Tail wagging in dogs certainly originates from their wolf ancestry. Wolves also communicate with their tails.
There are two specific styles of tail wagging that wolves perform: rigid or fluid movement. A rigid tail (like a pendulum) wag means the wolf is excited and has dominant tendencies. A fluid, or snake-like wag typically is a signal of play or greeting toward other pack members.
The elevation and movement of each wolf’s tail work together to describe the behavior of each individual. So, a wolf who is rigidly wagging a T1 tail is exhibiting intense dominance, however a wolf fluidly wagging a T3 tail is probably soliciting social play with other pack members.
But new research shows that in dogs, wagging on the left is quite different and communicates a different message to wagging on the right. Needless to say tail-wagging on the sinister side was a cause for concern to other dogs while a wag on the dexter side was reassuring!
Siniscalchi et al.: Current Biology, Seeing left or right asymmetric tail wagging produces different emotional responses in dogs, 10.1016/j.cub.2013.09.027
EurekAlert:The findings reported in the Cell Press journal Current Biology on October 31 show that dogs, like humans, have asymmetrically organized brains, with the left and right sides playing different roles.
The discovery follows earlier work by the same Italian research team, which found that dogs wag to the right when they feel positive emotions (upon seeing their owners, for instance) and to the left when they feel negative emotions (upon seeing an unfriendly dog, for example). That biased tail-wagging behavior reflects what is happening in the dogs’ brains. Left-brain activation produces a wag to the right, and right-brain activation produces a wag to the left.
While monitoring their reactions, the researchers showed dogs videos of other dogs with either left- or right-asymmetric tail wagging. When dogs saw another dog wagging to the left, their heart rates picked up and they began to look anxious. When dogs saw another dog wagging to the right, they stayed perfectly relaxed.
“The direction of tail wagging does in fact matter, and it matters in a way that matches hemispheric activation,” says Giorgio Vallortigara of the Center for Mind/Brain Sciences of the University of Trento. “In other words, a dog looking to a dog wagging with a bias to the right side—and thus showing left-hemisphere activation as if it was experiencing some sort of positive/approach response—would also produce relaxed responses. In contrast, a dog looking to a dog wagging with a bias to the left—and thus showing right-hemisphere activation as if it was experiencing some sort of negative/withdrawal response—would also produce anxious and targeting responses as well as increased cardiac frequency. That is amazing, I think.”
Not so implausible.
We take sticking out the left hand when greeting someone as not quite the proper thing to do. In Asia where the left hand is associated with cleaning oneself, the use of the left hand inappropriately could be taken as insulting. Monica Watkins writes, “Left-handedness has been, and in some cases still is, considered an inconvenience, a bad habit, or a symbol of the “sinister””. A Yale study just published also claims that left-handed people are more likely to have psychotic disorders such as schizophrenia. Another study claims that our handedness is a major subliminal influence in the choices and decisions we make in all aspects our daily lives.
And it might have sinister implications if the Queen were to start waving with her left hand.
A sinister wave?
And I wonder if dogs distinguish between humans who pat them with their right hands and those who use their sinister side?
The k2p blog 