What a Dog's Tail Says About Its Mood

An Italian research team shows that other dogs can decipher and respond to the tail wags of other dogs.



Can you tell what mood your dog is in? Previous research has shown dogs wag their tails to their left if they're nervous, like when they encounter an aggressive dog, and to their right if they're happy, like when they see their owner. Now, the same Italian research team has discovered that other dogs can decipher and respond to those tail wags.



According to Professor Giorgio Vallortigara, a University of Trento neuroscientist, "It is very well known in humans that the left and right side of the brain are differently involved in stimuli that invokes positive or negative emotions." His research team wanted to see if that was the case with animals as well.

The new study had dogs view movies of other dogs wagging their tails, and recorded their heart rates and behavior. If the tail wagged to the left, the watching dog became nervous with an increased heart rate. If the tail wagged to the right, the watching dog remained calm.

Vallortigara doesn't believe dogs communicate through tail wags, but rather that they've learned from experience what movements are associated with what situations.