A recent study has uncovered an intriguing aspect of canine behavior: dogs react differently depending on the direction of a tail wag. According to the research, when dogs observe tails wagging to the right, they tend to be more at ease. While tails wagging to the left evoke a sense of stress. These responses are attributed to the varying functions of the left and right hemispheres of a dog’s brain.

Previous research by the same scientific team revealed that dogs exhibit rightward wagging when encountering something they wish to approach, like their owner. Leftward wagging in response to stimuli they want to retreat from, such as an aggressive posture from another dog.

Neuroscientist Giorgio Vallortigara of the University of Trento in Italy, who led both studies, explained that directional tail wagging manifests increased activation in either the left or right hemisphere of a dog’s brain.

Further Exploration

To investigate whether dogs discern the meaning behind tail wag direction, the researchers enlisted 43 dogs of various breeds. They showed these dog videos featuring another dog or a digitized silhouette of a dog wagging its tail to the left or right. The observing dogs had heart rate monitoring vests, and their behaviors were recorded and analyzed.

The findings revealed that when dogs observed leftward tail wagging, their heart rates increased, and they exhibited more signs of stress and anxiety. Conversely, they appeared more relaxed when witnessing rightward wagging. The study results were published in the journal Current Biology on October 31.

Vallortigara emphasized that while dogs may interpret tail wagging as stressful or non-stressful, it does not necessarily imply intentional communication. He suggested that it could simply result from one side of the dog’s brain being more activated.

Interpreting the Signals

Lesley Rogers, an emeritus professor of neuroscience at the University of New England in Armidale, Australia, who was not involved in the study, suggested that dogs might become more stressed when seeing a leftward tail wag because they perceive the other dog as being in a heightened state of arousal or more likely to attack.

Rogers, who has extensively researched right or left biases in animal brains, noted that the left hemisphere tends to be engaged during relaxed states. In contrast, the right hemisphere is activated in emergencies or during attacks.

advertisement