When a pet parent sees a dog wag his tail, it typically just tells us that the dog is happy.
When a dog sees another dog wag his tail, it might mean something entirely different, depending on which way the tail wags.
A new study, conducted by various researchers at universities in Italy, and published in the Current Biology, suggests that dogs react differently to a tail wagging to the left vs. a tail wagging to the right.
The research included 43 dogs, which all wore vests to monitor their heart rate. The dogs then watched special images of other dogs, which intended to remove stimuli from their brains, except for the tail wagging.
The canines were then shown a silhouette of a dog wagging its tail to the right. The dogs stayed calm. However, when the dogs were shown the dog wagging his tail to the left, the dogs heart rate increased and they became more anxious.
Canine behavior researchers believe this new study to be an important step in helping us understand canine behavior. “The finding that dogs are sensitive to the asymmetric tail expressions of other dogs supports the hypothesis of a link between brain asymmetry and social behavior and may prove useful to canine animal welfare theory and practice,” reports Current Biology.
Giorgio Vallortigara of the University of Trento in Italy, who has done previous studies on tail wagging, including a 2007 study which first proved dogs wag their tails in different directions to convey different emotions summed it up, “If you are going to visit a dog, if you are vet, there will be probably a side which is better with respect to the probability to evoke a more friendship response or to evoke a more aggressive response,” he told NPR.
Video: Roxanne Palmer YouTube Page credit of Current Biology, Siniscalchi et al
Have you ever paid attention to which side your dog is wagging its tail?