It’s not joy, it’s people pleasing: why dogs wag their tails

Many of us have been there — the tense moment when you are visiting a friend or family who have a dog whose bite promises to be as scary as their bark.

While they might claim “he's harmless, he doesn't bite”, many believe one way of determining if that statement is true is to check if the dog is wagging its tail.

Many assume a swishing tail is a sign of a jubilant canine, but a recent story in The Guardian argues that might not be the case.

Experts have reportedly found concrete evidence to suggest dogs wag their tails to please humans.

“We put forth a new hypothesis that humans consciously or unconsciously selected tail wagging during the domestication process because we are very attracted to rhythmic stimuli,” said Silvia Leonetti, researcher and first author of the article. 

Unable to trace how these behaviours evolved when dogs were being domesticated, they found a link between dogs attempting to please potential breeders due to their propensity to be docile and tame. One of their findings suggests dogs will typically wag their tails to the right for humans they are familiar with, such as their owners, or to the left when aggravated.

University of Lincoln dog researcher Dr Holly Root-Gutteridge told The Guardian dogs lean into tail wagging as a “social signal because people found barking irritating”.

However, wagging tails is not the only signal we may have misconstrued.

The New York Times suggests many dog owners often miss signs of distress. Experts suggest dogs often show behaviours such as yawning, licking their lips or lifting their front paws as a signal.

Bigger indicators can be seen when they shed hair, scratch, pant, pace, or show you more of the whites of their eyes. Dog psychologist Sarah Byosiere said you have to view these signs in the context of the dog's situation.

Dog owners also often make the mistake of assuming their pets are extroverted.

“People who love dogs love to meet new dogs. But not all dogs like to meet new people or dogs,” said Brian Hare, an evolutionary anthropologist at Duke University who founded their Canine Cognition Center.

He told The New York Times the best approach when greeting a dog is to kneel or crouch and see if the dog approaches you.