When your dog bounds towards you with his tail wagging furiously, you’d naturally assume he was pleased to see you. Look closer, however, and that tail might be trying to tell you something very different.
While all dog tails wag from side to side, it seems they do so with a certain left or right bias depending on the message your pet is trying to convey. According to scientists a wag with a bias to the right signifies happiness, and a wag more to the left, fear. Because dogs move around so much, this often goes unseen by humans. Fellow dogs, however, are fully tuned into the subtle signalling.
An Italian team showed 43 dogs videos of other dogs whose tail wagging was more pronounced either towards the left or the right. When dogs saw another dog wagging more towards the left, their heart rates picked up and they began to look anxious. Dogs shown wagging biased to the right stayed perfectly relaxed.
Study leader Dr Giorgio Vallortigara, of the University of Trento, said: “a dog looking at 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 at 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”.
Each dog in the study was shown videos of another dog wagging its tail. Some clips were shown as darkened silhouettes to obscure features besides tail wagging that might have had an influence, such as facial expression. – Daily Mail