Inside of a Dog: What Dogs See, Smell, and Know (23 page)

Science has confirmed the importance of behavior in identity. Our identities, who we are, are defined partly by our actions, so we can examine how actions inform recognition of personal identity. In one experiment, dogs showed that they have no difficulty distinguishing friendly and unfriendly strangers: those demonstrating different identities. To do this, the experimenters divided participants into two groups and asked members of each group to behave in a prescribed manner. Friendly behavior included walking at a normal speed, talking to the dog in a cheerful voice, and gently petting the dog. Unfriendly behavior included actions that could be interpreted as threatening: an erratic, hesitating approach combined with staring at the eyes of the dog without talking.

The main result of the experiment is not all that surprising: the dogs approached the friendly and avoided the unfriendly. But there's a hidden gem in the experiment. The key trial was this: How did the dogs act when a formerly friendly person suddenly acted threatening? The dogs acted variably: For some, the person was now a different kind of person altogether—an unfriendly one, her identity changed. To others, the olfactory recognition of the stranger who had been friendly trumped this new odd behavior.

These people began as strangers to the dog, but over the course of the sessions, dogs became familiar with the various people: they became "less strange." Their identity was defined in part by their smell and in part by their behavior.

The combination of dogs' attention to us and their sensory prowess is explosive. We have seen their detection of our health, our truthfulness, even our relation to one another. And they know things about us at this very moment that we might not even be able to articulate.

The results of one study indicate that dogs pick up on our hormonal levels in interaction with them. Looking at owners and dogs participating in agility trials, the researchers found a correlation between two hormones: the men's testosterone levels, and the dogs' cortisol levels. Cortisol is a stress hormone—useful for mobilizing your response to, say, flee from that ravenous lion—but also produced in conditions that are more psychologically than mortally urgent. Increases in the level of the hormone testosterone accompany many potent elements of behavior: sex drive, aggression, dominance displays. The higher the men's pre-agility-competition hormonal levels, the higher the increase in the level of stress in the dogs (if the team lost). In a sense, the dogs somehow knew that their owner's hormonal level was high, by observing behavior or through scent or both—and they "caught" the emotion themselves. In another study, dogs' cortisol levels revealed that they were even sensitive to the
style
of play of human playmates. Those dogs playing with people who used commands during play—telling the dog to sit, lie down, or listen—wound up with higher postplay cortisol levels; those playing with people who played more freely and with enthusiasm had lower cortisol at play's end. Dogs know, and are infected by, our intent, even in play.

Being known and predicted by our dogs is no small part of our fondness for them. If you have experienced an infant's first smile at you as you approach, you know the thrill of being recognized. Dogs are anthropologists because they study and learn about us. They observe a meaningful part of our interaction with each other—our attention, our focus, our gaze; the result is not that they can read our minds but that they recognize us and anticipate us. It makes the infant human; it makes the dog vaguely human, too.

It's dawn and I try to sneak out of the room without waking Pump. I can't see her eyes, so dark they're camouflaged against her black fur. Her head rests peacefully between her legs. At the door I think I've made it—tiptoed and breath-held to avoid her radar. But then I see it: the swell of her lifted eyebrows tracking my path. She's on to me.

The dog, as we've seen, is a master looker, a skilled user of attention. Is there a thinking, plotting, reflective mind behind that look? The development of the human infant's looking into using attention marks the blossoming of the mature human mind. What does the dog's looking tell us about the dog mind? Do they think about other dogs, about themselves, about you? And the timeworn but still unanswered question of dog minds: Are they smart?

Dog owners, like new parents, always seem to have a handful of stories at the ready describing how smart their charges are. Dogs, it is claimed, know when their owners are going out, and when they are coming home; they know how to hoodwink us and they know how to beguile us. News reports buzz with the latest discovery of the intelligence of dogs: of their ability to use words, count, or call 911 in an emergency.

To verify this anecdotal impression, some have designed so-called
intelligence
tests
for dogs. We're all familiar with intelligence tests for humans: pen-and-paper creations that require you to solve SAT-like problems of word choice, spatial relationships, and reasoning. There are questions that test your memory, your vocabulary, your declining math skills, and your simple pattern-finding ability and attention to detail. Even putting aside whether the result is a fair assessment of intelligence, the design does not translate obviously to testing dogs. So revisions are made. Instead of tests of advanced vocabulary, there are tests of simple command recognition. Instead of repeating a list of digits read aloud, a dog may be asked to remember where a treat was hidden. Willingness to learn a new trick may replace the ability to figure complex sums. Questions loosely mimic experimental psychology paradigms: of object permanence (if a cup is placed over a treat, is it still there?), learning (does your dog realize what foolish trick you desire him to do?), and problem solving (how can he get his mouth on that food you've got?).

Formal studies of groups of dogs on these kinds of abilities—mostly cognition about physical objects and the environment—yield what at first seem to be unsurprising results. By bringing dogs to a field baited with treats and timing dogs' speed in finding them, researchers have confirmed that dogs use landmarks to navigate and find shortcuts. This behavior is consistent with what their wolflike ancestors would probably have done in finding food and finding their way. Dogs are, of course, pretty good at all tasks that involve getting themselves to food. Given a choice of two piles of food, dogs have no trouble choosing the larger one—especially as the contrast between them grows. Turn a cup over a bit of food and dogs go right for it, knocking the cup and revealing the treat. Dog subjects have even learned how to use a simple tool—pulling a string—to get an attached biscuit that was otherwise out of reach.

