: We might not be attracted to someone giving off an unhealthy odor, and an excess of rotting b
acteria could persuade us we are chatting with, say, a cholera victim, someone who could infect us. But mainly we value one scent over another thanks to Madison Avenue’s brashness and our gullibility. Aromatic paranoia pays well. In creative greed, they’ve frightened us into thinking that we’re “offensive” and require lotions and potions to mask our natural odors.

  Just what do we mean by a bad smell? And what is the worst smell in the world? The answers depend on culture, age, and personal taste. Westerners find fecal smells repulsive, but the Masai like to dress their hair with cow dung, which gives it an orangey-brown glow and a powerful odor. Children like most smells until they’re old enough to be taught differently. When naturalist and zookeeper Gerald Durrell wanted to catch some fruit bats for his zoo on the Isle of Jersey, he went to the island of Rodriguez, east of Madagascar, and baited his net with what he called “jackfruit,” a big, brown durianlike hedgehog of a fruit, whose white pulp reeked “like a cross between an open grave and a sewer,” a regular “charnel house.” That sounds pretty bad to me, and so, just to see if he’s right, I’ve put “Rodriguez in jackfruit season” on the long list of sensory destinations I’d like to get to one day.

  Though ancient and uncontrollably natural, a fart is generally considered to be repellant, discourteous, and even the smell of the devil. The Merck Manual, in an uncharacteristically entertaining chapter on “Functional Bowel Disease,” subheading “Gas,” describes the possible origins, treatments of, and miscellaneous symptoms and signs of gas, along with this observation:

  Among those who are flatulent, the quantity and frequency of gas passage can reach astounding proportions. One careful study noted a patient with daily flatus frequency as high as 141, including 70 passages in one 4-h period. This symptom, which can cause great psychosocial distress, has been unofficially and humorously described according to its salient characteristics: (1) the “slider” (crowded elevator type), which is released slowly and noiselessly, sometimes with devastating effect; (2) the open sphincter, or “pooh” type, which is said to be of higher temperature and more aromatic; and (3) the staccato or drum-beat type, pleasantly passed in privacy.

  While questions of air pollution and degradation of air quality have been raised, no adequate studies have been performed. However, no hazard is likely to those working near open flames, and youngsters have even been known to make a game of expelling gas over a match-flame Rarely, this usually distressing symptom has been turned to advantage, as with a Frenchman referred to as “Le Pétomane,” who became affluent as an effluent performer on the Moulin Rouge stage.

  In his fascinating history of stench, perfume, and society in France, The Foul and the Fragrant, Alain Corbin describes the open sewers of Paris at the time of the revolution, and points out how strong a role scent has also played in fumigation throughout history. There are various forms of fumigation—fumigation for health reasons (especially during plagues); insect fumigation; and even religious and moral fumigation. The floors of medieval castles were strewn with rushes, lavender, and thyme, which were thought to prevent typhus. Perfumes were often used for magical and alchemical purposes, too, promising an enchantment. If the promises of today’s perfume ads seem extravagant, consider those made in the sixteenth century. In Les secrets de Maistre Alexys le Piedmontois, a book on cosmetics, the author promises that his toilet water will make women not just attractive for an evening but beautiful “forever.” “Forever” is pretty serious advertising, and probably should tip off a potential consumer to read the fine print. Here is the ghoulish recipe: “Take a young raven from its nest, feed it on hard-boiled eggs for forty days, kill it, then distill it with myrtle leaves, talcum powder, and almond oil.” Splendid. Except for the stench, and an overwhelming desire to quote Poe, you’ll surely be a ravenous beauty perching on the eaves of forever.

