Anyone who has owned dogs or spent much time watching them is familiar with the posture: hind end up, chest down on the ground, forelegs stretched forward, an eager expression on the face. It's obviously a friendly, playful gesture, and for most dog lovers, that's all you need to know. Ethologists--animal-behavior experts--go a step further. They call this move the "play bow" and know it's used not just by dogs but also by wolves and coyotes to signal an interest in the romping, pretend-fighting sort of games that canines of all kinds seem to love.
But Marc Bekoff, an ethologist at the University of Colorado, always suspected there was something more going on. True, the posture happens most often at the beginning of a bout of canine play. But it also happens in the middle, and not randomly. And the more closely Bekoff observed dog behavior, the more he began to recognize other ritualized motions and postures--some of them so fleeting that he couldn't really keep track. So he began making videotapes, then playing them back one frame at a time. "The more details I saw, the more interesting it got," he recalls. "It wasn't just dogs playing; it was also dogs exchanging an incredible amount of information as they played."
In short, Bekoff was able to show--after at least a decade of painstaking observation and analysis--that canine play is actually a complex social interaction in which the participants constantly signal their intentions and check to make sure their behavior is correctly interpreted. Dogs that cheat--promising a playful bite but delivering a harsh one, for example--tend to be ostracized.
That understanding is nothing short of revolutionary. Only a decade or so ago, scientists were arguing vigorously over whether animals had emotions: just because a dog looks sad or a chimp appears to be embarrassed doesn't mean it really is, the skeptics said. That argument is pretty much over. The idea of animal emotion is now accepted as part of mainstream biology. And thanks to Bekoff and other researchers, ethologists are also starting to accept the once radical idea that some animals--primarily the social ones such as dogs, chimps, hyenas, monkeys, dolphins, birds and even rats--possess not just raw emotions but also subtler and more sophisticated mental states, including envy, empathy, altruism and a sense of fairness. "They have the ingredients we use for morality," says Frans de Waal, a professor of primate behavior at Emory University in Atlanta, referring to the monkeys and chimps he studies.
That doesn't mean animals necessarily have a fully developed moral or ethical sense. "I don't say dogs are fair the way you and I are fair, or have the same moral systems," says Bekoff. But it does mean that-- just as with so many other attributes once considered unique to humans, including toolmaking and language--animals have at least rudimentary versions of what we call morality. That would conform to Darwin's ideas of evolution, and indeed, Darwin himself was convinced this must be true. "It would be bad evolutionary biology," says Bekoff, "to assume that moral behavior just pops on the scene only with us."