It seems (first link) that the information conveyed by a dog's wagging tail is chirally differentiated - that is to say, a wag to the left means something different from a wag to the right.

Specifically, if Fido's tail is moving mostly to his left, then he's more anxious than happy. (The report doesn't say whether there's a minority of left-handed dogs who wag anxiously to the right).

Now, back in 1967, Desmond Morris (The Naked Ape, pp.102-3) postulated that laughter is a combination of expressions of anxiety with those of relief - and experience tends to confirm this as a useful theory.

Meanwhile, even further back, Max Eastman observed that "Dogs laugh, but they laugh with their tails".

Clearly, then, a laughing dog is one whose tail moves through many degrees of arc on *both* sides of a tangent to its spine at some point near its pelvis.

A hardware device looped around the tail might cause some discomfort, so an array of cameras with image-analysis software would provide the most humane way to gather the basic data.

The metric would be defined at any given point in time in relation to the previous two inflection points on a notional graph of the movement of the dog's tail. At any given inflection point, a tangent to the tail at a given distance from the dog's pelvis will be at a certain angle to the tangent to its spine mentioned above. The metric would have the value of the smaller of those two angles, unless the tail were actually at rest, in which case the value of the metric would be zero.

The usefulness of this metric, which I have not yet named, will be most apparent to those stand-up comedians who specialize in making dogs laugh. I read a while ago that the turnover of the North American pet products industry is the same size as the entire GDP of the state of South Australia, so, if such comedians do not *yet* exist it is, surely, only a matter of time.
-- pertinax, Dec 07 2013

chiral wags http://www.bbc.co.u...nvironment-24746107
right - happy, left - bothered [pertinax, Dec 07 2013]

I'm familiar with Eastman but only aware of Morris. I spend a lot of times with dogs on a professional basis, know quite a bit about communicating with them, and frequently help owners get in better touch with their dogs' needs and desires. All of my experience with tailspeak (I hate that term) is related to the elevation, angle, and degree of curl. I've never spotted any trends relating to left- or right-tailed dominance, but now I'm going to start looking for it. [+] for possible new insight.

Also, while dogs do seem to 'laugh' with their tails, they also laugh with their mouths: the lips retract, the chops turn up, and the laugh comes out as an exaggerated exhalation, a rough panting or 'chuffing' sound. Not all dogs do this, just those with a sense of humor.
-- Alterother, Dec 07 2013


Do you attach any particular meaning to circular wagging, [Alterother]? I ask because my daughter is curious, and not out of any desire to set off any Dr Seuss-ish riff about chiral spiral fractal dactyls, nor any such nonsense as that.
-- pertinax, Dec 08 2013


// Do you attach any particular meaning to circular wagging //

As it happens, I do; a circular wag is what I call an 'honest' or 'open' wag because it usually comes from a dog who has lost track of what his tail is doing (or doesn't care). Tail pitch varies with breed, but generally a wide, flailing circular wag with tail raised and tip curling upward indicates unbridled idiot joy (this is usually when you get smiling, laughing, andor play initiation as well). On the other side, a hesitant little circle with tail down and tip pointed seems to be trusting uncertainty. If the latter is a regular behavior, it might be a sign of an underlying anxiety complex.
-- Alterother, Dec 09 2013


//left-handed dogs

Errr..they don't have hands, which is supposedly why we rule the planet and they are one step from becoming winter gloves.
-- not_morrison_rm, Dec 09 2013


They're left- or right-pawed. Never met an ambidextrous dog that I know of.
-- Alterother, Dec 09 2013


Thank you, [Alterother].
-- pertinax, Dec 10 2013


No sweat. Giving someone useful advice is a rare and happy event for me. What kind of dog does your daughter have?
-- Alterother, Dec 10 2013


It's not ours; it belongs to my in-laws. We also have a dog of our own, an English Cocker Spaniel, but the one she was wondering about was their ageing Border Collie.
-- pertinax, Dec 11 2013


I'm definitely not saying this applies to your in-laws' dog, but collie breeds (along with spaniels, setters, and pointers) can develop insecurity complexes that get...weirder...as they age. It can manifest as distrust of strangers, territorial behavior (esp. toward other dogs), extreme reluctance to leave home, and submissive urination. I see it all the time. Nothing against your dog, but I've been bitten by more spaniels than every other breed of dog combined, and most of those were Cockers.

On the other paw, many of them live happy lives with no anxiety at all, and they certainly aren't the only purebreeds that go wonky. You should see some of the St. Bernards I work with.
-- Alterother, Dec 11 2013


I like Beagles, handsome little buggers.
-- Zeuxis, Dec 11 2013



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