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: Keep dogs and cats safe during winter

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

Keep dogs and cats safe during winter

Dec 27, 2014

(HealthDay)—Winter can be tough on dogs and cats, but there are a number of safe and effective ways you can help them get through the cold season, an expert says.

Scientists target mess from Christmas tree needles

Dec 26, 2014

The presents are unwrapped. The children's shrieks of delight are just a memory. Now it's time for another Yuletide tradition: cleaning up the needles that are falling off your Christmas tree.

The ants that conquered the world

Dec 24, 2014

About one tenth of the world's ants are close relatives; they all belong to just one genus out of 323, called Pheidole. "If you go into any tropical forest and take a stroll, you will step on one of these ...

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.)

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.