  PHEROMONES

  Pheromones are the pack animals of desire (from Greek, pherein, to carry, and horman, excite). Animals, like us, not only have distinctive odors, they also have powerfully effective pheromones, which trigger other animals into ovulation and courtship, or establish hierarchies of influence and power. They scent-mark, sometimes in ingenious ways. Voles and bush babies spray the soles of their feet with urine and brand the earth with it as they patrol their territories. Antelopes mark trees using scent glands on their faces. Cats have scent glands on their cheeks, and can often be seen “cheeking” someone or a favorite table leg. When you pet a cat, she will, if she likes you, lick herself to taste your scent. And then she’ll probably choose your favorite armchair to claw and curl up in, not just because of its cushions but because your scent is on it. The polecat, as well as the badger, drags its anus along the ground to mark it. Jane Goodall, in The Innocent Killers, reports that male and female wild dogs scent-mark one after the other on exactly the same blades of grass, to inform all interested parties that they are a pair. When my friend takes her German shepherd Jackie out for a walk, Jackie sniffs at curb, rock, and tree, and soon senses what dog has been there, its age, sex, mood, health, when it last passed by. For Jackie, it’s like reading the gossip column of the morning newspaper. The lane reveals its invisible trails to her nose as it doesn’t to her owner. She will add her scent to the quilt of scents on a tuft of grass, and the next dog that comes along will read, in the aromatic hieroglyphics of the neighborhood, Jackie, 5:00 PM, young female, on hormone therapy because of a bladder ailment, well fed, cheerful, seeks a friend.

  Sometimes messages can’t be merely immediate; they need to last over time, and yet be a constant signal, like a lighthouse guiding animals through the breakwaters of their uncertainty. Most smells will glow for a while, where a wink may vanish before it’s seen, a flexed muscle imply too many things, a voice startle or threaten. For an animal who is prey, the odor of its hunter will warn it; for the hunter, the odor of its prey will lure it. Of course, some animals exude an odor as a form of defense. Spotted skunks do a handstand and squirt would-be attackers with a horrible stench. Among insects, odor is all forms of communication: a guidebook to nesting or egg-laying spots, a rallying cry, a trumpet flourish announcing royalty, an alarm warning of ambush, a map home. In the rain forest, one can see long, ropy caravans of ants, marching single file along trails of scent that have been laid down for them by scouts. They may seem to be scrambling around in a blind fury of industriousness, but they are always in touch with one another, always gabbing about something meaningful to their lives. A male butterfly of the Danaidae family travels from flower to flower, mixing a cocktail of scents in a pocket on each hind leg until he has the perfect perfume to attract a female.* Birds sing to announce their presence in the world, mark their territories, impress a mate, boast of their status—ultimately, much of it has to do with sex and mating. Mammals prefer to use odors when they can, spinning scent songs as complex and unique as bird songs, which also travel on the air. Baby kangaroos, puppies, and many other mammals are born blind and must find their way to the nipple by smell. A mother fur seal will go out fishing, return to a beach swarming with pups, and recognize her own partly by smell. A mother bat, entering a nursery cave where millions of mother and baby bats cling to the wall or wing through the air, can find her young by calling to it and smelling a path toward it. When I was on a cattle ranch in New Mexico, I often saw a calf with the skin of another calf tied around its back, nursing happily. A cow recognizes her calf by smell, which triggers her mothering instincts, so whenever there was a stillborn, the rancher would skin the dead calf and give its scent to an orphan.

  Animals would not be able to live long without pheromones because they couldn’t mark their territories or choose receptive, fertile mates. But are there human pheromones? And can they be bottled? Some trendy women in Manhattan are wearing a perfume called Pheromone, priced at three hundred dollars an ounce. Expensive perhaps, but what price aphrodisia? Based on findings about the sexual attractants animals give off, the perfume promises, by implication, to make a woman smell provocative and turn st
alwart men into slaves of desire: love zombies. The odd thing about the claims of this perfume is that its manufacturer has not specified which pheromones are in it. Human pheromones have not yet been identified by researchers, whereas, say, boar pheromones have. The vision of a generation of young women walking the streets wearing boar pheromones is strange, even for Manhattan. Let me propose a naughty recipe: Turn loose a herd of sows on Park Avenue. Mix well with crowds of women wearing Pheromone eau de cologne. Dial 911 for emergency.

  If we haven’t yet pinpointed human pheromones, surely we can just use our secretions the way animals do, bottle our effluvia at different times of the month. Avery Gilbert, a biophysiologist, doesn’t think so. It’s more like psychology in a vial. He told Gentleman’s Quarterly that “If you had a bottle full of fluids generated by the female genital glands during copulation, and you put it on a guy’s desk, and if he even recognized the odor, he’d be embarrassed. Because it’s out of context, and that’s what makes the difference. If male consumers actually believe a claim that this component will get women hot, then they’re naïve. I don’t think there is a chemical that will do that. But it may not be important what particular odor men are broadcasting; it’s the signal of availability, the perception of self-confidence. Those claims are implied and probably work. And that’s probably the basic reason people wear the stuff.”