Scientists have long assumed that this ability of dogs has evolved from the experience of their ancestors, wolves that, as biologists know, have the capacity to read the language of the bodies of other wolves. " The direction of the tailing movements in the vial corresponds to the work of the hemisphere, which is commented on by Giorgio Vallorthigara from the centre of neuralouk at the University of Trento. So the dog is looking for another dog waving a tail on the right side: the left hemisphere is activated with positive emotional condition.
When a dog sees a hanging tail on the left side of a dog, she knows she's negative. The dog is activated by the right hemisphere, and it has negative emotions; the dogs watching it in turn feel alarmed " , reported in the last issue of the British Current Biology Scientific Journal.

Forty-three healthy homeworkers participated in the study different types of dogs♪ They were screened with dog films that kicked the tail to the left, and the scholars observed a change in the heartbeat of the experiment. The images were displayed, both in the usual form of " sodium " and only in the form of a dog. During the observation, it was observed that when a dog on the screen was kicking his tail to the left, the heartbeat of watching dogs increased, and their behaviour indicated that they were alarmed. And on the other hand, when the dog's tail on the screen was on the right side, the dogs became relaxed and calmed.
The asymmetry of the dog's tail motion explains the asymmetry of the brain, similar to that of a man, for example. Different emotions activate different brain hemisphere, which affects body movements.
In his previous studies, the same team of scholars has found that dogs, getting aggressive, were kicking their tail to the left, because the tailing movement to the left is controlled by a right-handed brain hemisphere, which scientists believe is responsible for processing emotional information, especially fear and anxiety, reports cell.com.
The involvement of the right hemisphere of the dog in the handling of threatening irritants was recently confirmed by a group of researchers from Lincoln University who found that dogs were turning their head to the left (which implies the management of the right hemisphere) when looking at a picture of an aggressive dog and rightly looking at the image of a happy dog.