Dogs know a left-sided wag from a right

Oct 31, 2013
Credit: Siniscalchi et al.

You might think a wagging tail is a wagging tail, but for dogs there is more to it than that. Dogs recognize and respond differently when their fellow canines wag to the right than they do when they wag to the left. The findings reported in the Cell Press journal Current Biology on October 31 show that dogs, like humans, have asymmetrically organized brains, with the left and right sides playing different roles.

The discovery follows earlier work by the same Italian research team, which found that dogs wag to the right when they feel positive emotions (upon seeing their owners, for instance) and to the left when they feel negative emotions (upon seeing an unfriendly dog, for example). That biased tail-wagging behavior reflects what is happening in the dogs' brains. Left-brain activation produces a wag to the right, and right-brain activation produces a wag to the left.

But does that tail-wagging difference mean something to other dogs? Yes it does, the new study shows.

While monitoring their reactions, the researchers showed dogs videos of other dogs with either left- or right-asymmetric tail wagging. When dogs saw another dog wagging to the left, their heart rates picked up and they began to look anxious. When dogs saw another dog wagging to the right, they stayed perfectly relaxed.

This video is not supported by your browser at this time.
Dogs visual stimuli (naturalistic and silhouette) exhibiting prevalent left- or right-asymmetric tail wagging. Stationary stimuli not wagging their tail are also showed (pictures are single frames from moving videos). Credit: Current Biology, Siniscalchi et al.

"The direction of tail wagging does in fact matter, and it matters in a way that matches hemispheric activation," says Giorgio Vallortigara of the Center for Mind/Brain Sciences of the University of Trento. "In other words, a dog looking to a dog wagging with a to the right side—and thus showing left-hemisphere activation as if it was experiencing some sort of positive/approach response—would also produce relaxed responses. In contrast, a dog looking to a dog wagging with a bias to the left—and thus showing right-hemisphere activation as if it was experiencing some sort of negative/withdrawal response—would also produce anxious and targeting responses as well as increased cardiac frequency. That is amazing, I think."

Vallortigara doesn't think that the dogs are necessarily intending to communicate those emotions to other . Rather, he says, the bias in tail wagging is likely the automatic byproduct of differential activation of the left versus the right side of the brain. But that's not to say that the bias in wagging and its response might not find practical uses; veterinarians and dog owners might do well to take note.

This video is not supported by your browser at this time.
Dogs visual stimuli (naturalistic and silhouette) exhibiting prevalent left- or right-asymmetric tail wagging. Stationary stimuli not wagging their tail are also showed (pictures are single frames from moving videos). Credit: Current Biology, Siniscalchi et al.

"It could be that left/right directions of approach could be effectively used by vets during visits of the animals or that dummies could be used to exploit asymmetries of emotional responses," Vallortigara says.

Explore further: Danish museum discovers unique gift from Charles Darwin

More information: Current Biology, Siniscalchi et al.: "Seeing left or right asymmetric tail wagging produces different emotional responses in dogs." dx.doi.org/10.1016/j.cub.2013.09.027

Related Stories

How dog-savvy is your child?

Sep 02, 2012

(HealthDay)—Dog bites are one of the risks faced by children playing outdoors, but some simple safety measures can help protect them.

See spot see

Mar 02, 2013

(HealthDay)—It's a dog-see-dog world. With no sniffing involved, dogs can recognize the faces of other dogs among the faces of humans and other animal species, according to a new study.

Well-designed dog parks offer great benefit

Jul 01, 2013

Fenced specialty dog parks are offering great social and wellbeing benefits for both dogs and their owners - but they need to be well-designed for maximum gain, says a University of Adelaide veterinarian.

Dogs can sniff out lung cancer, pilot study shows

Dec 05, 2012

Dogs are surprisingly adept at sniffing out lung cancer, results from a pilot project in Austria published on Wednesday suggested, potentially offering hope for earlier, life-saving diagnosis.

Recommended for you

Danish museum discovers unique gift from Charles Darwin

Aug 29, 2014

The Natural History Museum of Denmark recently discovered a unique gift from one of the greatest-ever scientists. In 1854, Charles Darwin – father of the theory of evolution – sent a gift to his Danish ...

Top ten reptiles and amphibians benefitting from zoos

Aug 29, 2014

A frog that does not croak, the largest living lizard, and a tortoise that can live up to 100 years are just some of the species staving off extinction thanks to the help of zoos, according to a new report.

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

antonima
1 / 5 (6) Oct 31, 2013
Makes me think twice about those people who use the wrong hand to write.
MrVibrating
1 / 5 (1) Oct 31, 2013
And all them wrong 'uns who drive on the wrong side.

(The left side is the right side. The right side is the wrong side.)