Whether it’s an elegant swish or a furious oscillation, tail wagging is ubiquitous among dogs. Now researchers have suggested that it may have become common during dog domestication because people like the rhythm of it.
It is believed that humans domesticated dogs sometime between 15,000 and 50,000 years ago – a process that led to a fierce bond between the two species, with approx. a third of UK households have a dog.
But while owners often rely on tail wagging to interpret how their dog might be feeling, it remains unclear exactly how such a canine semaphore evolved.
Now, experts have outlined a number of theories in an attempt to encourage researchers to delve into the issue.
“We may not be able to take a time machine back to the beginning of the dog-human relationship, but we can look at dog behavior today in tandem with human behavior to try to understand what that domestication process looked like,” Dr Taylor said. . Hersh, a co-author of the article, from Max Planck Institute for Psycholinguistics in the Netherlands.
“Tail wagging is a very distinct and interesting behavior to begin with.”
Write in the journal Biology LettersHersh and colleagues describe a number of studies that have previously looked at tail wagging.
Among them, experts found that hand-raised puppies wag their tails much more than hand-raised wolfdogs, and that dogs wag to their right in response to positive experiences – such as seeing their owners – and to their left when they want to withdraw, for example in aggressive situations.
However, questions remain, including why dogs wag their tails more often and in more contexts than other dogs.
One possible trigger, the team says, is the domestication process, with research previously suggesting that other traits in dogs arose because they have a genetic link to behaviors that humans were selected for – such as tameness or obedience. Hersh and colleagues say something similar may be at play for tail wagging.
But, they suggest, there may be another explanation.
“We put forward a new hypothesis that humans have consciously or unconsciously selected for tail wagging during the homing process because we are very attracted to rhythmic stimuli,” said Silvia Leonetti, first author of the paper.
The team are now calling for new investigations into tail wagging to explore the possibilities, with Leonetti adding that experiments using advanced and non-invasive technologies – focusing not just on single dogs but on dog-dog and dog -human interactions – can help shed further light on the act’s different meanings.
While the paper was welcomed by others, Dr Juliane Bräuer of the Max Planck Institute for Geoanthropology noted that it is possible that increased tail wagging was directly selected for by humans for reasons other than its rhythmic nature.
Dr Holly Root-Gutteridge, a dog researcher at the University of Lincoln, said she believed tail wagging was a social signal between individuals who adapted dogs to use with humans because people found barking annoying.
“We’re a highly visual species and can appreciate the rhythm, it’s an interesting thought to explore, although I’m not sure we really respond to it that much,” she said.
Root-Gutteridge added that wolves also wag their tails and used it as a social signal, although data was limited on its use in the wild.
“I suspect that ancestral humans saw tail wagging as a positive, easy-to-read sign in wolves, and developed it the way we talk with our hands – as a communicative gesture that we can easily understand.”