Inside of a Dog: What Dogs See, Smell, and Know (28 page)

The first explanation is that dogs wear an actual clock—though internally. It is in the so-called
pacemaker
of their brain, which regulates the activities of other cells of the body through the day. For a few decades neuroscientists have known that circadian rhythms, the sleep and alertness cycles that we experience every day, are controlled by a part of the brain in the hypothalamus called the SCN (suprachiasmatic nucleus). Not only humans have an SCN: so do rats, pigeons, dogs—every animal, including insects, with a complex nervous system. These neurons and others in the hypothalamus work together to coordinate daily wakefulness, hunger, and sleep.* Deprived entirely of cycles of light and dark, we would all still go through circadian cycles; without the sun it takes just over twenty-four hours to complete a biological day.

This morning I heard her barking in her sleep—the muffled, jowl-puffing bark of dreaming. Oh, does she dream. I love her dream-barks, falsely severe, often accompanied by twitching feet or lips curled into a teeth-baring growl. Watch long enough and I'll see her eyes dancing, the periodic clenches of her jaw, hear her tiny whimpers. The best dreams inspire tail-wags—huge thumps of delight that wake herself and me.

We humans experience the day according to our ideas about what typically or ideally will happen throughout it—what meals, work, play, conversation, sex, commuting, naps—and also according to the cycle of our circadian rhythms. Given our attention to the former, though, we sometimes hardly notice that our bodies are charting a regular course through the day. That midafternoon sleepiness, the difficulty in rising at five in the morning—both are due to our activities clashing with our circadian rhythms. Take away some of those human expectations and you've got the dog's experience: the bodily feelings of the passage of the day. In fact, without the societal expectations to distract them, they may be more attuned to the rhythms of their body telling them when to rise and when to eat. As per their pacemaker, they are most active as dark gives way to dawn, and markedly reduce their activity in the afternoon, with a burst of energy in the evening. With nothing else to do—no papers to shuffle, no meetings to attend—dogs nap straight through that afternoon slowdown.

Even without regular mealtimes the body goes through feeding-related cycles. Right before it is time to eat, animals tend to be more active—running about, licking, salivating—in anticipation of food. We see this food-sense when a dog pursues us relentlessly with panting mouth and appealing eyes. Eventually we figure out it is time to feed the dog.

So in fact one can set the clock by the dog's belly. And, even more impressive, dogs maintain a clock operated by other mechanisms not yet fully understood, which seem to read the day's air. Our local environment—the air in the room we are in—indicates (if we have the right indicator) where we are in the day. Although we do not typically sense it, it is just the sort of thing a dog might notice. If we attend carefully, we might notice the gross changes of the day: the cool at the moment the sun sets, or the time of day registered in the amount of light streaming in the window—but the day's changes are infinitely more subtle than this. With sensitive machinery, researchers can detect the gentle air currents that form as a summer's day ends: warmed air pulled up along the inner walls creeps across the ceiling, spilling into the center of the room and falling along the outer walls. This is no breeze, nor even a noticeable puff or waft. Yet the sensitive machinery that is the dog evidently detects this slow, inevitable flow of air, perhaps with the help of their whiskers, well positioned to register the direction of any scent on the air. We know they can detect it because they can also be fooled: brought into a room that was warmed, a dog trained to follow a scent trail may search first by the windows when the track is really closer to the room's interior.

She is patient. How she waits for me. She waits as I duck into the local grocery store: looking plaintively, then settling down. She waits at home, warming the bed, the chair, the spot by the door, for me to return. She waits for me to finish up what I'm doing before we go outside; for me to finish talking with someone during our walk; for me to figure out when she is hungry. She waited for me to finally realize where she liked to be rubbed. And for me to finally begin to figure her out. Thanks for waiting, kiddo.

Dogs have not been tested on their ability to detect a specific length of time; but bumblebees have. In one study, bees were trained to wait for a fixed time interval before sticking a proboscis through a tiny hole for a bit of sugar. Whatever the interval, they learned to restrain themselves for just that long … and then no longer. When you're a bee waiting for sugar water, a half minute is a long time to wait. But they patiently tapped their many feet and did so. Other well-experimented-on animals—rats and pigeons—do the same: measuring time.

It is probable that your dog knows just how long a day is. But if so, a horrible thought occurs: Mustn't dogs be terribly bored enduring that day all alone at home? How can we tell if a dog is bored? Like other concepts whose applicability to dogs we are curious about, we first need to get a handle on what boredom looks like. Any child will tell you when he is bored, but dogs don't—at least, not verbally.

Boredom is rarely discussed in the non-human scientific literature, because it is one of the classes of words whose application to animals is thought suspect. "Man is the only animal who can be bored," the social psychologist Erich Fromm declared; dogs should be so lucky. Human boredom is rarely the subject of scientific scrutiny, either, perhaps because it is seen simply as a part of the experience of life, not as a pathology to scrutinize. Its very familiarity gives us a way to define it: we experience it as a profound ennui, as an utter lack of interest. And we can recognize it in others: in their flagging energy, in an uptick in repetitive movements and a decline in all other activities, and in rapidly waning attention.

