We know our dogs love us, and researchers think dogs are capable of plenty of other complex emotions.

So, it's probably not a surprise to most dog owners, but a new study shows that dogs and their people can synchronize their emotions, specifically their stress levels.

Researchers at Linkoping University in Sweden asked owners of 58 border collies and Shetland sheepdogs to fill out questionnaires about their own personalities, as well as the personalities of their dogs.

The owners, who all happened to be female, answered questions about traits such as extraversion, agreeableness, conscientiousness, neuroticism and openness. They also scored their dogs on factors including activity/excitability, responsiveness to training, aggression towards people, aggression towards animals, and fearfulness.

Researchers took hair samples from the owners and the dogs to test for the stress hormone cortisol. They took samples in both summer and winter and found that both times, the cortisol levels in dogs seemed to mirror the levels in their owners.

Mirroring the owner's stress

Researchers found that owners with higher stress levels tended to have dogs with higher stress levels too. The findings were published in Scientific Reports.

"If the owner is stressed, then the dog is also likely to mirror that stress," study co-author Lina Roth, a professor at Linkoping University, told NPR. "It was the owner’s personality that influenced the dog's hair cortisol level, rather than the dog's personality itself."

Researchers also found that the stress correlation was higher between dogs and owners that compete together in disciplines like agility and obedience. They speculate that because they spend so much time together, the training could increase the emotional bond.

But just because your dog is tuned in to your emotions and stress, don't worry that your anxiety is hurting your pet.

"I don't think you should be anxious that, if you're stressed, you might harm your dog," Roth says. "Instead, your dog is a social support for you, and you are a social support for the dog."

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.

Your stress may be stressing out your dog
Dogs pick up on their owners' anxiety and mirror their stress, new study finds.