Inside of a Dog: What Dogs See, Smell, and Know

by Alexandra Horowitz

There is a final, seemingly minor difference between the two species. This one small behavioral variation between wolves and dogs has remarkable consequences. The difference is this: dogs look at our eyes.

In both species, eye contact can be a threat: to stare is to assert authority. So too is it with humans. In one of my undergraduate psychology classes, I have my students do a simple field experiment wherein they try to make and hold eye contact with everyone they pass on campus. Both they and those on the receiving end of their stares behave remarkably consistently: everyone can’t wait to break eye contact.

In a related experiment, they test gaze in a second way, verifying our species’ tendency to follow the gaze of others to its focal point. A student approaches any publicly visible and shared object—a building, tree, spot on the sidewalk—and looks fixedly at one point on it.

If this behavior is unsurprising, it is because it is so human: we look. Dogs look, too.

We not only avoid eye contact with strangers, we rely on eye contact with intimates.

Hence a dog’s ability to find and gaze at our eyes may have been one of the first steps in the domestication of dogs: we chose those that looked at us.

Mutations, variation, and admixtures are generally good for populations, though, and help to prevent inherited disease: this is why purebred dogs, though they come from what is considered “good stock” in that the ancestry of the dogs is traceable through the breeding line, are more susceptible to many physical disorders than are mixed-breed dogs.

there is one thing that may account for the variability in behavior between breeds. They have different threshold levels to notice and react to stimuli.

No gene develops right into retrieving behavior—or into any particular behavior at all. But a set of genes may affect the likelihood that an animal acts in a certain way.

Their threshold to respond to this motion is much lower than for dogs not bred to be hunting companions.

Similarly, a sheepdog who will spend his life herding sheep is one who has a certain set of specific tendencies: to notice and keep track of individuals of a group, to detect the errant motion of a sheep moving away from the herd, and to have a drive to keep

ANIMALS WITH AN ASTERISK

There is a tension between those who consider dogs wild animals at their core and those who consider dogs creatures of our own making.

The first group tends to turn to wolf behavior

the second group, which treats their dogs as quadrupedal, slobbery people.

calling a dog just an animal, and explaining all dog behavior as emerging from wolf behavior, is incomplete and misleading. The key to dogs’ success living with us in our homes is the very fact that dogs are not wolves.

dogs emerged from wolflike ancestors, and wolves form packs. Thus, it is claimed, dogs form packs. The seeming naturalness of this move is belied by some of the attributes we don’t transfer from wolves to dogs:

the wild, wolf packs consist almost entirely of related or mated animals. They are families, not groups of peers vying for the top spot.

rank is a mark of age.

What domestic dogs do seem to have inherited from wolves is the sociality of a pack: an interest in being around others. Indeed, dogs are social opportunists. They are attuned to the actions of others, and humans turned out to be very good animals to attune to.

We do better to explain dogs’ taking commands from us, deferring to us, and indulging us by the fact that we are their source of food than by reasoning that we are alpha.

We and our dogs come closer to being a benign gang than a pack: a gang of two (or three or four or more). We are a family. We share habits, preferences, homes; we sleep together and rise together; we walk the same routes and stop to greet the same dogs. If we are a gang, we are a merrily navel-gazing gang, worshiping nothing but the maintenance of our gang itself. Our gang works by sharing fundamental premises of behavior.

Wolves seem to learn from each other not by punishing each other but by observing each other. Dogs, too, are keen observers—of our reactions. Instead of a punishment happening to them, they’ll learn best if you let them discover for themselves which behaviors are rewarded and which lead to naught.

Punishing the dog for his misbehavior—the deed having been done maybe hours before—with dominance tactics is a quick way to make your relationship about bullying. If your trainer punishes the dog, the problem behavior may temporarily abate, but the only relationship created is one between your trainer and your dog.

Instead, let the dog use his observation skills. Undesired behavior gets no attention, no food: nothing that the dog wants from you. Good behavior gets it all. That’s an integral part of how a young child learns how to be a person. And that’s how the dog-human gang coheres into a family.

Sniff

Mute

Dog-eyed

But color plays a much less important role for them than it does for humans, and their retinae are why.

Dogs have only two: one is sensitive to blue and the other to greenish-yellow. And

As they do not experience a great range of distinct colors, dogs rarely show color preferences.

It may be meaningful that your dog attacks and pops all the blue or red balloons left over after the birthday party winds down: they are most distinct among a sea of pastels.

Dogs make up for their dearth of cones with a battery of rods, the other kind of photoreceptor in the retina. Rods fire most in low-light situations and at changes in light densities, which is seen as motion.

You can make that ball your dog is not seeing directly in front of him magically appear by giving it a little shove. Acuity greatly improves for close objects when they are bouncing.

The rate at which the cells do this leads to what is called the “flicker-fusion” rate: the number of snapshots of the world that the eyes take in every second.

sixty still images every second, which is our flicker-fusion rate.

Dogs also have a higher flicker-fusion rate than humans do: seventy or even eighty cycles per second.

This—and the lack of concurrent odors wafting out of the television—might explain why most dogs cannot be planted in front of the television to engage them. It doesn’t look real.*

One could say that dogs see the world faster than we do, but what they really do is see just a bit more world in every second.

Excepting a few phenomenal outfielders, dogs actually see the Frisbee’s, or the ball’s, new location a fraction of a second before we do.

Our responses to the world are a split second behind the dogs’.

Seen by a Dog

us, they pay attention to humans: to our location, subtle movements, moods, and, most avidly, to our faces.

animal cognition, which asks what an animal subject understands about the “mental states” of others.

animal cognition researchers look for behaviors that indicate that an animal is using attention.

non-human animals use eye contact. Between apes, eye contact is steeped with importance: it can be used as an aggressive action, and will be avoided by a submissive member of a troop.

wolves, too, a direct stare may be taken as a threat. So the “aggressive” element of eye contact is the same as with humans.

Thus we can expect that dogs might act somewhat differently than we do with regards to mutual gaze.

But wait! Dogs do look at our faces. They look at each other in the center of the face: at eye level. Most dog owners will report that their

we can say that a dog and human “mutually gaze” when we turn our faces toward each other.