With this definition, the subjective becomes objectively identifiable, in dogs as well as humans. Flagging energy and reduced activity are simple to recognize: less moving and more lying and sitting. Attention may wane straight into protracted bouts of sleep. Repetitive movements include stereotyped (aimlessly and endlessly repeated) or self-directed behaviors. We twiddle our thumbs when bored; we pace. Animals kept in barren zoo enclosures often pace madly—and, thumbless, have twiddle-equivalents: licking or chewing skin or fur obsessively and constantly, pulling out their own feathers, rubbing their ears or face, rocking back and forth.

So is your dog bored? If you return home to find apparently restless socks, shoes, or underwear that have magically migrated some small distance from where you left them, or straggled bite-sized reminders of what you threw in the garbage yesterday—the answer is both
Yes,
your dog was bored, and
No,
at least not during one manic hour of chewing. Imagine a child complaining,
There's nothing to do:
that is just the case for most dogs left alone. Left without anything to do, they will find something. Your solution, for the sake of your dog's mental health, and for the sake of your socks, is as simple as leaving something for them to do.

Even if you return to find the house a bit unkempt, a warm depression on the forbidden couch cushion, what is also reliable is that the dog is still alive and usually looks well. We get away with leaving them, with boring them, because they generally adapt to their situations without much complaint. In fact, dogs take comfort in habit, in reliable occurrences, just as we might. If so, then their boredom may be tempered by resignation to the familiar. And they may even know how long they typically need to stay in the suspended animation of waiting at home for you. It is one reason why your dog may be waggily waiting at the door even when you try to quietly sneak in at the workday's end. And it is why I leave more treats hidden around the apartment the longer I will be gone. I'm telling Pump I'll be away—and leaving something to mind the time.

The best scientific tool proposed to determine if dogs think about themselves—if they have a sense of self—is a simple one: the mirror. One day the primatologist Gordon Gallup pondered his reflection while shaving and wondered if the chimpanzees he studied would ponder their reflections in mirrors, too. Certainly using a mirror for self-examination—smoothing a shirt over belly, patting down a wayward hair, testing a coy smile—is a display of our own self-awareness. And before we are self-aware, as young children, we do not use mirrors as adults do. A short time before children pass theory-of-mind tests, they begin to consider their mirror images.

Gallup promptly placed a full-length mirror outside his chimpanzees' cages and watched what they did. They all did the same thing first: they threatened and tried to attack the mirror. Suddenly, it seemed, there was another chimp right outside their cage; this must be addressed at once. Despite the no doubt confusing result—the mirror image seemed to attack back, only for the affair to resolve without ado—their first days with the mirrors were full with social displays toward this new, glaring chimpanzee. After a few days, though, the chimpanzees seemed to come to a realization. Gallup watched as his chimps approached the mirrors and began to use them to examine their own visages and bodies: picking at their teeth, blowing bubbles, making faces toward their mirror image. They were especially interested in parts of their bodies that are ordinarily visually inaccessible: the mouth, the rump, up the nostrils. To be sure that they were thinking about the mirror images as
themselves,
Gallup devised a "mark" test: he inconspicuously applied a prominent dab of red ink to the head of the chimps. These first subjects in this test needed to be anesthetized to apply the mark; later researchers would affix the mark while doing ordinary grooming or medical care of their animals. When the marked chimps again stood in front of the mirrors, they saw a red-tagged chimp—and they touched the spot on their own heads, bringing their hands down to examine the ink with their mouths. They passed the test.

There is considerable debate about whether this indicates that chimpanzees are thinking about themselves, have a concept of self, recognize themselves, are self-aware, or none of the above*

—especially since it would be disruptive of our ideas about animals to suddenly grant them self-awareness. But the mirror tests have continued alongside the debate, and to this date dolphins (by moving their bodies to explore the mark) and at least one elephant (using her trunk) have passed the test; monkeys have not. And dogs? Dogs have not been shown to pass the test. They never examine themselves in the mirror. Instead they behave more like monkeys do: they sometimes look at the mirrors as though it were another animal, and sometimes look at it idly. In some cases, dogs will use mirrors to get information about the world: to see you tiptoeing up behind them, for instance. But they don't seem to see the mirror as an image of themselves.

There are a few explanations why dogs might behave this way. The dogs may indeed not have any sense of self—thus no sense of who that handsome dog in the mirror might be. But as the debate over this test indicates, it is not universally accepted as a conclusive test of self-awareness; thus neither can it be a conclusive determination of lack of self-awareness. Another possible explanation for the dogs' behavior is that the lack of other cues—specifically olfactory cues—coming from the mirror image leads dogs to lose interest in investigating it. Some fantastical odor-mirror that wafts the dog's own scent while reflecting the dog's own image would be a better medium for this test. Another issue is that the test is predicated on a specific kind of curiosity about oneself: one that leads humans to examine what is new on our own bodies. Dogs may be less interested in what is visually new than what is tactually new: they notice strange sensations and pursue them with nibbling mouth or scratching paw. A dog is not curious why the tip of his black tail is white, or what the color of his new leash is. The mark needs to be noticeable, and also worth noting.