But dogs don't pass all the tests. They typically make lots of mistakes when presented with piles of three versus four biscuits, or of five and seven: they choose the smaller amounts just as often as the larger. And they develop preferences for piles on the left or the right, which lead them to make even more blatant errors. Similarly, their skill at finding hidden food gets worse as the hiding gets more complicated. And their tool use also starts to look less impressive as the trials get trickier. When there are two strings, and only the more distant one is attached to an alluring biscuit, dogs nonetheless go for the nearer string, the one attached to nothing. They don't seem to understand the string as a tool: as a means to an end. Indeed, they may have succeeded in the original case simply by pawing and mouthing at the problem until accidentally solving it.

A dog owner tallying her dog's score in these dog intelligence tests might find that he's scoring closer to
Dim but happy
than
Top of the obedience class.
Is that it, then? Is he not smart after all?

A closer look at the intelligence tests and the psychological experiments reveals a flaw: they are unintentionally rigged against dogs. The flaw is in the experimental method, not in the experimented dog. It has to do with the very presence of people—experimenters or owners. Let's look more closely at a typical experimental setup. It might begin as follows: A dog is sitting at attention and being restrained by a leash. An experimenter comes before him and shows him a great new toy. This dog loves new toys.* The toy and a bucket are clearly shown to the dog, the toy is put into the bucket, and then the experimenter disappears with the booty behind one of two screens in the room. She returns with the bucket—emptied of its treat. This turns out not to be a cruel hoax, but a standard test of
invisible
displacement:
wherein an object is
displaced
—moved to another location—
invisibly
—out of sight. This test has been regularly run with young children since Piaget proposed it as representing one of the conceptual leaps that infants make on their way to becoming incorrigible teenagers and then adults capable of having infants of their own. In this case, the conceptual understandings are of the continued existence of objects when they are out of sight—called
object permanence
—and some notion of that object's trajectory and continued existence in the world. If someone disappears behind a door, we realize not only that they still exist when we can't see them, but that we might find them by looking behind that door. Children master object permanence before their first birthday, invisible displacement by their second. Since Piaget reified this representational understanding as a stage in infant cognitive development, it is a standard test that is run with other animals, to see how they compare to little people. Hamsters, dolphins, cats, chimpanzees (who reliably pass), and chickens have all been tested. And dogs.

Dogs' performance is mixed. Oh, sure, if the test is run simply as described, then they have no trouble looking behind the screen for the toy. It looks as though they've passed the test. But complicate the scenario a little—carry the container behind two different screens, taking the toy out after the first screen
and showing
them that you have done so
before going behind the second screen—and dogs fail: they race to the second screen first, where the toy clearly is not. Other test variations also result in dogs suddenly looking less smart in their searching. We could conclude that here too the dogs appear to be less than genius. Once the toy is out of sight, it may quickly fall out of mind.

But the very fact that dogs do succeed, sometimes, renders that conclusion suspect. Instead their behavior points to two explanations. First, it is likely that dogs remember the toy, but do not engage in detailed consideration of what its path might be when it vanishes. Though some dogs are indisputably keen to keep track of a toy, dogs nonetheless regard objects in their environment very differently than humans do. Significantly, what wolves and dogs do with objects is limited: some objects are eaten, and some are played with. Neither interaction requires complex rumination on the object. Dogs realize when a previously treasured object is missing, but needn't mull over possible stories for what happened to it. Instead they just start looking for it, or wait for it to show up.

The second explanation is more far-reaching. It appears that the very skill at social cognition that is their triumph as a companion to humans contributes to the dogs' failure at this and other physical-cognition tasks. Show your dog a ball, then conceal it from him while you place it under one of two overturned cups. Faced with the cups, and assuming he can't smell it out, a dog will look under either cup at random: a reasonable approach when he has nothing to go on. Lift one cup to reveal a peek of the ball underneath, and you won't be surprised that when allowed to search, your dog will have no trouble looking under that cup. But give a peek under the cup holding nothing, and researchers found that dogs suddenly lose their logic. They search first under the empty cup.

These dogs were stymied by their own skill. When presented with a problem of any kind, dogs cleverly look to us. Our activities are sources of information. Dogs come to believe that our actions are relevant—often leading, we might note, to some interesting reward or even food. So if an experimenter ducks behind a second screen, as she does in the more complicated invisible displacement tasks, why, there might be something of interest behind that screen. If she lifts up an empty cup, that cup becomes more interesting simply because of her attention to it.

If the social cues are diminished in the tests, dogs perform much better. When experimenters handle both cups even when showing the dog the empty one, dogs regain their heads. They see the empty cup, and by deduction search under the other cup, which holds the hidden ball. Similarly, dogs who are less well socialized—such as
yard dogs
kept outside for most of their hours—also set right to the problem, while dogs who live inside the house more often plead quietly with their owners to help.