The tail wags the dog
Giorgio Vallortigara, a neuroscientist at the University of Trento, has come to the conclusion that happy dogs wag their tails more vigorously to the right whilst anxious ones wag to the left and that other dogs appear to respond to that. Dogs in his tests were happy when they saw food or their owners and stressed when they saw aggressive looking dogs. He then fitted 43 dogs with heart monitors and showed them films of dogs with tails wagging one way or the other. When they saw the left-tailers, the observing dogs' heart rate increased, they looked away and lifted their paws.
He also concludes that left-brain activation causes the tail to wag to the right and right-brain activation drives the tail to the left. This leads him to suggest that if you want a good response from a dog, you should approach it from its left-hand side.
What do my doggy readers think?