What Is the Meaning of Tail Wags in Dogs?

One of the most telling signs of how a dog feels is tail wagging. It was once thought that if a dog wagged his tail, it simply meant he was happy; however, there are many factors to consider if trying to interpret a tail wag, including whether the wag is predominantly to the right or left as well as the body position of the dog.

  1. History

    • Originally, a dog used his tail primarily for balance. Over time, he developed the ability to use the tail as an expression of emotion.

    Considerations

    • Some considerations when identifying the meaning of a wag are things such as stance. For example, an erect stance with tail wagging signifies positive emotions while a low stance, or head down and tail wagging indicates negative emotions. If a dog wags his tail high in the air, he is signaling dominance.

    Misconceptions

    • Typically, a dog will wag his tail excessively when he sees his master; however, he may also wag when approached by strangers.

    Recent Developments

    • According to a 2007 study by Giorgio Vallortigara of the University of Trieste in Italy, the direction of the tail wag pinpoints either a positive or negative reaction to stimulus. If a dog's tail is wagging predominantly to the right, he is signifying positive emotions. If he wags predominantly to the left, then he is expressing negative emotions.

    Significance

    • The discovery that dogs express different emotions depending on which way their tails wag is important because it shows "emotional asymmetry", similar to what humans possess. In other words, left brain activity is associated with positive emotions and controls the right side of the body. Right brain activity signifies more negative emotions and controls the left side of the body.