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Snapple, an Australian shepherd (l), does a "play bow" during play with a terrier mix at a dog park in Arlington, Va. In the new book Citizen Canine, author David Grimm writes about research by Marc Bekoff at the University of Colorado. who studies dog play and what It can reveal.
A shaggy brown terrier approaches a large chocolate Labrador in a city park. When the terrier gets close, he adopts a yoga-like pose, crouching on his forepaws and hiking his butt into the air. The Lab gives an excited bark, and soon the two dogs are somersaulting and tugging on each other's ears. Then the terrier takes off and the Lab gives chase, his tail wagging wildly. When the two meet once more, the whole thing begins again.
Watch a couple of dogs play, and you'll probably see seemingly random gestures, lots of frenetic activity and a whole lot of energy being expended. But decades of research suggest that beneath this apparently frivolous fun lies a hidden language of honesty and deceit, empathy and perhaps even a humanlike morality.
Take those two dogs. That yoga-like pose is known as a "play bow," and in the language of play it's one of the most commonly used phrases. It's an instigation and a clarification, a warning and an apology. Dogs often adopt this stance as an invitation to play right before they lunge at another dog; they also bow before they nip ("I'm going to bite you, but I'm just fooling around") or after some particularly aggressive roughhousing ("Sorry I knocked you over; I didn't mean it.").
All this suggests dogs have a kind of moral code -- one long hidden to humans until a cognitive ethologist named Marc Bekoff began to crack it.
A wiry 68-year-old with reddish-grey hair tied back in a long ponytail, Bekoff is a professor emeritus at the University of Colorado at Boulder, where he taught for 32 years. He began studying animal behaviour in the early 1970s, spending four years videotaping groups of dogs, wolves and coyotes in large enclosures and slowly playing back the tapes, jotting down every nip, yip and lick. "Twenty minutes of film could take a week to analyze," he says.
The data revealed insights into how the animals maintained their tight social bonds -- by grooming each other, for example. But what changed Bekoff's life was watching them play. The wolves would chase each other, run, jump and roll over for seemingly no other reason than to have fun.
Few people had studied animal play, but Bekoff was intrigued. "Play is a major expenditure of energy, and it can be dangerous," he says. "You can twist a shoulder or break a leg, and it can increase your chances of being preyed upon. So why do they do it? It has to feel good."
When Bekoff began looking at videos of dogs romping in super-slow motion, he began to realize there was more going on in the canine mind than science had acknowledged. He noticed the "play bow," for example.
What's more, he found canines "role-reverse" or "self-handicap" during play. When a big dog played with a smaller one, for example, the big dog often rolled on her back to give the smaller dog an advantage, and she allowed the other dog to jump on her far more often than she jumped on him.
Bekoff also spotted a number of other blink-and-you'd-miss-them behaviours, such as a sudden shift in the eyes -- a squint that can mean "you're playing too rough" -- and a particular wag of the tail that says, "I'm open to be approached." Humping a playmate during a romp, meanwhile, was often an invitation to nearby dogs to come join the fun.
Such signals are important during play; without them, a giddy tussle can quickly turn into a vicious fight.
In the wild, coyotes ostracize pack members that don't play by the rules. Something similar happens in dog parks: If three dogs are playing and one bites or tackles too hard, the other two are likely to give him the cold shoulder and stop playing with him, Bekoff says. Such behaviour, he says, suggests dogs are capable of morality, a mindset once thought to be uniquely human.
Even morality hints at something deeper, however. To enforce moral conduct, dogs must be able to experience a spectrum of emotions, from joy to indignation, guilt to jealousy. They must also be able to read these emotions in others, distinguishing accident from intent, honesty from deceit.
Scientists have found that dogs trained to shake hands with humans will stop shaking if they notice they aren't being rewarded for the trick although a nearby dog is -- a sign, the researchers suggested, that dogs can sense inequity.
Other studies have revealed that dogs yawn when they see humans yawning and that they nuzzle and lick people who are crying; scientists consider both behaviours displays of empathy, a rarely documented trait in the animal kingdom.
Bekoff's recent work suggests another remarkable canine skill: the ability to know what another animal is thinking -- a "theory of mind."
Dogs seem to display a rudimentary form of this skill during play. He has noticed, for example, one dog won't begin trying to play with another dog until he has her attention. To get her to notice, he may nip the other dog or run into her field of view. That, Bekoff says, shows the one wanting to play knows she's not paying attention to him. Though this may seem like a simple skill, it's incredibly important to our species. Without it, we can have a hard time learning or interacting with the world around us.
Interestingly, dogs even outsmart chimpanzees on some theory-of-mind tests. When a researcher points at one of two cups, for example, dogs almost always run to the cup that is pointed to, a sign that they have intuited what the scientist was thinking -- i.e., that the researcher was trying to show the dog something. Chimps, by contrast, have no idea what we mean when we point at something.
"Dogs have an amazing relationship with us, and Marc (Bekoff) has done a beautiful job helping us understand them," says Brian Hare, a biological anthropologist at Duke University and one of the world's foremost experts on canine cognition. "Play gives us a peek inside their heads and helps us understand how they became the species they are today."
Hare, one of the first scientists to show dogs could understand human pointing while chimpanzees could not, says Bekoff's studies add a new dimension to the canine personality: Dogs aren't just smart, they're also emotionally complex. "That's why we can have such a deep relationship with them," says Hare.
"When we study play in dogs," Bekoff says, "we study ourselves."