Dogs wag their tails when excited. And even if they are not doing this consciously, those around them can use this movement to find out the dog’s emotional state. In fact, tail movement is one of the most important body signals dogs send out in social situations, and it is certainly the signal most people use to determine a dog’s intentions.
It can be compared to a situation that seems funny to us and where we start to laugh: we don’t do it on purpose, but other people can use our laughter to find out how we are feeling.
BUT IS IT SO EASY TO RECOGNIZE THE SENSE OF MOVING THE TAIL?
Many people believe that a dog wagging its tail has good intentions and are surprised if the dog’s behavior shows them otherwise.
In fact, dogs wag their tails to convey very different emotional states, from joy to irritation, threat, fear or insecurity. Therefore, it is important to pay attention to other signals the dog is wagging its tail, such as tail height, amount of movement, and tension, as well as signals it is communicating with other parts of the body, such as posture or vocalization.
How high is the tail erect?
In general, a high tail shows a confident posture, while a low tail is more likely to indicate insecurity. But when assessing the height of the tail, it is also important to pay attention to the usual position of the dog’s tail when at rest, as some dogs (like Spitz) keep the tail high even during normal relaxation.
HOW FAST DOES THE TAIL MOVE?
Another important aspect is the speed of movement: a faster movement indicates a higher arousal. Dogs get very excited when they move their tail so quickly and briefly that it looks like a vibration.
You should also judge whether the tail is relaxed or tense: A dog that makes a broad and relaxed tail movement, possibly with circles or with a wiggle of the hips, shows a friendly and playful posture. In contrast, an anxious or nervous dog tends to keep its tail low and move it rigidly. If the movement is tense and fast and the tail is up, the dog will display a threatening posture.
WHICH SIDE DOES THE TAIL MOVE?
Recent studies have shown that there is one more aspect to consider in order to understand the message of the tail wag: the direction of the wag. So a tail that moves primarily to the right is not the same as a tail that moves primarily to the left. This asymmetrical tail movement depends on a concept scientists call lateralization of the brain. Moving more to the left indicates that the right hemisphere has been activated, while moving to the right means the left hemisphere is activated.
Activation of the cerebral hemispheres depends on what the dog is looking at: the left side is activated when the animal is in a state of positive arousal, while the right side is associated with a tendency for the dog to avoid the situation. Often times, dogs looking at people they know will move their tails to the right, while dogs who are scary will move their tails to the left.
These differences in movement are not always easy for us to recognize, while dogs recognize these signs from one another exactly and react differently when encountering another dog, depending on the type of movement.
With a friendly dog, primarily with its tail moving to the right, dogs will react in a relaxed manner and try to approach each other. Instead, they are more likely to be anxious in a dog whose tail is tilted to the left.
THE TAIL IS USED FOR THE DOGS TO COMMUNICATE
Obviously, all of these signs are more noticeable when the tail is long, and not just to us but to other dogs as well: One study found that dogs are less likely to approach a dog with a short tail than a dog with a long tail, if one the long tail is moving and not immobile and tense. For example, shortening the tail can impair the clarity of dog communication and increase the risk of misunderstandings. Dogs with their tail cut off are at greater risk of engaging in aggressive encounters with other dogs.
Tail wagging is part of the nature of dogs. They inherited this behavior from the wolves, but with their domestication, their tendency towards this behavior has increased greatly.
Although the original function of tail movement was to maintain balance, over time this behavior has become an important form of dog communication. While puppies a few weeks old do not yet know how to wag their tails, by two months they have already mastered the movement and can perfect their use in various communication contexts. So it is our job to improve our ability to decipher the message hidden in the tail wag.