A dog cares deeply, which way your body is leaning. Forward or backward? Forward can be seen as aggressive; backward—even a quarter of an inch—means nonthreatening. It means you’ve relinquished what ethologists call an “intention movement” to proceed forward. Cook your head, even slightly, to the side, and a dog is disarmed. Look at him straight on and he’ll read is like a red flag. Standing straight, with your shoulders squared rather that slumped, can mean the difference between whether your dog obeys a command or ignores it. Breathing evenly and deeply, rather than holding your breath can mean the difference between defusing a tense situation and igniting it. “I think they are looking at our eyes and where our eyes look like,” the ethologist Patricia McConnell, who teaches at the University of Wisconsin, Madison, says, “A rounded eye with a dilated pupil is a sign of high arousal and aggression in a dog. I believe they pay a tremendous amount of attention to how relaxed our face is and how relaxed our facial muscles are, because that’s big cue for them with each other. Is the jaw relaxed? Is the mouth slightly open? And then the arms. They pay a tremendous amount of attention to where our arms go.”

　　In the book?The Other End of the Leash,?McConnell decodes one of the most common of all human-dog interactions, the meeting between two leashed animals in a walk. To us, it’s about one dog sizing up another. To her, it’s about two dogs sizing up each other after first sizing up their respective owners. The owners “are often anxious about how well the dogs will get along,” she writes, and if you watch them instead of the dogs, you’ll often notice that the humans will hold their breath and round their eyes and mouths in an “on alert” expression. Since these behaviors are expressions of offensive aggression in a canine culture, I suspect the humans are unwittingly signaling tension. If you exaggerate this by tightening the leash, as many owners do, you can actually cause the dogs to attack each other. Think of it: the dogs are in a tense social encounter, surrounded by support from their own pack, with the humans forming a tense, staring, breathless circle around them. I don’t know how many times I’ve seen dogs shift their eyes toward their owner’s frozen faces and then launch growling at the other dog.

A dog is read to attack when _____.

• A.its eyes are diluted and rounded
• B.its owner’s body leans backward
• C.its owner’s shoulder squared
• D.its owner’s shoulder slumped