Research Shows Dogs Communicate with Each Other Through Tail Wags! Previous research demonstrated that a wag to the right is indicative of positive emotions, while a wag to the left shows negative emotions. This new research shows that a dog will recognize and respond differently to another dog that wags to the left compared with one who wags to the right. To learn more, go to http://www.sciencedaily.com/releases/2013/10/131031124916.htm