Inside of a Dog_ What Dogs See, Smell, and Know - Alexandra Horowitz [46]
This principle of antithesis—that opposing postures communicate opposing emotions—describes much of the expressive scope of dogs. Facial expressions, most visible in the mouth and ears, mind this principle, too. The mouth sweeps from closed to open and relaxed, to open with lips raised, snout wrinkled, and teeth bared. A dog's "grin," with jaw closed, is submissive; as the mouth is opened, the arousal increases; and if the teeth are exposed, the look gets aggressive. Coming full circle, a wide-open mouth with teeth mostly covered—a yawn—is not a sign of boredom, as often assumed by analogy with our own yawning; instead, it may indicate anxiety, timidity, or stress, and is used by dogs to calm themselves or others. The ears can also go through these gymnastics: they can be pricked, relaxed and down, or folded tightly along the head. Eyeballing another dog directly can be threatening or aggressive; by contrast, looking away is submissive—an attempt to quell one's own anxiety and the other dog's arousal. In other words, in each case there is a range from one extreme to another, representing variation in intensity along an emotional continuum, from relaxed to aroused in fear or alarm.
None of these is a static symbol—or, if it is, its being static is meaningful. Holding an erect posture, motionless, is a quiet way of putting an exclamation point on the posture. It exaggerates the tenseness of the communication. For the most part, postures are taken, and moved through. The tail, especially, is a limb of movement. It is to science's great discredit that no one has done a thorough investigation of the meaning of every wag of the dog's tail.
As a puppy her tail was trim, an arrow of soft black fur. This turned out not to be the destiny of her tail at all: it grew into an incredible banner of a tail, with extravagant feathering that matted and gathered leaves. It was bent at the tip from a disagreement with a car door when she was young. She brandished it when excited or delighted, curved to a sickle with the tip pointing at her back. When lying down, she drummed it happily on the ground at my approach. Her tail registered her exhaustion in a low-hanging straight pose; her disinterest in a nosy dog by tucking between her legs. Most of the time as we walked together, it hung loosely down, curving jauntily toward its tip, and merrily swished to and fro. I loved to approach her slowly, stalking her, and prompt her tail to quiver into wagging.
One of the difficulties in deciphering the language of tails is the great variation in tails among dogs. The flamboyant plumage of a golden retriever contrasts mightily with the tight corkscrew of the pug. Dogs wear tails long and rigid, stumpy and curled, hanging heavily or perpetually perked. The wolf tail is in some ways an average of the various breed tails: it is a long, slightly feathered tail, held naturally slightly down. Early ethologists who did a reckoning of wolf tail postures identified at least thirteen different tail carriages, conveying thirteen distinguishable messages. As per the antithesis thesis, tails held high indicate confidence, self-assertion, or excitement from interest or aggression, while low-hanging tails indicate depression, stress, or anxiety. An erect tail also exposes the anal region, allowing a bold dog to air his odor signature. By contrast, a long tail held so low as to curl back between the legs, closing off the rump, is actively submissive and fearful. When a dog is simply waiting around, his tail is relaxed, hanging low, dropped down but not rigid. A tail gently lifted is a sign of mild interest or alertness.
But it is not as simple as tail height, for the tail