“To his dog, every man is Napoleon, hence the constant popularity of dogs.”  Aldous Huxley

Near as we can figure it, Homo sapiens sapiens and Canis lupus familiaris have been bffs for about 35,000 years.

After sampling the genomes of wolves and dogs from hither and yon, scientists now believe the unique and intimate association between Man and Dog began at least 15,000 year earlier than previous supposed somewhere in Southeast Asia with the domestication of the Taimyr wolf. Given the long stretch of time since then, you’d think we’d have learned just about everything there is to know about our four-legged besties. In fact, until very recently our understanding of humankind’s closest animal companion has been remarkably superficial, a two-dimensional portrait more closely resembling ourselves than our pets.

True, humans quickly became adept at dog-handling. They used their animals to guard the camp and to bring down the mighty mammoth. They taught the doting beasts to watch the flock and fight by their side in battle. And they carefully and patiently bred their dogs to satisfy specific human needs and tastes, resulting in the more than 300 breeds that exist today. One thing people never did, though, is give any serious thought to what their dogs thought about it all.

“Dogs have been used as tools, and they’ve been kept as pets, but there’s been very little study of what makes them tick,” explains canine clinician Jean Weller. “We know a lot about what they do, but not why they do it. It’s only in the last 25 years that there’s been any real scientific research into the emotional and cognitive characteristics of dogs.”

Considering the bone-deep affinity that exists between peeps and pups, it’s hardly surprising that we tend to ascribe human motivations to our pets. For example, most dog-lovers assume that their beloved beagle wags its tail when it sees them because it loves them right back. Scientifically speaking, that’s taking a lot on faith. Is your dog really glad to see you? Or is it just excited because it’s almost supper time and you’re the only one who can operate the can opener?

While standard observation has softened the rigid “alpha” pecking order into a more flexible canine social hierarchy, neither has much to do with you and your dog. Behavioral research increasingly suggests that the relationship between person and pet is less leader-to-follower or peer-to-peer, and more akin to the bond between parent and toddler. To cite just one example, when frightened or distressed a dog will always and instantly run to its owner for reassurance. Dogs are also prone to jealousy. Studies indicate that when a dog’s owner showers undue attention on a third party, be they man or beast, more than 60 percent of the time the dog will find some quiet, sneaky way to disrupt that interaction and redirect its master’s interest back where it belongs.

Probably the most intriguing discovery on the canine front is that dogs can infer. It’s a simple thing, inference, and incredibly useful. Merriam-Webster defines it as the ability to “deduce or conclude from evidence and reasoning rather than from explicit statements.” Humans infer a thousand times a day without consciously thinking about it. And yet our closest evolutionary relatives, chimpanzees, can’t infer. Of all creatures, only people and dogs are able to predict an event or circumstance based purely on observation. It’s how your dog knows when the mailman is coming. It’s how it can tell you’re hiding a snack behind your back. And it’s why, even though you take your dog to the park every day at 2 o’clock, you can’t get it into the car for a 2 o’clock veterinarian appointment.

Curiously enough, dogs also have a well-developed sense of fairness. Austrian researchers devised a scenario whereby two dogs were made to perform the same trick, but only one was rewarded for it. The un-rewarded dog invariably began scratching and licking itself in frustration until the account was balanced. Interestingly, the quality of the belated reward didn’t appear to matter. Even if the first dog received sausage, the second was perfectly satisfied to be given bread. It was, it seems, the principle of the thing.

Three hundred and fifty centuries later and we’re only now finding out that our dogs know when they’re getting the shaft. There’s still a world of work to do, but early results paint a far richer, nuanced and loveable picture of Man’s Best Friend than the one we’ve been looking at since Paleolithic times. On the other hand, not every discovery has come as a surprise.

Neuro-imaging studies conducted by animal cognition researchers at Emory University have learned that the scent of its human master lights up the “reward center” of a dog’s brain, just as the appearance of a loved one does in ours. What’s more, canine MRI results suggest that, of all the complex universe of odors packed into their daily experience, dogs prioritize human scent above all others.

Those big floppy ears aren’t for nothing, either. Scientists at Eotvos Lorand University in Budapest find that dogs are equally attuned to human vocal signals. Just as in people, “happy” sounds spark a pleasurable commotion in a dog’s auditory cortex, while negative noise tends to depress. And when your dog cocks its head to one side, it’s not doing it just to be cute. Dogs, we now know, are keenly sensitive to our every stance and movement. When in doubt of your emotional status, your pup will shift its head to remove its snout from its line of vision, allowing it to examine nonverbal cues from the top of your head to the tips of your toes. Taking these findings together, scientists conclude that dogs aren’t merely skilled at perceiving and responding to your every temper and emotion, they’re biologically hard-wired to do so.

In other words, your dog really is glad to see you.

“I am convinced that basically dogs think humans are nuts.”  John Steinbeck