Sunday, 29 April 2007

It's all in the tail

Every dog lover knows how a dog expresses its feelings.
Ears close to the head, tense posture, hackles up and tail straight out from the body means “Watch it. Don’t mess with me”. Ears perked up, wriggly body and vigorously wagging tail means “I am sooo happy to see you!”
But there is another, newly discovered, feature of dog body language that may surprise attentive pet owners and experts in canine behaviour. When dogs feel fundamentally positive about something or someone, their tails wag more to the right side of their rumps. When they have negative feelings, their tail wagging is biased to the left.
A recent study at the University of Trieste confirms this and goes on to conclude that this intriguing observation confirms emotional asymmetry in the brain.
To reach this conclusion 30 family pets of mixed breeds were tested. They were placed in a cage equipped with cameras that precisely tracked the angle of their tail wags. Then they were shown four stimuli through a slat of the cage: their owner, an unfamiliar human, a cat and an unfamiliar dominant dog. When the dogs saw their owners, their tails wagged vigorously with a bias to the right of their body. Their tails wagged moderately, again, more to the right, when faced with an unfamiliar human and with a cat.
When the dogs looked at an aggressive, unfamiliar dog — a large Belgian shepherd Malinois — their tails all wagged with a bias to the left side of their bodies.
Thus when dogs were attracted to something, including a benign, approachable cat, their tails wagged right, and when they were fearful, their tails went left. It suggests that the muscles in the right side of the tail reflect positive emotions while the muscles in the left side express negative ones.
While some researchers have argued that only humans show brain asymmetry, strong left and right biases are showing up in the brains of many so-called simpler creatures such as the dog.
Information from the body to the brain that prompts an animal to slow down, to eat, relax and restore itself is biased towards the left brain. Whereas information that tells an animal to run, fight, breath faster and look out for danger is biased towards the right brain. In this way, the researchers argue, animals are naturally designed to cope with changing environments.
This study was published in The New York Times.


jmb said...

Well that's an interesting conclusion. Although from a study with only 30 it is a bit hard to make a hard and fast conclusion. Perhaps they will continue this study with a larger group. Still no doubt of great interest.

I, like the view said...

please come and wag your tail at my birthday party tomorrow. . .

it would be lovely to see you and belle!


Winchester whisperer said...

How very interesting. Have you tested this on your own dogs?

Eurodog said...

Yes I have and it seems to be so.