A Natural History of the Senses (6 page)

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 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 stalwart 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.”

One of Gilbert’s colleagues, George Preti, staged an experiment in which ten women had the sweat of other women applied under
their noses at regular intervals. It took three months for the women to begin menstruating at the same time as the women whose sweat they were smelling. A control group, daubed with alcohol instead of sweat, didn’t change their cycles at all. Clearly, a pheromone in sweat affects menstrual synchrony, which is why women in dorms or close girlfriends so often menstruate at the same time, a phenomenon known as the McClintock Effect (after Martha McClintock, the psychologist who first observed it). There appear to be other effects. When a man gets involved with a woman for any length of time, his facial hair starts to grow faster than it did before. Women who are cloistered away from men (in a boarding school, say), enter puberty later than women who are around men. Mothers recognize the odor of their newborn children, and vice versa, so some doctors are experimenting with
giving
children bursts of their mother’s odor, along with the anesthetic, during operations. Babies can smell their mother entering a room, even if they can’t see her. In J. M. Barrie’s
Peter Pan
, children can even “smell danger” while they sleep. Mothers of school-age children can pick out T-shirts worn by their own child. This is not true for fathers, who do not recognize the smell of their infants, but men can determine whether a T-shirt has been worn by a male or a female. Pheromones do affect people. But how much? Do pheromones trigger vigorous responses in us as they do in moths or beavers, or do they figure in the cascade of our sensory awareness no more significantly than ordinary visual or hearing cues? If I see a handsome man with beautiful blue eyes, am I having a “visualmone,” as one researcher called it dismissively, or is it just that blue eyes excite me because they register as attractive in the culture, time, and context of my life? Blue eyes, “baby blues,” remind us a little of Caucasian newborns, and fill us with protectiveness. But in some African cultures they would be thought ghoulish, icy, and unattractive.

Science fiction has often frightened us with humans as automatons, driven by unknown forces, their minds a sort of dial tone. Suppose pheromones at times secretly cancel our powers of choice and decision? The idea alarms. We don’t like to lose control, except
on purpose—during sex or partying or religious mysticism or doing drugs—and then only because we believe we’re just fractionally more in control than we’re not, or at least that such control will return to us quickly. Evolution is complex and at times amusing, so much of an adventure that few of its whims or obbligatos frighten me. Our apparent need for violence does, but not the possibility that we might be having elaborate, if subtle, conversations with one another through pheromones. Free will may not be entirely free, but it certainly is willful, and yet it seems as if there is a good deal of stretch in it. Such masterly ad-libbers as human beings know how to revise on almost any theme. If there’s one thing at which we really excel, it is at pushing limits, inventing strategies, finding ways to sidestep the rudest truths, grabbing life by the lapels and shaking it soundly. Granted, it tends to shake back, but that never stops us.

When we crawled or flopped out of the ocean onto the land and its trees, the sense of smell lost a little of its urgency. Later, we stood upright and began to look around, and to climb, and what a world we discovered spread out before us like a field of Texas bluebonnets! We could see for miles in all directions. Enemies became visible, food became visible, mates became visible, trails became visible. The shadow of a distant lion slinking through the grass was a more useful sign than any smell. Vision and hearing became more important for survival. Monkeys don’t smell things as well as dogs do. Most birds don’t have very sophisticated noses, although there are some exceptions—New World vultures locate carrion by smell, and seabirds often navigate by smell. But the animals with the keenest sense of smell tend to walk on all fours, their heads hanging close to the ground, where the damp, heavy, fragrant molecules of odor lie. This includes snakes and insects, too, along with elephants (whose trunks hang low), and most quadrupeds. Pigs can smell truffles under six inches of soil. Squirrels find nuts they buried months earlier. Bloodhounds can smell a man’s scent in a room he left hours before, and
then track the few molecules that seep through the soles of his shoes and land on the ground when he walks, over uneven terrain, even on stormy nights. Fish need olfactory abilities: Salmon can smell the distant waters of their birth, toward which they must swim to spawn. A male butterfly can home in on the scent of a female that is miles away. Pity us, the long, tall, upright ones, whose sense of smell has weakened over time. When we are told that a human has five million olfactory cells, it seems like a lot. But a sheepdog, which has 220 million, can smell forty-four times better than we can. What does it smell? What are we missing? Just imagine the stereophonic world of aromas we must pass through, like sleepwalkers without headphones. Still, we do have a remarkably detailed sense of smell, given how small our organs of smell really are. Because our noses jut out from our faces, odors have quite a distance to travel inside them before we’re aware of what the nose has probed. That’s why we wrinkle up our noses and sniff—to move the molecules of smell closer to the olfactory receptors hidden awkwardly in the backmost recesses of the nose.

Few pleasures are as robust as the simple country pleasure of sneezing. The whole body ripples in orgasmic delight. But only humans sneeze with their mouths open. Dogs, cats, horses, and most other animals just sneeze straight down their noses, with the air bending a little at the neck. But humans huff and tremble in an anticipatory itch, draw in a big gobful of air, contract the ribs and stomach like a bellows, and violently shoot air into the nose, where it stops short, blasts the general area, and sometimes sprays messily out of the nose and mouth all at once. This wouldn’t matter too much if our lungs blew air out gently during a sneeze. But researchers at the University of Rochester have found that a sneeze expels the air at eighty-five percent the speed of sound, fast enough to scour bacteria and other detritus from the body, the sneeze’s goal. Human noses have a hairpin turn way at the back of the nasal passages, which makes the
whole process of breathing more taxing, and inhaling odor molecules more difficult. There is no direct path for the air to follow in a sneeze. We have to open our mouths. If we sneeze closed-mouthed, the air thunders around the cavities and passages in our heads, looking for a way out, and can hurt our ears. There are many theories about why our noses are so poorly designed; in the last analysis, it probably has to do with the evolution of our biggish brains and the cramped space in our skulls, and to permit stereo vision. Bedichek suggests that the design didn’t become awkward until we “swarmed into those congested areas we call ‘cities.’ Here the nose has had forced upon it suddenly a function it was never intended to perform, namely, screening out dust and grit while at the same time being subjected to intolerable odors of municipal filth, and finally to fumes from the vast chemical laboratory the modern city has become.” The seventeenth-century poet Abraham Cowley states the point as a rhetorical question: