When humans see a dog wagging its tail, we pretty much equate that with a happy dog. It turns out that a dog's tail may be much more expressive than we realize. Research has shown that happy dogs tend to wag more to the right, while anxious dogs go more to the left. A new study published in the journal Current Biology delves into the question of whether other dogs read this response.
This asymmetry of wagging is traced back to left- and right-brain action. Researchers showed dogs videos of other dogs, or silhouettes of dogs wagging their tails, with a preference in one direction or another. The viewing dogs had their heart rates measured and were monitored for their responses.
When the dogs saw other dogs with tails wagging primarily to the right, they stayed relaxed. When the tails tended to the left, their heart rates rose and they exhibited signs of anxiety. The researchers used 43 dogs for the study, ranging from purebreds to mutts.
"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," reads the study's abstract.
The study could also open a new window of insights for dog owners, perhaps encouraging them to think more like their canine companions. That wagging tail may not be all about fun and games.