Dogs mirror stress levels of their owners

The owner's personality was the most important factor in examining the stress-hormone relationship between pet and owner.

  • A new study found that dogs and their owners show similar levels of the stress hormone cortisol over time.
  • The dog-owner cortisol relationship seems to be related to the owner's personality, as measured by the Big 5 model.
  • Ultimately, dog owners needn't worry that they're stressing out their pet; not all cortisol indicates "bad" stress."


Just how empathetic are dogs?

A new study published in Scientific Reports suggests that dogs mirror the stress levels of their owners. The study examined levels of cortisol — a stress hormone — as measured in hair samples taken from owners and their dogs: 25 border collies and 33 Shetland sheepdogs. Results showed a "significant interspecies correlations in long-term stress."

"This is the first time we've seen a long-term synchronization in stress levels between members of two different species," Lina Roth, an ethologist who led the work at Linköping University in Sweden, told The Guardian.

But surely other factors — how long dogs spent alone, whether they had a garden to play in, how much physical activity they got — also played a big role in stress levels, right? Not so much. What's more, the dog's own personality — as measured by an owner-answered questionnaire — didn't seem to have a significant effect on cortisol levels either.

What did matter was the owner's personality. After participants answered questions from the Big 5 personality inventory, the researchers found that the personality traits neuroticism, conscientiousness, and openness were strongly correlated with owner-dog cortisol levels. Owners that were more conscientious and open had dogs with higher cortisol levels, but only in the winter. Meanwhile, neuroticism was most strongly correlated with dog cortisol levels — both in the winter and the summer.

However, only female dogs' cortisol levels increased when their owners scored high in neuroticism; male dogs with neuroticism-prone owners actually had lower cortisol levels.

Why? Possibly because neurotic owners tend to seek more comfort from their dogs, causing the pets to feel less stress.

"There is some indication that humans scoring high on neuroticism form a strong attachment bond to their dogs and that these individuals, to a greater extent than others, use their dog as a social supporter whilst also simultaneously functioning as a social supporter for their dog," the researchers wrote. "This, in turn, may lead to a positive modulation of the stress response for both parties."

Roth et al.

The researchers also compared two sets of dogs: those who compete in shows, and companion pets. The results showed a stronger correlation between the competition pets and owners, possibly because competitions foster a strong relationship between the two.

"Dogs are affected by their owners' distress and respond with consoling behaviours," James Burkett at Emory University, who wasn't involved in the study, told The Guardian. "We now know that dogs are also affected by their owners' personalities and stress levels. While this may be common sense for dog owners, empirical research is still catching up to our intuitions about animal empathy."

So, does this mean you should feel guilty about stressing your dog out if you share the personality traits of the owners in the study? Not at all. Roth told The Associated Press that cortisol doesn't always indicate negative stress — it could just be a dog getting excited before going on a walk. Additionally, she noted that researchers are still studying the relationship between owner-dog stress levels, and it's possible that dogs might hold some effect on owners' stress levels as well.

Ultimately, her advice is simple: "Just be with your dog and have fun."

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  • Domino's partnered with the Silicon Valley startup Nuro to have robot cars deliver pizza.
  • The trial run will begin in Houston later this year.
  • The robots will be half a regular car and will need to be unlocked by a PIN code.

Would you have to tip robots? You might be answering that question sooner than you think as Domino's is about to start using robots for delivering pizza. Later this year a fleet of self-driving robotic vehicles will be spreading the joy of pizza throughout the Houston area for the famous pizza manufacturer, using delivery cars made by the Silicon Valley startup Nuro.

The startup, founded by Google veterans, raised $940 million in February and has already been delivering groceries for Kroger around Houston. Partnering with the pizza juggernaut Domino's, which delivers close to 3 million pizzas a day, is another logical step for the expanding drone car business.

Kevin Vasconi of Domino's explained in a press release that they see these specially-designed robots as "a valuable partner in our autonomous vehicle journey," adding "The opportunity to bring our customers the choice of an unmanned delivery experience, and our operators an additional delivery solution during a busy store rush, is an important part of our autonomous vehicle testing."

How will they work exactly? Nuro explained in its own press release that this "opportunity to use Nuro's autonomous delivery" will be available for some of the customers who order online. Once they opt in, they'll be able to track the car via an app. When the vehicle gets to them, the customers will use a special PIN code to unlock the pizza compartment.

Nuro and its competitors Udelv and Robomart have been focusing specifically on developing such "last-mile product delivery" machines, reports Arstechnica. Their specially-made R1 vehicle is about half the size of a regular passenger car and doesn't offer any room for a driver. This makes it safer and lighter too, with less potential to cause harm in case of an accident. It also sticks to a fairly low speed of under 25 miles an hour and slams on the breaks at the first sign of trouble.

What also helps such robot cars is "geofencing" technology which confines them to a limited area surrounding the store.

For now, the cars are still tracked around the neighborhoods by human-driven vehicles, with monitors to make sure nothing goes haywire. But these "chase cars" should be phased out eventually, an important milestone in the evolution of your robot pizza drivers.

Check out how Nuro's vehicles work: